Installation & Maintenance Manual IM 483-6 Group: Applied Systems Part Number: 571477Y-02 Date: December 1996 MicroTech Applied Rooftop Unit Controller Used with McQuay models: RPS, RFS, RCS, RDT, RDS & RAH 1996 McQuay International
Introduction... 4 General Description... 5 Component Data... 5 Microprocessor Control Board... 6 ADI Board... 8 Output Board A... 9 Output Board B (Compressor Staging)... 10 Output Board C (Electric Heat Staging)... 10 Staging Boards 1 & 2... 10 Relays... 11 Keypad/Display... 11 Temperature Sensors... 12 Pressure Transducers... 12 Actuators... 12 Software Identification... 12 Software Part Number... 13 Software Configuration Code... 13 MicroTech Monitoring and Networking Options... 13 PC Monitoring... 13 Remote Monitoring and Control Panel... 14 Network Master Panel... 14 Open Protocol... 14 Field Wiring... 15 Relay Outputs... 15 Remote Alarm Output... 15 Occupied Output... 15 VAV Box Output... 15 Staged Cooling Outputs... 17 Analog Inputs... 17 Zone Temperature Sensor Packages... 17 Tenant Override (Timed)... 18 Miscellaneous Temperature Sensors... 18 External Reset Signal... 19 Table of Contents Digital Inputs... 19 External Time Clock or Tenant Overrride (Nontimed)... 19 Remote Monitor Panel... 20 External Exhaust Fan Status... 21 Cooling Alarm Inputs (RDS & RAH Units Only)... 21 Communications... 21 PC Connection... 21 Network Connection... 21 Service Information... 22 Controller Inputs... 22 Analog Inputs... 22 Digital Inputs... 25 Controller Outputs... 27 Output Board OBA... 27 Output Board OBB... 33 Output Board OBC... 34 Compressorized Cooling Staging Sequences... 34 Power and Auxiliary Connections... 36 Connections to MCB1... 36 Typical Wiring Diagrams... 37 Test Procedures... 45 MCB1 Status LED Diagnostics... 45 Troubleshooting Power Problems... 45 Troubleshooting Digital Input Problems... 47 Troubleshooting Analog Input Problems... 47 Troubleshooting Output Boards... 50 Troubleshooting Solid-State Relays... 52 Troubleshooting Staging Boards... 54 Troubleshooting the Keypad/Display... 54 MCB1 Replacement... 55 Parts List... 56 Page 2 / IM 483-6 McQuay, MicroTech, and RoofPak are registered trademarks of McQuay International. Monitor is a trademark of McQuay International. Microsoft and MS-DOS are registered trademarks of Microsoft Corporation. Windows is a trademark of Microsoft Corporation. IBM is a registered trademark of International Business Machines Corporation.
Figures: List of Illustrations Tables: 1. Typical MicroTech Control Panel Layout - 018C - 040C, 800C & 802C... 6 2. Typical MicroTech Control Panel Layout 045C - 135C, 047C & 077C... 6 3. Microprocessor Control Board (MCB1)... 6 4. Hex Switches... 8 5. ADI Board... 9 6. Output Board A (OBA)... 9 7. Output Board B or C (OBB or OBC)... 10 8. Staging Board 1 or 2 (SB1 or SB2)... 11 9. Keypad/Display... 11 10. Software ID Tag... 12 11. Zone Sensor Only Field Wiring... 18 12. Zone Sensor with Tenant Override Field Wiring... 18 13. Remote Monitor Panel... 20 14. Electrical Schematic Legend... 37 15. Input Schematic: VAV Units... 38 16. Input Schematic: CAV-ZTC Units... 39 17. Input Schematic: CAV-DTC Units... 40 18. Output Schematic: Fan Start/Stop Control... 41 19. Output Schematic: Actuator Control... 41 20. Output Schematic: Condensing Section Control... 42 21. Output Schematic: Modulating Gas Heat Control... 43 22. Output Schematic: Multi-stage Elec. Heat Control... 44 23. MCB1 Power Supply Terminals... 45 24. Pressure Transducer Voltages: Duct Static and Filter. 50 25. Pressure Transducer Voltages: Building Static... 50 26. Output Board Relay Socket... 51 27. Testing a Typical Relay Circuit... 53 28. Testing a Relay Circuit with a Disconnection... 53 1. Program-Specific Rooftop Unit Operation Literature.. 4 2. Model-Specific Rooftop Unit Installation Literature... 4 3. Green and Red Status LED Indication... 7 4. Amber Status LED & Alarm Output LED Indication.. 8 5. Program Identification... 13 6. PC Specification... 14 7. MicroTech Zone Temperature Sensors... 17 8. Analog Inputs for Program ART1 or ART3 Units... 22 9. Analog Inputs for Program ART2 or ART4 Units... 23 10. Analog Inputs for Program ART5 Units... 23 11. Analog Inputs for Program ART6 Units... 24 12. Analog Inputs for Program ART7 Units... 24 13. Analog Inputs for Program ART8 Units... 24 14. Digital Inputs for Program ART1 or ART3 Units... 25 15. Digital Inputs for Program ART2 or ART4 Units... 25 16. Digital Inputs for Program ART5 Units... 26 17. Digital Inputs for Program ART6 Units... 26 18. Digital Inputs for Program ART7 or ART8 Units... 27 19. OBA Outputs for Program ART1 or ART2 Units... 27 20. OBA Outputs for Program ART3 or ART4 Units... 28 21. OBA Outputs for Program ART5 Units... 28 22. OBA Outputs for Program ART6 Units... 29 23. OBA Outputs for Program ART7 or ART8 Units... 29 24. Cool Outputs (OBA)... 30 25. Heat Outputs (OBA)... 32 26. OBB Outputs for 1-Compr./3-Stage Config.... 33 27. OBB Outputs for 2-Compr./4-Stage Config.... 33 28. OBB Outputs for 4-Compr./4-Stage Config.... 33 29. OBB Outputs for 2-Compr./6-Stage Config.... 33 30. OBB Outputs for 4-Compr./8-Stage Config.... 34 31. OBB Outputs for 3-, 4-, 6-, or 8-Stage Cooling By Others (RDS or RAH Only)... 34 32. OBB Outputs for 6-Stage Electric Heat Config.... 34 33. Compressor Staging Sequences... 34 34. MCB1 Power In Terminal Strip Connections... 36 35. MCB1 Aux/Out Terminal Strip Connections... 36 36. Thermistor Chart... 49 IM 483-6 / Page 3
Introduction This manual provides information about the MicroTech control system used in the McQuay RoofPak applied rooftop unit product line. It describes the MicroTech components, input/output configurations, field wiring options and requirements, and service procedures. For a description of operation and information on using and programming the MicroTech unit controller, refer to the appropriate program-specific operation manual (see Table 1). For installation and commissioning instructions and general information on a particular rooftop unit, refer to its modelspecific installation manual (see Table 2). Table 1. Program-specific rooftop unit operation literature ROOFTOP UNIT CONTROL CONFIGURATION Variable Air Volume (VAV) Constant Air Volume, Zone Temperature Control (CAV-ZTC) Constant Air Volume, Discharge Temperature Control (CAV-DTC) PROGRAM* ART1 ART2 ART3 ART4 ART5 ART7 ART6 ART8 OPERATION MANUAL BULLETIN NUMBER OM 108 OM 109 OM 110 * Program numeration is explained in the Software Identification section of this manual; see Table 5. Table 2. Model-specific rooftop unit installation literature INSTALLATION & MAINTENANCE DATA ROOFTOP UNIT MODEL BULLETIN NUMBER RPS (45-135 tons) RFS (45-135 tons) IM 485 RCS (45-135 tons) RDT IM 486 RAH IM 487 RPS (18-40 tons) RFS (18-40 tons) IM 157 RCS (18-40 tons) RDS (800-802) IM 178 This equipment generates, uses and can radiate radio frequency energy and, if not installed and used in accordance with this instruction manual, may cause interference to radio communications. It has been tested and found to comply with the limits for a Class A digital device, pursuant to part 15 of the FCC rules. These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment. Operation of this equipment in a residential area is likely to cause harmful interference in which case the user will be required to correct the interference at his own expense. McQuay International disclaims any liability resulting from any interference or for the correction thereof. Electric shock hazard. Can cause personal injury or equipment damage. This equipment must be properly grounded. Connections and service to the MicroTech control panel must be performed only by personnel that are knowledgeable in the operation of the equipment being controlled. Page 4 / IM 483-6
Excessive moisture in the control panel can cause hazardous working conditions and improper equipment operation. When servicing this equipment during rainy weather, the electrical components in the main control panel must be protected from the rain. Extreme temperature hazard. Can cause damage to system components. This MicroTech controller is designed to operate in ambient temperatures from -20 F to 125 F. It can be stored in ambient temperatures from -40 F to 140 F. It is designed to be stored and operated in relative humidity up to 95% (non-condensing). Static sensitive components. A static discharge while handling electronic circuit boards can cause damage to the components. Discharge any static electrical charge by touching the bare metal inside the main control panel before performing any service work. Never unplug any cables, circuit board terminal blocks, relay modules, or power plugs while power is applied to the panel. Compressor pumpdown is required before removing power to the controller or unit damage could occur. General Description The MicroTech Applied Rooftop Unit Controller is a microprocessor-based control system designed to provide sophisticated control of McQuay RoofPak applied rooftop units. In addition to providing normal temperature and static pressure control, the controller is capable or providing alarm monitoring and alarm-specific component shutdown if critical system conditions occur. A 12-key keypad and a 2-line by 16-character display give the operator access to temperatures, pressures, operating states, alarm messages, setpoints, control parameters, and schedules. The controller includes password protection to protect against unauthorized or accidental setpoint or parameter changes. This MicroTech controller is capable of complete, stand-alone rooftop unit control. If desired, it can be incorporated into a building-wide network with other MicroTech unit and auxiliary controllers. Regardless of whether the controller is stand-alone or included in a network, an IBM compatible computer containing Monitor software can be connected to give the operator full-screen unit monitoring and control capability. The computer can be connected directly or via telephone lines with an optional modem. Component Data The MicroTech control panel layouts are shown in Figures 1 and 2. The main components of the control system are the Microprocessor Control Board (MCB1), the ADI Board, Output Board A (OBA), and the Keypad/Display. The panel layout shown in Figure 1 includes the optional cooling staging board (SB1) and its associated output board (OBB). The panel layout shown in Figure 2 includes the optional cooling and heating staging boards (SB1 and SB2) and their associated output boards (OBB and OBC). All of these major components are interconnected by ribbon cables, shielded multi-conductor cables, or discrete wiring. Power for the system is provided by transformers T2 and T3. Following are descriptions of these MicroTech components and their input and output devices. IM 483-6 / Page 5
Figure 1. Typical MicroTech control panel layout - 018C - 040C, 800C & 802C Figure 2. Typical MicroTech control panel layout - 045C - 135C, 047C & 077C Microprocessor Control Board The Microprocessor Control Board (MCB1) is shown in Figure 3. It contains a microprocessor that is preprogrammed with the software required to monitor and control the unit. MCB1 receives input signals, processes them, and sends appropriate commands to the output relays. The various MCB1 connections and components are described below. Figure 3. Microprocessor Control Board (MCB1) Power In (18-24 VCT) AC AC GND GND Keypad/LCD Display 4 3 2 1 9 8 7 6 5 4 3 2 1 HI LO Address Hex Switches Microprocessor Status LEDs Running Reset Active Spare Aux/Out CPU Status Output 0 Fuse Power Fuses (Bussman GDC-T2A) Digital Outputs (To OBA) 1 2 3 4 Port A Port B Communications (Fuse: Bussman MCR-1/4) Digital Inputs (ADI Board) Analog Inputs (ADI Board) Page 6 / IM 483-6
Analog inputs connection Conditioned analog input signals are received from the ADI Board through the Analog Inputs port via a plug-in ribbon cable. These inputs are 0 to 5 VDC analog signals. Digital inputs connection Digital input signals are received from the ADI Board through the Digital Inputs port via a plug-in ribbon cable. These inputs are 0 VDC or 5 VDC. Digital outputs connection After processing all input conditions, MCB1 sends the appropriate output signals to OBA through the Digital Outputs port via a plug-in ribbon cable. Aux/Out terminal strip The Aux/Out terminal strip provides 13 VDC power for the optional staging boards (SB1 and SB2) and 5 VDC power for the OBA, any actuator feedback pots, and the remote setpoint pots (if used). It also provides the staging signals to SB1 and SB2. A schedule of the Aux/Out connections is included in the Power Auxiliary Connections section of this manual. Refer to this section and the unit wiring diagrams for more information. Power in terminal strip MCB1 receives 18 VAC center tapped power from transformer T3 through the Power In terminal strip. This power drives all logic and input reference circuitry., the Aux/Out terminal strip, and the Keypad/Display. A schedule of the Power In connections is included in the Power and Auxiliary Connections section of this manual. Refer to this section and the unit wiring diagrams for more information. Power fuses Two identical fuses are located to the right of the Power In terminal strip. The fuses are in the 18 VAC input power supply circuit. Microprocessor status LEDs The green, red, and amber LEDs on MCB1 provide information about the operating status of the microprocessor. The amber LED also indicates the existence of alarm conditions in the unit. Note that the remote alarm output relay (OBA0) is driven by the same signal that drives the amber LED. For more information on the remote alarm output, refer to the Relay Outputs section of this manual. Following is the normal start-up sequence that the three status LEDs should follow when power is applied to MCB1: 1. The red ( Reset ) LED turns on and remains on for approximately 5 seconds. During this period MCB1 performs a self-test. 2. The red LED turns off and the green ( Running ) LED turns on. This indicates that the microprocessor has passed the self-test and is functioning properly. 3. The amber ( Active ) LED turns on and remains on continually if no alarm conditions exist in the unit. This indicates the programmed routines are executing. The condition of the amber LED when an alarm occurs in the unit can be set to either Blink or Off at the unit keypad. Refer to the appropriate program-specific operation manual (see Table 1). If it is set to Blink the LED will flash as shown in Table 4. If it is set to Off the LED will turn off and remain off until the alarm is cleared. If the above sequence does not occur after power is applied to the controller, there is a problem with MCB1. For more information, refer to the Test Procedures section of this manual. Tables 3 and 4 summarize the green, red, and amber status LED indications. Table 3. Green and red status LED indication GREEN LED STATE RED LED STATE Off Off No power to MCB1 Off On* Self-test failure or power supply problem On Off MCB1 operating normally * For longer than 5 seconds. IM 483-6 / Page 7
4 4 Table 4. Amber status LED and alarm output LED indication AMBER LED & OBA0 LED STATE Off Continually Normal operation 1) No power to MCB1 or programmed routines not executing (with alarm output set to Off Blink ) 2) Alarm condition (with Alarm Output set to Off ) On 1/2 second; Alarm condition (with Alarm Output set to Off 1/2 second Blink ) On 9/10 second; Off 1/10 second Dirty filter (with Alarm Output set to Blink ) Keypad/LCD display connection MCB1 receives input commands and operates parameters from the keypad and sends requested information to the display through the Keypad/LCD Display port via a plug-in ribbon cable. Hex switches MCB1 includes two hex (hexadecimal) switches that are used to set the network address for units that are part of a MicroTech network. For more information on network applications, refer to the MicroTech Monitoring and Networking Options section of this manual. The HI and LO hex switches are shown in Figure 4. A hex switch setting is defined as the HI switch digit followed by the LO switch digit. For example, a hex switch setting of 2F would have the HI switch set to 2 and the LO switch set to F. The factory set hex switch setting should be 01. If the unit is not part of a network, leave the switches at the factory setting. Note: If the hex switch setting is changed, power to MCB1 must be cycled in order to enter the new setting into memory. This can be done by opening and then closing system switch S1 in the main control box. If the unit is equipped with compressors, they must be pumped down before system switch S1 is opened. Figure 4. Hex switches A B C DE F 9 HI 0 1 2 3 5 6 7 8 A B C DE F 9 LO 0 1 2 3 5 6 7 8 Page 8 / IM 483-6 Communication ports MCB1 has two communication ports: Port A and Port B. Each port has six terminals and is set up for either an RS-232 or RS-485 communications format. Following are brief descriptions of each port s function. For further information, refer to the MicroTech Monitoring and Networking Options section of this manual. Port A: Port A is for communications with an IBM compatible PC using the RS-232 format. The PC can be directly connected, over a limited distance, using a twisted, shielded pair cable, or it can be remotely connected via phone lines using an optional modem. The default communications rate is 9600 baud. Port B: Port B is for MicroTech network communications using the RS-485 format. In a network application, all MicroTech unit controllers and auxiliary panels are connected together in a daisy-chain manner with a twisted, shielded pair cable. The default communications rate is 9600 baud. ADI Board The ADI Board is shown in Figure 5. It collects all analog and digital input information, converts it into 0 to 5 VDC signals, and sends them to MCB1 via plug-in ribbon cables. The various ADI inputs, connections, and components are described below. Digital inputs The 12 possible digital inputs to the ADI board are connected at terminal strips DH1 and DH2. LEDs 0 through 11 indicate the status of each digital input. Note: Digital inputs 12-15 are spares. When the input device s switch or contacts close, its associated LED will glow. Digital input schedules for the
various rooftop unit configurations are included in the Controller Inputs section of this manual. Refer to this section and the unit wiring diagrams for more information. Analog inputs The 14 possible analog inputs to the ADI Board are connected at terminal strips AH1, AH2, AH3 and AH4. AH1 is for analog inputs A0-A3, AH2 is for A4-A7, AH3 is for A8-A11 and AH4 is for A12-A15 (A14 & A15 are spares). Analog input schedules for the various rooftop unit configurations are included in the Controller Inputs section of this manual. Refer to this section and the unit wiring diagrams for more information. Figure 5. ADI board Output Board A Output Board A (OBA) is shown in Figure 6. It can hold up to 16 solid-state, plug-in relays, which are labeled OBA0 through OBA15 (see Relays below). The number of relays installed on OBA depends upon the quantity and types of options installed in the unit. Each output has an associated LED that will light when the relay is energized. Output board OBA requires 5 VDC power, which is supplied to it from the Aux/Out terminal strip on MCB1. The relay switching signals are supplied to it from MCB1 via a plug-in ribbon cable. Listings of the OBA relay outputs for the various rooftop unit configurations are included in the Controller Outputs section of this manual. Refer to this section and the unit wiring diagrams for more information. Figure 6. Output board A (OBA) Socket Shown with Relay Removed 1 2 34 5 OBA15 OBA14 OBA13 OBA12 Solid-State Relays OBA11 OBA10 OBA9 OBA8 Output Connections OBA7 OBA6 OBA5 OBA4 OBA3 OBA2 OBA1 OBA0 Input Control Power (5 VDC) MCB1 Ribbon Cable Connection IM 483-6 / Page 9
Output Board B (compressor staging) Output Board B (OBB) is shown in Figure 7. It is only used if the quantity of available OBA relays is insufficient to accommodate the required number of rooftop unit compressorized cooling stages. If OBB is required, it is always used in conjunction with staging board SB1 (see below). OBB may have 4 or 8 sockets, and it can hold up to 8 solid-state plug-in relays, which are labeled OBB0 through OBB7 (see Relays below). Each output has an associated LED that will light when the relay is energized. Output board OBB requires 5 VDC power, which is supplied to it from staging board SB1. The 4- socket OBB is connected to SB1 with discrete wiring, and the 8-socket OBB is connected to SB1 with a plug-in ribbon cable. Listings of the OBB relay outputs for the various compressorized cooling configurations are included in the Controller Outputs section of this manual. Refer to this section and the unit wiring diagrams for more information. Figure 7. Output board B or C (OBB or OBC) Socket Shown with Relay Removed Fuse 1 2 34 5 OBB7 OBB6 Solid-State Relays OBB5 (OBC5) OBB4 (OBC4) OBB3 (OBC3) Output Connections OBB2 (OBC2) OBB1 (OBC1) OBB0 (OBC0) Input Control Power (5 VDC) SB1 or SB2 Ribbon Cable Connection Output Board C (electric heat staging) Output Board C (OBC) is shown in Figure 7. It is only used if the quantity of available OBA relays is insufficient to accommodate the required number of rooftop unit electric heating stages. If OBC is required, it is always used in conjunction with staging board SB2 (see below). OBC has 8 sockets, and it holds 6 solid-state, plug-in relays, which are labeled OBC0 through OBC5 (see Relays below). Each output has an associated LED that will light when the relay is energized. Output board OBC requires 5 VDC power, which is supplied to it from staging board SB2. The relay switching signals are also supplied to OBC from SB2 via a plug-in ribbon cable. A listing of the OBC relay outputs for the 6-stage electric heating configuration is included in the Controller Outputs section of this manual. Refer to this section and the unit wiring diagrams for more information. Staging boards 1 and 2 Staging boards SB1 and SB2 are shown in Figure 8. They are used only if the quantity of available OBA relays is insufficient to accommodate the required number of compressorized cooling or electric heating stages. If SB1 is required, it is always used in conjunction with staging board OBB for cooling, and if SB2 is required, it is always used in conjunction with OBC for electric heating. The staging boards require 13 VDC power which is supplied to them from the Aux/Out terminal strip on MCB1. MCB1 also supplies each staging board with two staging signals: one indicates whether the stage change is required and the other indicates whether the stage change should be up or down. The staging boards process these signals and send them to their respective output boards (OBB or OBC). When lit, LED s L1 through L8 indicate the number of stages currently in operation. Page 10 / IM 483-6
For compressorized cooling applications that require a staging board, compressor lead-lag is set at SB1 using a movable jumper. When lit, LED L9 indicates that compressor 1 is lead, and LED L10 indicates that compressor 2 is lead. For more information on the lead-lag feature, refer to Compressor Lead-Lag in the Cooling: Multistage section of the applicable operation manual (see Table 1). Figure 8. Staging Board 1 or 2 (SB1 or SB2) Stage Indicating LEDs STAGE 8 L8 TSI STAGE 7 STAGE 6 STAGE 5 STAGE 4 STAGE 3 STAGE 2 STAGE 1 L9 L7 L6 L5 L4 L3 L2 L1 L10 OBB or OBC Ribbon Cable Connection 1 2 3 4 Lead-Lag Indicating LEDs 1 2 3 4 5 6 TS2 Relays The relays used with output boards OBA, OBB, and OBC are solid-state. They are rated for a maximum load of 1.8A at 149 F (65 C), and unlike electromechanical relays, they require a minimum load of 30 ma. They can operate in 24 to 140 VAC circuits. These solid-state relays have normally open contacts that close whenever their coils are energized. When this occurs, an associated LED mounted on the output board will glow. Actually, contacts and coils do not exist in a solid-state relay as they do in an electromechanical relay. However, for clarity, these electromechanical terms will be used throughout this manual and the associated operation manuals. For more detailed information, refer to Troubleshooting Solid-State Relays in the Test Procedures section of this manual. Keypad/Display The Keypad/Display, shown in Figure 9, provides the operator to local interface with MCB1. All operating conditions, system alarms, control parameters, and schedules can be monitored from the display. If the password has been entered, any adjustable parameter or schedule can be modified with the keypad. For information on using the Keypad/Display, refer to the Getting Started portion of the applicable operation manual (see Table 1). Figure 9. Keypad/Display CATEGORY MENU ITEM ACTION STATUS ALARMS PREV. PREV. INCR. CLEAR CONTROL SWITCH NEXT NEXT DECR. ENTER IM 483-6 / Page 11
Temperature sensors The MicroTech controller uses negative temperature coefficient (NTC) thermistors for temperature sensing. A thermistor chart, which provides voltage-to-temperature and resistance-to-temperature conversion data (Table 37), is included in the Test Procedures section of this manual. Pressure transducers The MicroTech controller uses 0 to 5" wc, 1 to 6 VDC static pressure transducers for measuring filter pressure drop and, if necessary, duct static pressure and final filter pressure drop. If building static pressure control is required, a -0.25 to 0.25" wc, 1 to 5 VDC static pressure transducer is also used. Voltage-to-pressure conversion data is included in the Test Procedures section of this manual (Figures 24 and 25). The Calibrate feature automatically shuts down the unit and zeroes all pressure transducer inputs to MCB1. For more information on Calibrate, refer to Control Mode in the Auto/Manual Operation section of the applicable operation manual (see Table 1). Actuators The MicroTech controller uses floating-control actuators for valve, damper, and variable inlet vane modulation. They are controlled using the Step-and-Wait control algorithm. The valves, mixing dampers, and optional isolation dampers have spring-return actuators. All cooling and heating valves are normally open, and the outside air and isolation dampers are normally closed. On units equipped with face and bypass (F&BP) dampers, a spring-return, two-position end-of-cycle (EOC) valve is used to prevent overheating or overcooling when the dampers are in the full bypass position. All EOC valves are normally open. Actuator position feedback is supplied to the controller for the outside air damper and the supply and return fan inlet vanes (or discharge dampers). The Calibrate feature automatically shuts down the unit and records the position feedback values for these actuators after they have been driven fully open and fully closed. For more information on Calibrate, refer to Control Mode in the Auto/Manual Operation section of the applicable operation manual (see Table 1). Software Identification MicroTech Applied Rooftop Unit Controller software is factory installed and tested in each unit prior to shipment. The software is identified either by a software part number or a software ID and a software configuration code. The software part number and configuration strings are printed on the software ID tag, a small label affixed to the control panel next to MCB1. Refer to Figure 1 or 2. An example of the software ID tag is shown in Figure 10. The software ID number is encoded in the controller s memory and is available for display on menu 28 of the Keypad/Display. (See the applicable operation manual for information on using the Keypad/ Display). Using menu 28 of the Keypad/Display is the most reliable way of determining the controller s software part number. Note: Over time, changes to the controller software may be required because of software updates or new job requirements. It is recommended that these changes (if any) be documented and kept in a safe place. If MCB1 fails and needs to be replaced, this record will help to ensure that the new MCB1 board is loaded with the proper software. For more information, see the MCB1 Replacement section of this manual. Figure 10. Software ID tag Software Part Number Software Configuration Code Part No. 571573B-01-0 Page 12 / IM 483-6
Software part number Table 5 shows the eight standard software part numbers and ID numbers used by the various types of applied rooftop units. Software part number codification is as follows: Program number Version (numeric) Version revision (zero then alphabetical) 950164 05 A If the unit s program number does not match one of those listed in Table 5, it means that a special program has been loaded into the controller. In this case, the information in this manual and the associated operation manuals that is related to standard software may not be applicable. For brevity, a program tag has been assigned to each standard program number. The program tag will be used throughout this manual and the associated operation manuals to identify and classify the various types of rooftop units. For example, if a table pertains to ART1 and ART3 units, it is referring to VAV units with fan tracking control. If it pertains to ART1 and ART2 units, it is referring to VAV units with no heat or one-stage of heat. Note: The leading 9 of the software part number is not printed on the software ID tag. Software configuration code The software configuration code string defines how a standard program has been modified to match the specific options that are present in a particular unit. For example, it describes the type of outside air damper control, the types of cooling and heating equipment (if any), the number of stages, the airflow modulation method (if any), and the number of static pressure sensors (if any). If a controller is equipped with a special program, the software configuration code usually is not applicable and is not printed on the software ID tag. Because of its complexity, configuration string codification will not be explained here. The software configuration code is written on the software ID tag for the use of factory service personnel. Table 5. Program identification PROGRAM TAG SOFTWARE PART NO. ROOFTOP UNIT DESCRIPTION ART1 950164*** VAV, Cooling Only or Cooling/One-Stage Heat with Fan Tracking Control ART2 950314*** VAV, Cooling Only or Cooling/One-Stage Heat with Building Static Control ART3 950162*** VAV, Cooling/Modulating Heating with Fan Tracking Control ART4 950313*** VAV, Cooling/Modulating Heating with Building Static Control ART5 950163*** CAV, Zone Temperature Control (ZTC), Mixed Air or 100% Return Air ART6 950315*** CAV, Discharge Temperature Control (DTC), Mixed Air or 100% Return Air VAV, Air Volume Modulation By Others ART7 950166*** CAV, Zone Temperature Control (ZTC), 100% Outdoor Air ART8 950316*** CAV, Discharge Temperature Control (DTC), 100% Outdoor Air MicroTech Monitoring and Networking Options PC monitoring A personal computer (PC) equipped with the appropriate MicroTech Monitor software can be used to provide a high-level interface with the MicroTech controller (see PC specification below). MicroTech Monitor Software features a high resolution graphic display, multilevel password access, and advanced trend logging. The PC can be connected to the controller either directly via a single twisted, shielded pair cable or remotely via phone lines with an optional modem. If the controller is part of a MicroTech network (see below), PC monitoring can be done via network communications. For more information on connecting the PC to the controller, refer to the Communications section of this manual. For maximum convenience and functionality, the PC should be considered dedicated to the MicroTech system. However, the operator can exit the Monitor program to perform other tasks without affecting equipment control. Refer to the user s manual supplied with the Monitor software for additional information. IM 483-6 / Page 13
PC specification A direct or remote connected computer can be used for monitoring unit operation, changing setpoints, scheduling, trend logging, downloading software, and diagnostics. The PC must be an IBM or 100% true compatible. Table 6 shows the minimum and preferred PC specifications. Table 6. PC specification PREFERRED CONFIGURATION MINIMUM CONFIGURATION 486DX microprocessor, 66MHz or better 386SX microprocessor, 16MHz 8 MB of RAM or more 4MB of RAM 120 MB hard disk drive or larger 60 MB hard disk drive 3 1/2" floppy disk drive 3 1/2" floppy disk drive Serial port (9 pin male; Com1 or Com2) Serial port (9 or 25 pin male; Com1 or Com2) Parallel port Internal time clock, battery backed Internal time clock, battery backed Super VGA graphics capability VGA graphics capability Super VGA monitor VGA monitor Printer Bus mouse or trackball Serial mouse or trackball* 101 enhanced keyboard 101 enhanced keyboard 9600 baud or higher modem compatible with the AT 1200 baud modem, compatible with the AT command set command set (optional) (optional) MS-DOS 6.2 or higher MS-DOS 5.0 Microsoft Windows 3.1 or higher Microsoft Windows 3.1 MicroTech Monitor software MicroTech Monitor software * If a serial device is used, there must be another serial port (Com1 or Com2) available for connecting the PC to the MicroTech controller. Remote monitoring & control panel One to as many as eight applied rooftop units can be incorporated into a network with the MicroTech Remote Monitoring and Control (RMC) Panel. The optional RMC Panel provides the following capabilities: Remote unit monitoring (up to 8 units) Common temperature and pressure control of multiple units (groups of 2 to 8) Common unit scheduling The RMC Panel is connected to the unit controllers in a daisy-chain manner via a single twisted, shielded pair cable. For further information, refer to Bulletin No. IM 444, MicroTech Remote Monitoring and Control Panel. Network master panel The MicroTech Network Master Panel (NMP) allows multiple Applied Rooftop Unit Controllers to be incorporated into a building-wide network with other MicroTech unit and auxiliary controllers. In conjunction with a PC, it provides the building operator with the capability to perform advanced equipment control and monitoring from a central or remote location. The NMP can be used with or without the RMC Panel (see above). The following features are provided by the optional NMP: Remote unit monitoring Advanced scheduling features Advanced alarm management Global operator override by unit type Demand metering Historical electrical date logging The NMP is connected to the unit and auxiliary controllers in a daisy-chain manner via a single twisted, shielded pair cable. For further information, contact your local McQuay representative. Open protocol MicroTech Open Protocol provides an interface between the Applied Rooftop Unit Controller and the building automation system of one of many participating manufacturers. With the Open Protocol, the building automation system can do the following: Page 14 / IM 483-6 Set the operating mode Monitor most controller inputs, outputs, setpoints, parameters, and alarms Set most controller setpoints and parameters Clear alarms Reset the cooling discharge air temperature setpoint (VAV and CAV-DTC units)
Reset the heating discharge air temperature setpoint (VAV and CAV-DTC units with modulating heat) Reset the duct static pressure setpoint (VAV units) Set the heat/cool changeover temperature (Control Temperature for VAV and CAV-DTC units) Set the representative zone temperature (Control Temperature for CAV-ZTC units) For specific information on Open Protocol applications and availability contact your local McQuay representative. Field Wiring Following are descriptions of the various options and features that may require field wiring to the MicroTech controller. Refer to the job plans and specifications. For more information on the electrical installation, refer to Field Control Wiring in the Electrical Installation section of the applicable installation manual (see Table 2). Relay Outputs The following relay outputs may be available for field connections to any suitable device: Remote alarm output (OBA0) Occupied output (OAB15/R26) VAV box output (OBA6) Staged cooling outputs (OBA1 and OBA2 or OBB0-OBB7) The remote alarm output and occupied outputs are available on all units. The VAV box output is available only on VAV units (programs ART1, ART2, ART3, ART4, and ART6). The optional staged cooling outputs are available only on model RAH units to be used with field supplied cooling equipment. Remote alarm output The remote alarm output (OBA0) can be used to provide a remote alarm signal. It is energized by the same signal that lights the amber status LED on MCB1 (see Table 4). Note that its contacts are closed and its associated LED on OBA is lit during normal operation. A 24 VAC power supply and load can be connected to remote alarm output OBA0 at terminals 114 and 115 on terminal block TB2. (Note that although the solid-state relays can operate in 24 to 140 VAC circuits, 24 VAC power must be used in circuits wired to terminal block TB2.) For further information on solid-state relays, refer to Relays in the Component Data section of this manual. Occupied output The occupied output (OBA15/R26) can be used to control field equipment that depends on fan operation (field installed isolation dampers, VAV boxes, etc.) It is energized 3 minutes before fan startup and remains energized during fan operation. It is de-energized 3 minutes after fan shutdown and remains de-energized while the fans are off. Note that the occupied output will always operate as described above regardless of whether the unit is in the occupied or unoccupied mode. Occupied output OBA15 is connected to relay R26 in the MicroTech control panel. Any low voltage wiring can be connected to the normally open dry contacts of R26 at terminals 116 and 117 on terminal block TB2. When the occupied output is in the occupied (fan on) state, the OBA15 LED will glow, and the R26 contacts will be closed. When the occupied output is in the unoccupied (fan off) state, the OBA15 LED will be off, and the R26 contacts will be open. VAV box output The VAV box output (OBA6) provides a means of interfacing unit and VAV box control. Field use of it is optional; however, it is highly recommended, especially for VAV systems that have heating capability (unit or duct mounted). A 24 VAC power supply and load can be connected to VAV box output OBA6 at terminals 118 and 119 on terminal block TB2. (Note that although the solid-state relays can operate in 24 to 140 VAC circuits, 24 VAC power must be used in circuits wired to terminal block TB2.) For further information on solid-state relays, refer to Relays in the Component Data section of this manual. Following are application guidelines for the four basic rooftop unit heating configurations. For all of these configurations, the OBA6 relay contacts will be open for an adjustable time period after unit start-up (default is 3 minutes). During this period (the Recirculate state), heating and cooling will be IM 483-6 / Page 15
disabled, and the outside air damper will be held closed. The fans will operate, circulate building air and equalizing space, duct, and unit temperature conditions. For more information on VAV box output operation, refer to the Operating States and Sequences section of the applicable VAV or CAV-DTC operation manual (see Table 1). Cooling only units For cooling only VAV systems, the VAV box output can be used to override zone thermostat control and drive the VAV boxes fully open to facilitate air circulation during the Recirculate period. During this time, the OBA6 relay contacts will be open. Cooling only units (programs ART1 and ART2) have a Post Heat control feature which forces the supply air volume to a minimum level before closing the VAV box output when the Recirculate period is over. Post Heat acts to prevent excessive duct static pressure conditions that could otherwise occur when the zone thermostats regain VAV box control. When the unit is not in Recirculate or Post Heat, the OBA6 relay contacts will be closed (auto), allowing the zone thermostats to control the boxes. If desired, the occupied output and VAV box output can be wired in series. This will cause the boxes to open when the unit is not operational. Cooling only units with field supplied heat For VAV systems with cooling only rooftop units and duct mounted reheat coils, the VAV box output can be used to override zone thermostat control and drive the VAV boxes fully open when heating is required. Note that, if necessary, the MicroTech controller will energize the fans for night setback and morning warm-up heating operation. When this occurs, the unit will enter and remain in the Unoccupied Heating or Morning Warm-Up Heating state until heat is no longer required. (The temperature control sequences are the same as those for units with factory-equipped heating equipment.) While the unit is in these states, the OBA6 relay contacts will be open. Cooling only units (programs ART1 and ART2) have a Post Heat control feature which forces the VAV box output when the heating period is over. Post Heat acts to prevent excessive duct static pressure conditions that could otherwise occur when the zone thermostats regain VAV box control. When the unit is not in Recirculate, Post Heat or any heating state, the OBA6 relay contacts will be closed (auto), allowing the zone thermostats to control the boxes. If desired, the occupied output and VAV box output can be wired in series. This will cause the boxes to open when the unit is not operational. Units with one-stage heat The VAV box output should be used to override zone thermostat control and drive the VAV boxes fully open when heating is required. While the unit is in Recirculate or any heating state (Unoccupied Heating, Morning Warm-up, or Heating), the OBA6 relay contacts will be open. Units with one stage of heat (programs ART1 and ART2) have a Post Heat control feature which forces the supply air volume to a minimum level before closing the VAV box output after Recirculate or when heat is no longer required. Post Heat acts to prevent excessive duct static pressure conditions that could otherwise occur when the zone thermostats regain VAV box control. When the unit is not in Recirculate, Post Heat, or any heating state, the OBA6 contacts will be closed (auto), allowing the zone thermostats to control the boxes. If desired, the occupied output and VAV box output can be wired in series. This will cause the boxes to open when the unit is not operational. Units with modulating heat The VAV box output should be used to switch the VAV boxes between heating and cooling control. While the unit is in Recirculate or any heating state (Unoccupied Heating, Morning Warm-up, or Heating), the OBA6 relay contacts will be open, switching the boxes to heating control. When the unit is not in Recirculate or any heating state, the OBA6 contacts will be closed (auto), switching the boxes to cooling control. Page 16 / IM 483-6
Staged cooling outputs Model RDS and RAH rooftop air handlers can be ordered with factory-installed evaporator coils and the capability to control 2, 3, 4, 6, or 8 stages of field-supplied cooling equipment. The output relays for 2-stage applications are OBA1 and OBA2. The output relays for 3-, 4-, 6- or 8-stage applications are OBB0 through OBB7, as required. As the controller stages up cooling, it sequentially energizes the normally open relays in ascending order. As the controller stages down cooling, it sequentially de-energizes the relays in descending order. For more information, refer to the unit wiring diagrams and the Controller Outputs section of this manual. A 24 VAC or 115 VAC power supply and load should be connected to each cooling output at the proper terminals on terminal block TB5 (see unit wiring diagram). For further information on solidstate relays, refer to Relays in the Component Data section of this manual. Analog Inputs Zone temperature sensor packages Table 7 lists the three zone temperature sensor packages that are available for use with applied rooftop units. Except for the 100% outdoor air CAV-ZTC unit (program ART7), a zone temperature sensor (ZNT1) is optional for all rooftop units. However, one of the zone sensor packages is required to take advantage of any of the following standard controller features: Unoccupied heating or cooling Pre-occupancy purge Supply air reset from space temperature (VAV and CAV-DTC only) Timed tenant override Remote setpoint adjustment (CAV-ZTC only) Table 7. MicroTech zone temperature sensors TENANT REMOTE MCQUAY FOR USE WITH OVERRIDE SETPOINT PART NO. SWITCH ADJUSTMENT VAV CAV-ZTC CAV-DTC 665404B-01 No No X X X 665404B-02 Yes No X X X 665404B-09 Yes Yes X Zone sensor without remote setpoint adjustment The two standard MicroTech room temperature sensor packages that do not include setpoint adjustment pots can be used with any Applied Rooftop Unit Controller. Refer to Table 7. They are available with or without a tenant override switch. For more information on this switch, see Tenant Override (Timed) below. These zone sensors must be field installed and field wired to the unit using a twisted, shielded pair cable (Belden 8761 or equivalent). Figures 11 and 12 show the required wiring terminations. Refer to Bulletin No. IM 529, MicroTech Room Temperature Sensors, for more information on installing these zone sensor packages. Note: Zone sensor wiring terminations are not shown on the unit wiring diagram. Refer to Figures 11 and 12 instead. Zone sensor with remote setpoint adjustment As shown in Table 7, a wall mounted zone temperature sensor package equipped with cooling and heating setpoint adjustment pots is available for use with CAV-ZTC units (programs ART5 and ART7). This sensor package also includes a tenant override switch. For more information on it, see Tenant Override (Timed) below. If wall mounted cooling and heating setpoint adjustment is not required, use one of the other room temperature sensor packages (see above). This zone sensor package must be field installed and field wired to the unit using twisted, shielded cable. Depending on whether one or both setpoint pots are used, either five or six conductors are required. Cable with 22 AWG conductors is sufficient. Do not install the cable in the same conduit with power wiring. Refer to the unit wiring diagrams or Figure 16 for wiring termination details. Note: The remote setpoint adjustment pots can be enabled or disabled as desired at the controller keypad. When they are enabled, these pots can be used to adjust the zone heating and cooling setpoints IM 483-6 / Page 17
regardless of whether the unit is set up for zone or return air control. Refer to Bulletin No. OM 109, MicroTech Applied Rooftop Unit Controller: CAV-ZTC Control, for more information. Figure 11. Zone sensor only field wiring ZNT1 Zone Sensor Not Used LED 1 3 4 Unit Terminal Block TB2 120 121 A3 Figure 12. Zone sensor with tenant override field wiring Not Used 1 Unit Terminal Block TB2 Tenant Override 2 ZNT1 3 120 121 A3 Zone Sensor 4 Tenant override (timed) The tenant override switch provided with several of the zone temperature sensor packages can be used to override unoccupied operation for a preprogrammed time period. This time period can be adjusted to be between 0 and 5 hours (default is 2 hours). Except for the fact that it is temporary, tenant override operation is identical to occupied operation. When depressed, the pushbutton switch momentarily shorts zone temperature sensor ZNT1, resetting and starting the override timer. For more information on this tenant override switch, see Zone Temperature Sensor Packages above. For information on setting the override timer, refer to the Auto/Manual Operation section of the applicable operation manual (see Table 1). Note: If this tenant override feature is used on a VAV unit, it may be necessary to signal the VAV boxes that the unit is operating. It is recommended that the VAV box output be used for this purpose. Miscellaneous temperature sensors Two analog inputs (A5 and A6) are available for miscellaneous monitor only temperature sensors. If the appropriate sensor is used, it can be used for any purpose. For example, a room sensor can sense zone temperature, a duct sensor can sense mixed air temperature, and a strap-on or immersion sensor can sense hot or chilled water supply temperatures. The operator can monitor these temperatures at the Keypad/Display or at a PC equipped with Monitor software. They are labeled Misc Temp #1 and Misc Temp #2. Miscellaneous temperature sensors must be field installed and field wired to the unit using a twisted, shielded pair cable (Belden 8761 or equivalent). Cable with 22 AWG conductors is sufficient. Do not install the cable in the same conduit with power wiring. Refer to the unit wiring diagrams or Figures 15 through 17 for wiring termination details. Refer to the parts list or contact your local McQuay representative for MicroTech temperature sensor part numbers. Page 18 / IM 483-6
External reset signal Ground loop current hazard. Can cause equipment damage. The external reset signal must be isolated from any ground other than the MicroTech controller chassis ground. If it is not, ground loop currents could occur which could damage the MicroTech controller. If the device or system providing the external reset signal is connected to a ground other than the MicroTech controller chassis, be sure that it is providing an isolated output, or condition the output with a signal isolator. On VAV and CAV-DTC units (programs ART1, ART2, ART3, ART4, ART6, and ART8), there are several optional discharge air temperature reset methods available to the operator. Any method or no reset can be selected for cooling operation or heating operation (modulating only) at the controller keypad. On a given unit, for example, space reset can be selected for cooling operation, and external reset can be selected for hot water heating operation. The external reset option is the only one that requires field wiring to implement. For more information on supply air temperature reset, refer to the Cooling: Multistage, Cooling: Modulating, and Heating: Modulating sections of the applicable operation manual (see Table 1). If selected, the external reset option linearly resets the supply air temperature setpoint between user programmed minimum and maximum values (cooling or heating) as the input signal varies between 1 and 5 VDC. (A 4-20mA signal can be converted to a 1-5 VDC signal by installing a 249, 1%, 1/4 watt resister across the input terminals.) Note that if external reset is selected for both cooling and heating, the device or system providing the reset signal must know when the unit switches between cooling and heating operation. On any VAV unit, the VAV box output can be used for this purpose. The external reset signal must be field wired to the unit using a twisted, shielded pair cable (Belden 8761 or equivalent). Cable with 22 AWG conductors is sufficient. Do not install the cable in the same conduit with power wiring. Refer to the unit wiring diagrams or Figures 15 and 17 for wiring termination details. VAV units On VAV units using program ART1, ART2, ART3, or ART4, the external reset signal can be field connected to the controller at input A7 (terminals 75 and 76 on terminal block TB7). If the optional final filter is installed in one of these units, input A7 is factory wired to the pressure drop transducer (SPS6). Practically, this means that the external reset option is not available on units equipped with final filters. However, if external reset is desired and final filter pressure drop is not required, the SPS6 wiring can be disconnected and replaced with wiring for the external signal. (To disconnect SPS6, remove wires 638, 639, and 640 from terminals 72, 75, and 76.) When external reset is selected, the controller will use the A7 signal for external reset and disable the final filter dirty filter alarm. CAV-DTC units On CAV-DTC units using program ART6 or ART8, the external reset signal is connected to the controller at input A9 (terminals 126 and 127 on terminal block TB2). Regardless of whether the unit is equipped with a final filter, input A9 is always available for the external reset connection. Digital Inputs If used, the following options require field wiring to digital inputs. Except for the Remote Monitor Panel option, field wiring is not required if the option is not used. Refer to Remote Monitor Panel below for more information. Twisted, shielded cable is not required for digital input wiring. External time clock or tenant override (nontimed) There are several methods of switching the rooftop unit between occupied and unoccupied operation. It can be done by the unit controller s internal schedule, a network schedule, an external time clock, or a tenant override switch. If the internal schedule or a network schedule is used, field wiring is not required. If an external time clock or a tenant override switch is used, a set of dry contacts must be field wired to input D1 at terminals 101 and 102 on terminal block TB2. Refer to the unit wiring diagrams or Figures IM 483-6 / Page 19