N-1001 Economizer Logic Network

Transcription

1 , Rev. A N-1001 Economizer Logic Network Product Bulletin N-1001 Issue Date 0316 Features Choice of O.A. Dry Bulb Economizer, Differential Temperature Economizer, or Enthalpy Economizer cycles Compatible with all pneumatic controllers and transmitters Hypodermic needle test points on all inputs and outputs English Language connection identification The N-1001 Economizer Logic Network is a versatile multipurpose pneumatic device which provides a sequence of logic functions to all types of mixed air handling units. Based on cooling demand, fan status, and seasonal input conditions, the N-1001 provides fan interlock and minimum position control features, as well as economizer control and other auxiliary switching strategies. Operation The N-1001 Economizer Logic Network is used in conjunction with a pneumatic controller to provide mixed air economizer and cooling control logic to an air handling unit. The N-1001 receives a controller signal and either repeats the signal or modifies it to provide optimal control of mixed air dampers and cooling apparatus. The choice of either standard dry bulb, differential temperature, or enthalpy economizer is used to determine the Summer or Winter mode of O.A. damper operation. The fan status determines whether the dampers and cooling apparatus are to be operational or closed. An integral adjustable minimum percent O.A. setting provides ventilation. Mounting The N-1001 should be mounted in an upright position using the integral bracket and two #8 sheet metal screws (field furnished). The unit may be duct or panel mounted; refer to Fig. 13 for space requirements and additional mounting details. All pneumatic tubing connections should be made with 1/4 in O.D. polytubing. Application and Drawing Identification N-1001 Control Strategies Economizer Cycles The N-1001 offers a choice of either O.A. Dry Bulb, Differential Temperature, or Enthalpy Economizer cycles. Each of these methods uses different input measurements to determine which air stream (outside or return air) will impose the lightest load on the system cooling apparatus. Regardless of the economizer method selected, the Summer mode of operation will cause the DPR output to go to minimum Fig. 1: N-1001 Economizer Logic Network position pressure, and the AUX output will be at 20 PSIG (140 kpa) in the Winter mode, the DPR output signal will be equal to the IN signal or the minimum position setting, whichever is greater. The AUX output will be less than 1 PSIG (7 kpa) in the Winter mode. When the O.A. Dry Bulb Economizer cycle is selected by positioning the economizer jumper from COM to DB (see Fig. 2), the N-1001 compares the O.A. temperature signal to the switchover point established on the switchover adjustment. When the O.A. temperature signal to the switchover point established on the switchover adjustment. When the O.A. temperature is above the switchover point, the N-1001 will operate the system in the Summer mode. When the O.A. temperature is at or below the switchover point, the N-1001 will operate the system in the Winter mode. When the Differential Temperature Economizer cycle is selected by positioning the economizer jumper from COM to DIFF (see Fig. 3), the N-1001 compares the temperatures of the 1989 Johnson Controls, Inc. 1 Part No , Rev. A Code No. LIT

2 O.A. and R.A. transmitters (both transmitters must have identical ranges). Energy studies have concluded that this type of economizer method yields energy savings that are nearly as attractive as the Enthalpy Economizer method. When the O.A. temperature is equal to or greater than the R.A. temperature, the N-1001 will operate the system in the Summer mode. When the O.A. temperature is less than the R.A. temperature, the system will be controlled in the Winter mode. In this application, the switchover adjustment may be used to establish a differential between O.A. and R.A. This feature effectively adds one or more Fahrenheit degrees to the actual O.A. temperature. This may be done to account for a higher latent heat content in the O.A. due to levels of relative humidity. For example: Differential Setting = 5F O.A. Temperature = 68 F R.A. Temperature = 72 F Resultant Mode = Summer Mode Specifications For recommendations on the exact differential setting for a specific type of system in a specific geographical area, please consult the nearest Johnson Controls branch office. When the Enthalpy Economizer cycle is selected by positioning the economizer jumper from COM to DB (see Fig. 2), the N-1001 works in conjunction with an N-9000 Enthalpy Logic Center to execute the economizer cycle. Refer to Product Data N-9000 for more details. Fan Interlock The N-1001 interlocks the DPR and CLG output signals with the FAN status input signal. When the fan is ON, the FAN signal is at 20 PSIG (140 kpa) and the DPR and CLG signals are passed along to their respective controlled devices. When the fan is OFF, the FAN signal is at 1 PSIG (7 kpa) or less, and the DPR and CLG signals are at 0 PSIG (0 kpa), allowing their respective controlled devices to fail to their normal (closed) positions. The FAN connection provides a restricted source of supply air; therefore, no external source of supply air is required if a low volume fan status sensor is used (see Fig. 4). Other Control Strategies The TLL connection may be used for mixed air low limit control of the O.A. dampers or morning warmup interlock of the O.A. dampers, or both. In any 2 N-1001 Product Bulletin

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4 case, the TLL connection provides a restricted source of supply air to the low volume device that may be connected to it. If neither mixed air low limit or morning warmup features are required, the TLL connection MUST BE CAPPED. When TLL is used for Mixed Air Low Limit control of O.A. dampers (see Fig. 5), a proportional mixed air low volume thermostat, such as a T-3610, should be connected to the TLL connection. When the mixed air temperature drops below the low limit set point, the N-1001 will override the IN signal and may reduce the minimum position pressure to allow the O.A. dampers to modulate completely closed. Note: This mixed air low limit feature DOES NOT achieve coil freeze-up protection. When TLL is used for Morning Warmup control purposes (see Fig. 6), a direct acting two position R.A. sensor should be connected to the TLL connection. In this application, the N-1001 will keep the O.A. dampers completely closed until the morning warmup temperature is reached in the return air. At this time, minimum O.A. damper position will be restored by the N Manual override of the economizer cycle can be achieved by adding a three position selector switch, such as an S-2300, to the economizer selection jumper (see Fig. 7). Application/Operation Tips 1. There is an inherent delay of about five seconds in switchover from Winter mode to Summer mode. 2. On fan shutdown, the dampers and cooling apparatus return to their normal position; however, the AUX switchline remains unchanged. 4 N-1001 Product Bulletin 3. Control of the cooling apparatus may be altered externally to provide sequencing and/or cooling lockout. 4. All inputs, with the exception of the supply input, are deadended. This means that all input signals may be high volume (relay) or low volume (non-relay) type signals. 5. The N-1001 provides a.007 in. restricted source of supply pressure to the FAN and TLL input devices. No external source of restricted supply air is necessary to those input devices. 6. All outputs from the N-1001 are low volume. The volume of these outputs may be increased if necessary using a pilot positioner or an R-2080 Booster Relay.

5 7. The N-1001 may be used as a unit replacement for the N-1000 Logic Network. Note: The N-1001 does not provide a restricted source of supply air to the O.A. transmitter or thermostat; therefore, when replacing an N-1000 with a N-1001, an external source of supply air must be added to the O.A. transmitter or thermostat. Fig. 7 N-1001 Product Bulletin 5

6 EXAMPLE #1 Single Path Mixed Air with DX Cooling Room Control Economizer Switchover By Two-Position Thermostat Features Single Zone control Proportional control for operation of dampers and heating coil Two stages of DX cooling Inoperative dampers and cooling when fan is OFF 57 F low limit mixed air protection Return of O.A. dampers to minimum value at predetermined O.A. economizer dry bulb temperature Description of Operation The typical application illustrated in Fig. 8 shows the proportional output signal of TC-1 entering the IN connection of the N-1001 and being repeated to the DPR and CLG output, causing proportional operation of the O.A., R.A., and EXH.A. dampers and two-position operation of the cooling apparatus respectively. This is in sequence with the N.O. heating coil valve which is externally connected directly to TC-1. The DPR and CLG outputs modulate when the FAN signal is activated, and return to their normal positions when the FAN signal is deactivated. The low limit thermostat TLL-1 overrides the controller IN signal via an internal low signal selector, causing the O.A. dampers to modulate toward their closed position (beyond the minimum position signal if required) as the temperature at the TLL-1 element goes below its set point value. TS-1, which is connected to the O.A. input, has its element located in the outside air and has an adjustable switchover point. With the outside air temperature below the adjustable switchover setting, the O.A., R.A., and EXH.A. dampers modulate with the signal from TC-1 (Winter mode). When the outside air temperature rises above the setting, the O.A. dampers will close to their minimum position as established by the minimum position adjustment (Summer mode). 6 N-1001 Product Bulletin

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8 EXAMPLE #2 Single Path Mixed Air and Chilled Water Air Handling Unit Room Control - Multiple Zones Economizer Switchover By Ideal Dry Bulb Features Room control of unit via warmest zone Proportional operation of dampers and cooling coil valve in sequence Inoperative dampers and cooling when fan is OFF Low limit mixed air protection Return of O.A. dampers to minimum value when O.A. temperature plus its differential is greater than R.A. temperature. O.A. dampers automatically remain closed during morning warmup cycle Description of Operation The typical application illustrated in Fig. 9 shows the proportional output signal of TC-1, as the highest selected signal through PHLS-1, entering the IN connection of the N The TC-1 signal is repeated to the DPR and CLG outputs, causing proportional operation of the O.A., R.A., and EXH.A. dampers and cooling apparatus. These outputs modulate when the FAN signal is activated (20 PSIG), and return to their normal positions when the FAN signal is deactivated (1 PSIG or less). The low limit thermostat TLL-1 overrides the controller IN signal via an internal low signal selector, causing the O.A. dampers to modulate toward their closed position (beyond the minimum position signal if required) as the temperature at the TLL-1 element goes below its set point value. Transmitters TT-1 and TT-2 are connected to inputs O.A. and R.A. respectively, and the differential temperature of these transmitters is adjusted at the N An adjustable differential can be set at the N When the sum of the O.A. temperature plus its differential is less than the R.A. temperature, the O.A., R.A., and EXH.A. dampers will modulate with the highest signal selected by PHLS-1 (Winter mode). When the sum of the O.A. temperature plus its differential is greater than the R.A. temperature, the O.A. dampers will close to their minimum position as established by the minimum position adjustment (Summer mode). During morning warmup, the temperature at TT-2 is below the setting of PQ-1 and PQ-1 exhausts input signal TLL-1 to the atmosphere, causing the O.A. dampers to remain closed. When morning warmup is accomplished and TT-2 temperature has increased to the setting on PQ-1, the O.A. dampers operate as required by TC-1. 8 N-1001 Product Bulletin

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10 EXAMPLE #3 Single Path Mixed Air and Chilled Water Air Handling Unit Room Discharge Control Economizer Switchover By Dry Bulb Temperature Transmitter in Outside Air Perimeter Heating and Cooling Units Features Discharge air reset via room discharge control Proportional operation of dampers and cooling coil valve in sequence Inoperative dampers and cooling when fan is OFF Return of O.A. dampers to minimum value at predetermined O.A. dry bulb temperature Manual override of Summer/Winter switchover No switchover to Summer mode if no cooling available Low limit mixed air protection Summer/Winter switchover of heating-cooling thermostats via auxiliary switchline Description of Operation The typical application illustrated in Fig. 10 shows the proportional output signal of TC-1 entering the IN connection of the N The TRC-1 signal is repeated to the DPR and CLG outputs, causing proportional operation of the O.A., R.A., and EXH.A. dampers and cooling apparatus. These outputs modulate when the FAN signal is activated (20 PSIG), and return to their normal positions when the FAN signal is deactivated (1 PSIG or less). The Low limit thermostat TLL-1 overrides the controller IN signal via an internal low signal selector, causing the outside air dampers to modulate toward their closed position (beyond the minimum position signal if required) as the temperature at the TLL-1 element goes below its set point value. The transmitter TT-1 is connected to input O.A. and the dry bulb switchover temperature is adjusted at the N With the outside air temperature below the switchover setting, the O.A., R.A., and EXH.A. dampers modulate with the signal from TC-1 (Winter mode). When the outside air temperature rises above the switchover setting, the O.A. dampers will close to their minimum position as established by the minimum position adjustment (Summer mode). Additional functions of the system: 1. Manual override of the economizer mode is accomplished by the panel mounted switch PSM The TS-1 sensing the chilled water prevents the switchover of the unit to the Summer mode if no chilled water is available. 3. The AUX output (1 PSIG Winter, 20 PSIG Summer) switches the ASV-1 to change the room thermostats from the Winter heating mode to the Summer cooling mode. 10 N-1001 Product Bulletin

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12 EXAMPLE #4 Single Path Mixed Air and Chilled Water Air Handling Unit Proportional Plus Integral Discharge Air Temperature Control Enthalpy Switchover Features Proportional plus integral operation of dampers in sequence with cooling coil valve Inoperative dampers and cooling when fan is OFF Return of O.A. dampers to minimum value at proper enthalpy via N-9000 Enthalpy switchover of other similar systems Description of Operation The typical application illustrated in Fig. 11 shows the proportional plus integral output signal of TRC- 1 entering the IN connection of the N The TRC-1 signal is repeated to the DPR and CLG outputs, causing proportional plus integral operation of the O.A., R.A., and EXH.A. dampers and cooling apparatus. These outputs modulate when the FAN signal is activated, and return to their normal positions when the FAN signal is deactivated. The N-9000 Enthalpy Logic Center output is connected to the O.A. input and when its output is at 0 PSIG (0 kpa), the O.A., R.A., and EXH.A. dampers modulate with the signal from the TRC-1 (Winter mode). When the output signal of the N-9000 is at maximum, the O.A. dampers will close to their minimum position, as established by the minimum position adjustment (Summer mode). 12 N-1001 Product Bulletin

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14 Fig. 12: N-1001 Adjustment Points and Hypodermic Needle Test Points Set Point Adjustments (See Fig. 12) Adjusting screws are provided for field adjustment of: (1) the economizer switchover point, which is factory set in the differential economizer switchover mode at approximately 0.1 PSI (0.7 kpa) differential, and (2) the minimum position O.A. damper setting, which is factory set at approximately 9 PSIG (63 kpa). Economizer Switchover Point Adjustment (See Fig. 12) Differential Adjustment (if other than the factory setting) Note: Contact the local Johnson Controls branch office to determine the required differential for any given system. Jumper Position: COM to DIFF. Apply input pressure values from matched O.A. and R.A. temperature transmitters (T-5210s) to their respective connections. (This may be simulated by using a JC 5383 Calibration Kit, ordered separately.) The outside transmitter must be the lowest of the two inputs, separated by the required differential pressure. See the Differential Temperature Economizer example on page 2. Insert a hypodermic needle test probe (JC 5361, ordered separately) with a 0 to 30 PSIG test gage into the test point fitting of the AUX connection. The AUX output will be less than 1 PSIG (7 kpa) when the economizer switchover adjustment screw is set at minimum differential. Rotate the adjustment screw clockwise by small increments (allowing for a five second delay) until the AUX output increases. Reverse the adjusting screw slightly to cause the AUX output to decrease back to zero again. Check the economizer switchover by varying the O.A. input to cause the AUX output to switch from 0 PSIG (0 kpa) to 20 PSIG (140 kpa) and back again at the required differential. O.A. Dry Bulb Adjustment Jumper Position: COM to DB. Disconnect the jumper from the DB side and install a tube from DB side and install a tube from DB to a T-5500 Temperature indicator or a multirange transmission gage. The range chosen must match that of the O.A. transmitter (T-5210) used in the application. With the O.A. input connection (as labeled for dry bulb application) vented to atmosphere, adjust the economizer switchover adjustment screw to cause the desired O.A. input connection (as labeled for dry bulb application) vented to atmosphere, adjust the economizer switchover adjustment screw to cause the desired O.A. switchover temperature to be read on the gage. Disconnect the tube and gage and reconnect the jumper from COM to DB. Insert a hypodermic needle test probe (JC 5361, ordered separately) 14 N-1001 Product Bulletin

15 with a 0 to 30 PSIG test gage into the test point fitting of the AUX connection. Check the economizer switchover by varying the O.A. input to cause the AUX output to switch from 0 PSIG (0 kpa) to 20 PSIG (140 kpa) and back again at the desired temperature. (This may be simulated by using a JC 5383 Calibration Kit, ordered separately.) Reconnect the proportional O.A. transmitter (T-5210) to the proper O.A. input connection. Two-Position Input (A40 or N-9000) Jumper Position: COM to DB. Disconnect the jumper from the DB side and install a tube from DB to a 0 to 30 PSIG gage. With the O.A. input connection (as labeled for dry bulb application) vented to the atmosphere, adjust the economizer switchover adjustment screw to produce 5 PSIG (35 kpa) on the 0 to 30 PSIG gage. Disconnect the tube and gage and reconnect the jumper from COM to DB. Reconnect the two-position device to the proper O.A. input connection. Any temperature switchover adjustment must be made on the two-position device where applicable. Minimum Position O.A. Adjustment To accomplish minimum position O.A. damper adjustment, the following conditions must exist: 1. The FAN input must be at its ON value (20 PSIG). 2. The TLL input must be at its maximum value or be capped. After reducing the controller signal to the IN connection to its lowest value, insert a hypodermic needle test probe (JC 5361, ordered separately) with a 0 to 30 PSIG gage into the test point fitting for the DPR connection. The gage will indicate the minimum position O.A. setting. This setting may be changed from its factory setting of 9 PSIG (63 kpa) by turning the minimum position O.A. adjustment screw to the desired minimum pressure value. Note: An accurate 0 to 30 PSIG gage must be used and time must be allowed for the reading to stabilize. Repair Information Field repairs must not be made. For a replacement N-1001, contact the nearest Johnson Controls branch office. Replacement oil indicating filters are available, order A Dimension Drawing on Next Page -- N-1001 Product Bulletin 15

16 European Single Point of Contact: NA/SA Single Point of Contact: APAC Single Point of Contact: JOHNSON CONTROLS WESTENDHOF ESSEN GERMANY JOHNSON CONTROLS 507 E MICHIGAN ST MILWAUKEE WI USA JOHNSON CONTROLS C/O CONTROLS PRODUCT MANAGEMENT NO. 22 BLOCK D NEW DISTRICT WUXI JIANGSU PROVINCE CHINA Controls Group 507 E. Michigan Street P.O. Box 423 Milwaukee, WI Printed in U.S.A. 16 N-1001 Product Bulletin