G821L/G822L Series Integrated Function Direct Spark Ignition Controls

Transcription

1 Installation Sheets Manual 121 Gas Combustion Combination Controls and Systems Section G Technical Bulletin G821L/G822L Issue Date 1199 G821L/G822L Series Integrated Function Direct Spark Ignition Controls Figure 1: G821L/G822L Integrated Function Direct Spark Ignition Control Description The CE compliant G821L/G822L is a microprocessor-based, 100% shutoff, direct spark, and remote flame sense, integrated function ignition control. The control responds to inputs from the thermostat, high limit switch, rollout sensor, pressure switch, and flame sensor. It provides outputs for timing and sequencing of the main gas valve, induced draft motor, circulator/blower, and spark igniter. The G821L/G822L utilizes quick-connect terminals for all off board connections, except thermostat inputs and spark output. The thermostat inputs are connected to a terminal strip with screw terminals and the spark output is connected by a rajah, spike, or 6.35 mm (1/4 in.) male tab-type spark connector. The G821L control is a heating only integrated ignition control, and the G822L control is a heating and cooling integrated ignition control Johnson Controls, Inc. 1 Part , Rev. Code. LIT

2 Table 1: Specifications Ignition Type Ignition Source Direct Spark High voltage spark, capacitive discharge High Voltage Cable Wire: Stranded Insulation: Minimum Insulation Temperature Rating: Termination: Maximum Cable Length: Flame Sense Cable Wire: Stranded Flame Detection Means Flame Detection Types Minimum Flame Current Flame Threshold Current (I TH) Insufficient Flame Marginal Flame Good Flame Flame Failure Response Time Spark Gap Ignition Retrials 4 Safety Time Prepurge Time Postpurge Time Purge Time Loss of Flame Signal Retrials Circulator/Blower Times Power Requirements Contact Rating Minimum Insulation Temperature Rating: Maximum Cable Length: Flame rectification Remote sensing microampere microampere ± 25% Flame current <I TH I TH < flame current <4 x I TH Flame current >4 x I TH 1 second maximum 3.17 mm (0.125 in.) nominal 11 seconds* 10 seconds* 45 seconds* 10 seconds* 4 (five total ignition attempts) On Delay 30 seconds* Line Voltage: Control: Operation Current: Main Valve: Inducer: Blower: 25 kvdc minimum rating. 150 C (302 F) or suitable for the application, whichever is higher. Appropriately insulated connector to mate with the chosen transformer option. 1,220 mm (48 in.) 150 C (302 F) or suitable for the application, whichever is higher. 1,220 mm (48 in.) Off Delay 90, 120, 180, or 240 seconds heating* 45 seconds cooling* 120/230 VAC, 50 Hz 24 VAC, 50 Hz, nominal 24 VAC 2A 24 VAC, 5A inrush 1A continuous, 240 VAC 3/4 hp, 5A continuous, 15A inrush, 240 VAC External Power Transformer Kema Keur certified to EN Secondary voltage 24 VAC nominal, 50 Hz Ambient Operating and Storage -40 to 70 C (-40 to 160 F) Temperature Humidity 95% RH non-condensing Wiring Connections Spark Options: Spike, Rajah, or 6.35 mm (1/4 in.) male spade Types of Gas Natural, Liquefied Petroleum (LP), manufactured, mixed, or LP gas-air mixture Continued on next page... *Timings listed are for 50 Hz operation. 2 G G821L/G822L Series Integrated Function Direct Spark Ignition Controls Technical Bulletin

3 Specifications (Cont.) Packaging Bulk pack supplied to original equipment manufacturer (individual pack optional). Bulk Pack Quantity 24 Bulk Pack Weight Agency Listing 8 kg (18 lb) EC Certification Number E3731 Specification Standards EN 298 Standards Complying with the EMC Directive Classification Code FMCVXN Enclosure Degree of Protection IP00 The performance specifications are nominal and conform to acceptable industry standards. For application at conditions beyond these specifications, consult the local Johnson Controls office. Johnson Controls, Inc. shall not be liable for damages resulting from misapplication or misuse of its products. G G821L/G822L Series Integrated Function Direct Spark Ignition Controls Technical Bulletin 3

4 Application Requirements Operating Mode Definitions Following are the application requirements of the G821L/G822L control. The G821L/G822L can be used on gas-fired equipment with a maximum firing rate of 117 kw (400,000 Btu/hr). Any applications greater than 117 kw (400,000 Btu/hr) must have written approval in advance from the Heating Products Engineering Department. All G821L/G822L applications must use a redundant gas valve system with the main valve seats in series. The pressure switch must carry main valve current for redundancy. All G821L/G822L controls have volatile lockout. The following definitions describe operating conditions: Start Signal--The signal from a thermostat that begins the ignition program. Purge--The forced introduction of air through the combustion chamber and flue passages to displace any unburned gas and/or products of combustion. Prepurge--The purge that takes place between the start signal and the energization of the gas valve and ignition device. Prepurge Time--The period during which purge occurs at the proven air rate prior to the energization of the gas valve and ignition device. Safety Time--The time between energizing the main gas valve and de-energizing the main gas valve if the flame signal is not detected. Running Position--The main valve remains energized and the spark is de-energized. The appliance is in normal operation under the supervision of the ignition control and its flame detector device. Retrial--Failing an ignition attempt, the control enters a purge period and than starts another safety time. Recycling--The process of automatically repeating a startup sequence, (beginning with prepurge), after a safety shutdown (removing the power to the gas valve and igniter). Startup Sequence--The sequence of actions executed by the system that brings the burner from the start to the running position. Circulator/Blower On Delay --Fixed time delay after the flame signal is sensed until the circulator/blower is energized. Circulator/Blower Off Delay --Field selectable time delay after the thermostat contacts open when the circulator/blower remains energized. Postpurge--Time delay after successful running position period when the inducer remains energized. Volatile Lockout--The safety shutdown of the system where a startup sequence can only begin after the main power is cycled. 4 G G821L/G822L Series Integrated Function Direct Spark Ignition Controls Technical Bulletin

5 rmal Sequence of Operation Call for Heat Call for Cool Call for Manual Fan Figure 2 illustrates the sequence of operation of the G821L/G822L control. The G821L/G822L control is energized upon receiving a start signal from the system thermostat. 1. Pressure Switch Detection--The control checks the inducer pressure switch to ensure that it is open. 2. Prepurge--The control energizes the inducer motor and verifies that the pressure switch closes. The control delays for the prepurge time before continuing to the safety time. 3. Safety Time--The control simultaneously energizes the spark igniter and gas valve in an attempt to light the main burner. During the safety time, the igniter is energized until a flame signal is detected or until the safety time is complete, whichever occurs first. 4. Running Position--If main burner flame is sensed anytime during the safety time, the gas valve and inducer remain energized for the duration of the start signal. The circulator/blower is energized after the blower on delay time and remains energized for the duration of the heat call. 5. Postpurge--Once the start signal is removed, the gas valve is de-energized and the inducer remains energized until the postpurge period ends. The circulator/blower remains energized until the selected blower off delay time has elapsed. Upon receiving a start signal for cool from the system thermostat, the control energizes the blower motor at cooling speed. Once the signal is removed, the control waits for the cool fan off delay to expire before de-energizing the blower motor. Upon receiving a start signal for continuous manual fan, the control energizes the circulator/blower motor at heating fan speed. The continuous fan on request is immediately overridden by a signal for heat. G G821L/G822L Series Integrated Function Direct Spark Ignition Controls Technical Bulletin 5

6 Start signal for cool Start Start signal for manual fan (G) Flame present when not expected Run - manual fan speed Detected Fault Run - Cool fan speed Start signal for heat Flame signal present for 10 seconds? Volatile Lockout (LED will blink with a flash code of 5) Thermostat satisfied? Cool fan blower off delay Pressure switch open? Inducer on Volatile lockout! WARNING: Personal Injury Hazard. Avoid personal injury. The ignition control has volatile lockout. The control restarts operation if the main power is cycled. End Pressure switch closed? Prepurge Maximum number of retrials attemped? Safety time Fifth loss of flame signal? Flame signal sensed? Cirulator/Blower on delay Running position Loss of flame signal? Purge Thermostat satisfied? Postpurge Circulator/Blower off delay End Figure 2: G821L/G822L Sequence of Operation 6 G G821L/G822L Series Integrated Function Direct Spark Ignition Controls Technical Bulletin

7 Abnormal System Operation Pressure Switch Detection Undesired Flame The G821L/G822L offers the following responses based on abnormal system operation. A pressure switch within the appliance provides proof of combustion air flow. During a heating cycle, the control responds to the state of this switch in the following ways: At the beginning of the start signal, if the pressure switch is not open before the inducer is energized, the control will wait for the switch to open for as long as the heat start signal is present. The Light-Emitting Diode (LED) will blink with a flash code of 3 while waiting for the pressure switch to open. If the pressure switch does not close after the inducer has been energized for 5 seconds, the control will keep the inducer energized and the LED will blink with a flash code of 3 until the pressure switch closes or the heat start signal is removed. If the pressure switch opens any time after the control has begun the safety time, the control will immediately de-energize the gas valve. If the pressure switch fault occurs after the flame signal is sensed, the circulator/blower will run for 90 seconds, the inducer motor will remain energized, and the control will go into the Pressure Switch Open Fault state. During this time, the LED will blink with a flash code of 3. As long as the heat start signal is still present, the control will continue to wait for the pressure switch to close before resuming the heating cycle. If the pressure switch fails three times with no more than 30 seconds between successive faults, the control will de-energize all outputs, the LED will blink with a flash code of 3, and will remain in this state until the control power is recycled before returning to normal operation. If the flame signal is present at power up or when it should not be, the control energizes the inducer and circulator/blower and allows the flame 10 seconds to extinguish. If the flame signal is removed within 10 seconds, the normal sequence of operation continues. If the flame signal is still present after 10 seconds, the control goes into volatile lockout. During the volatile lockout, the inducer motor and the circulator/blower remain energized and the main valve is de-energized. The LED flashes with a duty cycle of 1/2 second On, 1/2 second Off for five flashes with a longer Off time before repeating the series. The control remains in volatile lockout until the power is recycled. G G821L/G822L Series Integrated Function Direct Spark Ignition Controls Technical Bulletin 7

8 Failure to Sense Flame Signal within Safety Time Loss of Flame Signal Interrupted Thermostat High Limit Switch If a flame signal is not sensed by the end of the safety time, the gas valve is de-energized, the inducer remains energized throughout the 10-second purge period, and another safety time begins. If the flame signal is not sensed by the end of the maximum number of safety times, in any given start signal, the control enters volatile lockout. The control remains in volatile lockout until the power is recycled. If the main burner flame is established and then lost, the gas valve is de-energized and the inducer and circulator/blower run through the purge period. Once the purge period expires, the control initiates another safety time. After the fifth loss of flame signal in any given start signal, the control will go into volatile lockout. The control remains in volatile lockout until the power is recycled. The G821L/G822L offers the following responses to the two possible interrupted thermostat situations: If the start signal for heat is removed before flame is sensed, the control will de-energize all outputs and return to the Off state. If the start signal for heat is removed any time after flame is sensed, the gas valve and spark igniter (if energized) are de-energized, the inducer motor remains energized through the postpurge period, and the circulator/blower remains energized for the selected blower off delay time. The high limit switch is monitored whenever a start signal for heat is present. Any time the switch opens, the gas valve and igniter are de-energized, and the inducer and circulator/blower run continuously. When the switch is reset, the inducer and circulator/blower run for 180 seconds (the control LED will blink with a flash code of 4) before the control returns to normal operation. Whenever the high limit switch is open while the start signal for heat is present, the control LED will blink with a flash code of 4. IMPORTANT: The G821L/G822L ignition control does not respond to a high limit fault with non-volatile lockout. Therefore, a manually resettable high limit switch must be used with this control to meet European agency operating requirements. 8 G G821L/G822L Series Integrated Function Direct Spark Ignition Controls Technical Bulletin

9 Control Timings Figure 3 illustrates the control s timings. rmal Heating Cycle LNE P T P1 T S T BON T R T P3 T BOFF Multiple Trials LNE P T BON T BOFF T P1 T S T P2 T S T R T P3 Loss of Flame Signal LNE P T BON T BOFF T P1 T S T R T P2 T S T R T P3 LNE P - Power - Thermostat - Inducer - Pressure Switch - Gas Valve - Spark Ignition - Main Blower Legend T P1 T S T BON T R T P2 T BOFF T P3 - Prepurge Time - Safety Time - Blower On-delay Time (Warm Up) - Running Position Time - Interpurge Time - Blower Off-delay Time (Cool Down) - Postpurge Time Figure 3: Timing Charts G G821L/G822L Series Integrated Function Direct Spark Ignition Controls Technical Bulletin 9

10 Installation and Wiring IMPORTANT: This technical bulletin is intended as a guide for qualified personnel installing or servicing Johnson Controls products. Carefully follow all instructions in this bulletin and all instruction on the appliance. Limit repairs, adjustments, and servicing to the operations listed in this bulletin or on the appliance.! WARNING: Fire or Explosion Hazard. Avoid serious injury by carefully following precautions in this bulletin and all instructions on the appliance. Limit repairs, adjustments, and servicing to the operations listed in this bulletin or on the appliance.! WARNING: Fire or Explosion Hazard. If the control is installed in an area that is exposed to water (dripping, spraying, rain, etc.), it must be protected. If the control has been exposed to water in any way, do not use it. Location and Mounting! WARNING: Shock Hazard. Avoid electrical shock and equipment damage. Disconnect the electrical power and turn off the gas before wiring the control into the circuit.! CAUTION: Equipment Damage Hazard. Do not mount the control where it will be exposed to direct infrared radiation from the main burner or to temperatures in excess of the maximum product temperature rating. Choose a location that provides the shortest, direct cable route to the spark igniter and flame sensor. Easy access to the terminals is desired for wiring and servicing. The control may be mounted in any position. Mount the control on a grounded metal surface with metal screws or bolts through the mounting holes provided on the control. 10 G G821L/G822L Series Integrated Function Direct Spark Ignition Controls Technical Bulletin

11 Electrical Connections! CAUTION: Equipment Damage Hazard. Connect the high voltage cable to the spark transformer terminal and spark igniter before applying power to the control. IMPORTANT: The G821L/G822L ignition control does not respond to a high limit fault with non-volatile lockout. Therefore, a manually resettable high limit switch must be used with this control to meet European agency operating requirements. Check the voltage rating marked on the control and ensure it is suited to the application. Use a transformer capable of providing 24 VAC under maximum load, including the valve. A transformer having excessive primary impedance due to poor coupling will affect the ignition potential. te: The transformer must be a safety insulating transformer tested to EN60742 or equivalent, and it must be installed and protected according to the manufacturer s specifications. Refer to Figure 4 for wiring diagram. All wiring should be in accordance with local codes and regulations. The high voltage spark transformer cable must not be in continuous contact with a metal surface. Use standoff insulators. Ensure that the flame sensor wire and high voltage spark transformer cable are separated from one another by a minimum distance of 6.35 mm (1/4 in.) and are not wrapped around any pipe, other wiring, or accessories. The thermostat wires must be cabled to prevent possible contact with a line voltage terminal. tes: This unit should be used only in applications that are within the limitations and provisions of the applicable European Union standards. These designs are tested to EN 298 Automatic Ignition Systems standards. Circulator/Blower Off Delay The circulator/blower off delay for heating is field selectable. To set the desired off delay, position the switches on Switch Block 1 (SW1) as presented in Table 2. (Refer to Figure 4 for SW1 location.) Table 2: Circulator/Blower Off Delay Switch Positions 1 2 Delay Off Off 90 seconds Off On 120 seconds On Off 180 seconds On On 240 seconds G G821L/G822L Series Integrated Function Direct Spark Ignition Controls Technical Bulletin 11

12 Sensor Pressure Switch High Limit Switch Rollout Switch 24 VAC Hot Ground Flame Sense PSW High Limit In High Limit Out Rollout In Valve Spark Transformer ACB Heat CMB Blower Line VAC Hot 4.76 mm (3/16 in.) Terminal Blower Off Delay Setting W G R te: All terminals are 6.35 mm (1/4 in.) unless otherwise specified. Pressure switch must carry main valve current for redundancy. Thermostat Transformer 24 VAC Line Line L1 120 VAC or 230 VAC 24 VAC ACC 1 2 Flame Sense Spark Electrode O N 4.76 mm (3/16 in.) Terminal SW1 24 VAC Common L2 Line Neutral Redundant Main Valve Coils Circulator/Blower Motor Inducer Motor IMPORTANT: The ignition control does not respond to a high limit fault with non-volatile lockout. Therfore, a manually resettable high limit switch must be used with this control to meet European agency operating requirements. 2.5 Ampere Fuse Figure 4: G821L/G822L Wiring Diagram 12 G G821L/G822L Series Integrated Function Direct Spark Ignition Controls Technical Bulletin

13 Checkout and Startup Procedures! WARNING: Fire or Explosion Hazard. Avoid personal injury or property damage by making sure the control functions properly and there are no gas leaks. Follow this checkout and startup procedure before leaving the installation. Make sure all components function properly by performing the following shutoff test: 1. With the gas and thermostat off, turn on power to the appliance. 2. Turn on the thermostat to the highest setting and verify that the control goes through the operating sequence to a shutoff condition. te: The burner will not light because the gas is off. 3. Turn off the thermostat. 4. Turn on the gas and purge gas lines of all air. 5. Check for gas leaks on all pipe joints upstream of the gas valve with a soap solution. 6. Turn on the thermostat to the highest setting and verify successful ignition and a normal running position for at least three minutes. 7. Check for gas leaks on all pipe joints downstream of the gas valve with a soap solution. 8. Turn the thermostat down for at least 30 seconds, and then back up again. Verify successful ignition at least three times. te: The control will complete the blower off delay (90, 120, 180, or 240 seconds) before initiating another heating cycle. 9. Return the thermostat to a normal temperature setting before leaving the installation. G G821L/G822L Series Integrated Function Direct Spark Ignition Controls Technical Bulletin 13

14 Thermostat Heat Anticipator Settings The thermostat anticipator setting is normally equal to the ignition system current draw, plus that of the main valve. Due to variations in appliance wiring and valves, it is advisable to measure the actual current draw of the heating system at the thermostat location. Measuring this current can be accomplished by opening the thermostat contacts (lowering the setpoint) and installing an AC ammeter across the terminals, or by using a clamp-on ammeter with a 10-turn multiplier attached to the terminals. See Figure 5. IMPORTANT: Measuring the current with an ammeter will energize the system. Wait until the appliance is in the running position before taking a current draw measurement. To Heating System W R AC Ammeter Low Scale Setting To Heating System W R Ten Turns Clamp-on Ammeter (Divide reading by ten.) Figure 5: Measuring the Thermostat Current 14 G G821L/G822L Series Integrated Function Direct Spark Ignition Controls Technical Bulletin

15 Service Procedures If the system does not function properly, check the following: Are all mechanical and electrical connections tight? Is the system wired correctly? Is gas inlet pressure per manufacturer s specifications? Is the system powered? Is there a start signal for heat from the thermostat? Flash Codes Table 3: LED Flash Code Summary Flash Code Flash Code Description Slow Flash Fast Flash Flash Three Flash Four Flash Five Steady On rmal operation, no call for heat rmal operation, call for heat Pressure switch open or closed fault High limit or rollout switch open Flame sensed when not expected Internal failure (microcontroller self-check failure) Repairs and Replacement! CAUTION: Equipment Damage Hazard. Label all wires prior to disconnection when servicing controls. Wiring errors can cause improper and dangerous operation. The G821L/G822L controls are not field repairable. Do not attempt field repairs to the ignition control. Use only an exact or recommended replacement control. For a replacement control or accessories, contact the original equipment manufacturer or the nearest Johnson Control distributor. G G821L/G822L Series Integrated Function Direct Spark Ignition Controls Technical Bulletin 15

16 tes Controls Group E. Michigan Street FAN 121 P.O. Box 423 Installation Sheets Manual Milwaukee, WI Printed in U.S.A. 16 G G821L/G822L Series Integrated Function Direct Spark Ignition Controls Technical Bulletin