G670 Intermittent Pilot Ignition Controls

Transcription

1 Installation Sheets Manual 121 Gas Combustion Combination Controls and Systems Section G Technical Bulletin Issue Date 0300 Intermittent Pilot Ignition Controls Figure 1: Intermittent Pilot Ignition Control Description Application Requirements The is a n-100% Lockout Intermittent Pilot Ignition (IPI) control that replaces the G67AG and G67BG ignition controls. The is used to automatically light a pilot burner and energize the main burner gas valve in response to a call for heat from the system thermostat. When the call for heat is satisfied, the thermostat opens and the de-energizes the pilot and main burner gas valves. Following are the application requirements of the control. The can be used with equipment with a maximum firing rate of 117 kw (400,000 Btu/hr). Any application greater than 117 kw (400,000 Btu/hr) must have written approval in advance from the Heating Products Engineering Department. All applications must use a redundant gas valve system with the main valve seats in series Johnson Controls, Inc. 1 Part , Rev. B Code. LIT

2 Table 1: Specifications Ignition Type Ignition Source High Voltage Cable Length Flame Detection Means Flame Detection Types Minimum Flame Current Flame Failure Response Time Spark Gap Ignition Trial Time Indirect High voltage spark, capacitive discharge 915 mm (36 in.) maximum Flame rectification Remote sensing 0.2 microampere 0.8 second, maximum 2.5 mm (0.1 in.) nominal Infinite Power Requirements Control: 24 VAC, 50/60 Hz, nominal Operation Current: 0.15A nominal + valves Contact Rating Main Valve: 2A continuous, 5A inrush Pilot Valve: 2A continuous, 5A inrush Ambient Operating and -40 to 66 C (-40 to 150 F) Storage Temperature Humidity 95% RH non-condensing Types of Gas Natural (Liquefied Petroleum [LP], manufactured, mixed, or LP gas-air mixture may be used in a well vented or outdoor application.) Agency Listing CSA (AGA/CGA) Certificate Number Specification Standards ANSI Standard Z21.20 CSA C 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. Operating Mode Definitions The following definitions describe operating conditions. Trial for Ignition--Period during which the pilot valve and spark are activated attempting to ignite gas at the main burner. The trial-for-ignition period is infinite for the s and ends once the pilot flame is detected or the call for heat ends. Run--The main valve remains energized and the spark is turned off after successful ignition. Flameout--Loss of proven flame. Should a flameout occur, the main valve closes and the spark recurs within 0.8 second. 2 G Intermittent Pilot Ignition Controls Technical Bulletin

3 Sequence of Operation Figure 2 illustrates the sequence of operation for the ignition control. On a call for heat from the system thermostat, the simultaneously opens the pilot valve and supplies a continuous spark to the pilot burner s electrode. When the pilot burner gas ignites, the pilot flame sensor detects the pilot flame and signals the to energize the main gas valve and discontinue the spark. The main gas valve will not be energized until the flame sensor detects the presence of the pilot flame. If the pilot flame goes out (with the thermostat still calling for heat), the will de-energize the main gas valve and provide a continuous spark at the pilot burner s electrode. When the pilot flame is re-ignited and detected by the pilot flame sensor, the main gas valve is energized and the spark is shut off. The de-energizes the pilot gas valve and main burner gas valve when the thermostat stops calling for heat. Start Thermostat Call for Heat Flame Present? Trial for Ignition Pilot Flame Sensed? Energize Main Valve Run Flameout? De-energize Main Valve Thermostat Calling for Heat? De-energize Control Pilot and Main Valves End Figure 2: Sequence of Operation G Intermittent Pilot Ignition Controls Technical Bulletin 3

4 Installation IMPORTANT: These instructions are intended as a guide for qualified personnel installing or servicing Johnson Controls ignition controls. Carefully follow all instructions 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. 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.! WARNING: Shock Hazard. Avoid electrical shock and equipment damage. Disconnect electrical power and turn off the gas before wiring the control.! CAUTION: Equipment Damage Hazard. Label all wires prior to disconnection when servicing controls. Wiring errors can cause improper and dangerous operation. Verify proper operation after servicing. Mounting Perform the following procedure to install the ignition control. 1. Shut off power to the appliance. 2. Turn off gas at the manual shutoff valve adjacent to the appliance. 3. Label each wire with the correct terminal designation prior to disconnection. 4. Disconnect the power supply (transformer) and the thermostat lead wire at the ignition control. 5. Disconnect the sensing probe lead from Terminal 4 on the ignition control. 6. Disconnect the high voltage cable from the spark transformer. 7. Disconnect the Pilot Valve 1 and Main Valve 3 leads from the ignition control. 8. Disconnect any wires connected to the ground terminals on the ignition control. 4 G Intermittent Pilot Ignition Controls Technical Bulletin

5 9. Remove the screws holding the ignition control assembly in place. 10. Remove the ignition control and discard. 11. Using the same holes as the old ignition, mount the new control on a grounded metal surface with metal screws or bolts through the mounting holes provided on the enclosure. Modifying Existing Ignition Cable All spark ignition controls have a spark transformer connected to a high voltage cable. There are three types of connection for the high voltage cable: Spike, Rajah, and 6.35 mm (1/4 in.) male spade (see Figure 3). The has a Spike transformer. When replacing a control that has a Rajah or male spade connection, the crimp-on connector must be cut off. 1. Slide the rubber boot up the cable. 2. Cut the lead just above the connector (see Figure 4). Make a straight cut perpendicular to the cable. 3. Center the exposed wire on the end of the lead over the spike in the spark transformer and push the wire lead down firmly over the spike (see Figure 5). 4. Ensure the lead is inserted all the way into the spark transformer. Slide the boot back down the cable and over the spark transformer. Spike Connection Rajah Connection 6.35 mm (1/4 in.) Male Spade Figure 3: High Voltage Cable Connectors High Voltage Cable Insulating Boot Crimp-on Connector Cut off connector here. Figure 4: High Voltage Cable with Crimp-On Connector High Voltage Cable Spike must be in contact with the center wires. Figure 5: Spark Transformer Connection G Intermittent Pilot Ignition Controls Technical Bulletin 5

6 Wiring! CAUTION: Equipment Damage Hazard. Connect the high voltage cable to the spark transformer terminal and spark electrode (pilot burner assembly) before applying power to the control. Ensure the ground wire is attached to the pilot burner and control ground terminal strip.! CAUTION: Equipment Damage Hazard. Locate all limit and operating controls in series with the thermostat terminal (THS 2) on the ignition control. Check the voltage rating marked on the control and make sure it is suited to the application. Use a National Electrical Code (NEC) Class 2 transformer to provide 24 VAC under maximum load, including valves. A transformer having excessive primary impedance due to poor coupling will affect the ignition potential. Refer to Figures 6 through 9 for wiring diagrams. All wiring should be in accordance with the NEC and all other 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 the 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. 6 G Intermittent Pilot Ignition Controls Technical Bulletin

7 Thermostat Limits in the Thermostat Line Only W R Y MV Jumper PV in 24 VAC Power Supply Pilot Burner Ground Ground Terminals Flame Sensor High Voltage Cable Figure 6: ment Wiring Diagram if the Original Control is a G67AG Thermostat W R Y Limits in the Thermostat Line Only MV PV Jumper 5 24 VAC Power Supply Pilot Burner Ground Ground Terminals Flame Sensor Install the jumper supplied with the replacement control between Terminals 2 and 6. High Voltage Cable Figure 7: ment Wiring Diagram if the Original Control is a G67BG G Intermittent Pilot Ignition Controls Technical Bulletin 7

8 Thermostat High Limits In This Line Only W R Y MV Y79 MV PV Power Supply 24 VAC PV Jumper 5 Brown White Pilot Burner Ground Black Flame Sensor Install the jumper supplied with the replacement control between Terminals 2 and 6. High Voltage Cable Figure 8: Wiring Diagram for with Y79B Thermostat W R Y Y79 THS High Limits In This Line Only MV PV Jumper 5 24 VAC White Power Supply Pilot Burner Ground Red Black Flame Sensor High Voltage Cable Figure 9: Wiring Diagram for with a Y79A 8 G Intermittent Pilot Ignition Controls Technical Bulletin

9 Checkout and Startup Procedure! 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.! WARNING: Fire or Explosion Hazard. Do not attempt to check out this system by manually lighting the pilot. This could energize the main valve. Make sure all components are functioning 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. Test for gas leaks on all pipe joints and connections 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 run condition for at least three minutes. If the appliance fails to run, see the Service Checkout Procedures section. 7. Test for leaks on all pipe joints and connections 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. 9. Return the thermostat to a normal temperature setting before leaving the installation. G Intermittent Pilot Ignition Controls Technical Bulletin 9

10 Thermostat Heat Anticipator Settings The thermostat anticipator setting is normally equal to the ignition system current draw, plus that of the pilot and 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 set point) 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 10). IMPORTANT: Measuring the current with an ammeter will energize the system. Wait until the gas valve and inducer energize 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 10: Measuring the Thermostat Current 10 G Intermittent Pilot Ignition Controls Technical Bulletin

11 Troubleshooting Procedure Preliminary Checks Failure Conditions and Corrective Action If the system does not function properly, determine the cause using the procedures in this section. Before proceeding with troubleshooting the system, check the following: Are all mechanical and electrical connections tight? Is the system wired correctly? Is the gas inlet pressure per the manufacturer s specifications? Is the system powered? Is the thermostat calling for heat? There are three potential system failure conditions: no spark, and system does not work spark is present, but pilot does not light pilot lights, but main valve does not come on Determine the failure condition, then use the respective flowcharts on the following pages to troubleshoot the system. Perform the procedures in the Checkout and Startup Procedure section after any servicing. Repairs and ment! CAUTION: Label all wires prior to disconnection when servicing controls. Wiring errors can cause improper and dangerous operation. Verify proper operation after servicing. Do not attempt field repairs. Use only exact or factory recommended replacement controls. All other accessories, such as flame sensors, electrode assemblies, pilot assemblies, and leads can be obtained through the original equipment manufacturer or a Johnson Controls distributor. G Intermittent Pilot Ignition Controls Technical Bulletin 11

12 Start Visually check. Is Lead 5 connected securely to ground? Connect securely Are thermostat and limit contacts closed? Is 24 VAC present between Terminal 2 and ground? Is 24 VAC present between Terminal 6 and ground? Close contacts Repair Is circuit wiring providing 24 VAC to Terminal 2? Is 24 VAC present between Terminal 1 and ground? Check for proper voltage at transformer primary and secondary te: In some instances a jumper is used between Terminals 2 and 6 to power Terminal 6. Is circuit wiring providing 24 VAC to Terminal 6? Repair Turn off supply voltage cable Is high voltage cable in good condition (not brittle, burnt, or cracked)? Is high voltage cable connected to spark transformer? Is spark gap 0.1 in. and located in pilot gas stream? Correct or replace pilot burner Is spark electrode ceramic cracked? pilot burner Connect securely Turn on supply voltage Turn on supply voltage Operate system several complete cycles End Figure 11: Spark, and System Does t Work 12 G Intermittent Pilot Ignition Controls Technical Bulletin

13 Start Is pilot valve wiring securely connected to Terminal 1 and ground? Connect securely Is 24 VAC present between Terminal 1 and ground?! WARNING: Explosion Hazard. Do not use a match to test for presence of gas. Is inlet gas pressure per manufacturer s specifications? Is gas at pilot? Make sure pilot line is not kinked or obstructed. Check for clean orifice. Correct gas pressure pilot valve Is pilot spark gap 0.1 in. and located in pilot gas stream? Correct or replace pilot Check for drafts. Shield as necessary and check for clean orifice. End Figure 12: Spark is Present, but Pilot Does t Light G Intermittent Pilot Ignition Controls Technical Bulletin 13

14 Start Does spark stay on for more than 30 seconds after the pilot lights? Is 24 VAC between Terminal 3 and ground? Is inlet gas pressure per manufacturer s specifications? Correct gas pressure Make sure sensor cable and high voltage cable are separated and not wrapped around any pipe or accessories. Is main valve wiring securely connected to Terminal 3 and ground? Connect securely Is sensor cable securely connected to Terminal 4 and flame sensor? Connect securely main valve Is sensor ceramic cracked? Is cable grounded out? Is sensor or sensor connector shorted out to metal surface? Correct sensor Correct Is there continuity and good insulation in the sensor cable? cable Connect DC microammeter between sensor cable terminal and Terminal 4. Observe correct polarity. See Figure 20. Disconnect sensor cable from Terminal 4 Disconnect main valve lead from Terminal 3 Is DC current 0.2 microamperes or greater with pilot only operation? Check for: - proper gas pressure - clean pilot assembly - tight mechanical and electrical connections If there is not improvement, change the flame sensor length or the orifice size and perform any necessary turn down tests. End Figure 13: Pilot Lights, but Main Burner Does t Come On 14 G Intermittent Pilot Ignition Controls Technical Bulletin

15 Start Is system wiring per manufacturer s instructions? Open thermostat contacts for 30 seconds Correct wiring Close thermostat contacts and wait 30% of the Y79 lockout time Is a spark present? System was in lockout Determine reason for lockout. Conduct microamperage test as outlined in Figure 16, starting at A. Is 24 VAC present between Terminal 2 and ground? Is 24 VAC present between Terminal 1 and ground? Turn off supply voltage Connect securely Check the high voltage cable. Is it securely connected to the spark transformer? Is 24 VAC present on secondary of transformer? Turn supply voltage on the transformer if proper voltage is present on primary of transformer. Is high limit closed? cable Is condition of high voltage cable good (not brittle, burnt, or cracked)? Reset high limit the Y79 with the appropriate G600 Ignition controls (contact Johnson Controls Technical Support). Is spark gap 0.1 in. and located in pilot gas stream? Correct or replace pilot burner Is spark electrode ceramic cracked? Turn supply voltage on pilot burner Operate system several complete cycles End Figure 14: /Y79B Spark, and System Does t Work G Intermittent Pilot Ignition Controls Technical Bulletin 15

16 Start Are pilot valve and main valve connections secured to the proper Y79 terminal and ground? Open thermostat contacts for 30 seconds Close thermostat contacts Connect securely Is 24 VAC present between ground and pilot valve terminals of Y79? Is 24 VAC present between Terminal 1 and ground on the? Wait 30% of the Y79 lockout time. the Y79 with the appropriate G600 ignition control (contact Johnson Controls Technical Support). Correct Is inlet pressure per manufacturer s specifications?! WARNING: Explosion Hazard. Do not use a match to test for presence of gas. Is gas at pilot? Is spark gap 0.1 in. and located in the pilot gas stream? Make sure the pilot line is not kinked or obstructed. Check for a clean orifice. Correct or replace pilot burner Check for drafts. Shield as necessary and check for clean orifice. If OK, replace pilot valve. End Figure 15: /Y79B Spark is Present, but Pilot Does t Light 16 G Intermittent Pilot Ignition Controls Technical Bulletin

17 Start Does spark stay on for more than 30 seconds after pilot lights? Is 24 VAC between Terminal 3 Is inlet gas pressure and ground? per manufacturer s specifications? Correct gas pressure Make sure sensor cable and high voltage cable are separated and not wrapped around any pipe or accessories. Is 24 VAC present between main valve terminal on the Y79 and ground terminal on the? Is sensor cable securely connected to Terminal 4 and flame sensor? Connect securely the Y79 with the appropriate G600 ignition control (contact Johnson Controls Technical Support). Is sensor ceramic cracked? Is main valve wiring securely connected to the main valve terminal on the Y79 and ground? Connect securely sensor Is cable grounded out? Is sensor or sensor connector shorted out to metal surface? Correct main valve Correct Is there continuity and good insulation in the sensor cable? cable Connect DC microammeter between sensor cable terminal and Terminal 4. Observe correct polarity. See Figure 20. Disconnect sensor cable from Terminal 4 Disconnect main valve lead from Terminal 3 A Is DC current 0.2 microamperes or greater with pilot only operation? Check for: - proper gas pressure - clean pilot assembly - tight mechanical and electrical connections If there is no improvement, change the flame sensor length or the orifice size, then perform any necessary turn down tests. End Figure 16: /Y79B Pilot Lights, but Main Burner Does t Come On G Intermittent Pilot Ignition Controls Technical Bulletin 17

18 Start Is system wiring per manufacturer s instructions? Open thermostat contact for 30 seconds Correct wiring Close thermostat contacts and wait 30% of the Y79 lockout time Is a spark present? Is 24 VAC present between Terminal 2 and ground? System was in lockout Is 24 VAC present between Terminal 1 and ground? Determine the reason for lockout. Conduct microamperage test as outlined in Figure 16, starting at A. Turn off supply voltage Is 24 VAC present on secondary of transformer? Connect securely Check the high voltage cable. Is it securely connected to the spark transformer? transformer if proper voltage is present on primary of transformer Reset high limit Is high limit closed? Turn supply voltage on cable Is condition of high voltage cable good (not brittle, burnt, or cracked)? the Y79 with the appropriate G600 ignition control (contact Johnson Controls Technical Support). Is spark gap 0.1 in. and located in pilot gas stream? Correct or replace pilot burner Is spark electrode ceramic cracked? pilot burner End Operate system several complete cycles Turn supply voltage on Figure 17: /Y79A Spark, and System Does t Work 18 G Intermittent Pilot Ignition Controls Technical Bulletin

19 Start Is pilot valve wiring securely connected to Terminal 1 and ground? Connect securely! WARNING: Explosion Hazard. Do not use a match to test for presence of gas. Is inlet gas pressure per manufacturer s specifications? Is gas at pilot? Make sure pilot line is not kinked or obstructed. Check for clean orifice. Correct gas pressure pilot valve Is pilot spark gap 0.1 in. and located in pilot gas stream? Correct or replace pilot Check for drafts. Shield as necessary and check for clean orifice. End Figure 18: /Y79A Spark is Present, but Pilot Will t Light G Intermittent Pilot Ignition Controls Technical Bulletin 19

20 Start Does spark stay on for more than 30 seconds after the pilot lights? Is 24 VAC between Terminal 3 and ground? Is inlet gas pressure per manufacturer s specifications? Correct gas pressure Make sure sensor cable and high voltage cable are separated and not wrapped around any pipe or accessories. Is main valve wiring securely connected to Terminal 3 and ground? Connect securely Is sensor cable securely connected to Terminal 4 and flame sensor? Connect securely main valve Is sensor ceramic cracked? Is cable grounded out? Is sensor or sensor connector shorted out to metal surface? Correct sensor Correct Is there continuity and good insulation in the sensor cable? cable Connect DC microammeter between sensor cable terminal and Terminal 4. Observe correct polarity. See Figure 20. Disconnect sensor cable from Terminal 4 Disconnect main valve lead from Terminal 3 Is DC current 0.2 microamperes or greater with pilot only operation? Check for: - proper gas pressure - clean pilot assembly - tight mechanical and electrical connections If there is not improvement, change the flame sensor length or the orifice size and perform any necessary turn down tests. End Figure 19: /Y79A Pilot Lights, but Main Burner Does t Come On 20 G Intermittent Pilot Ignition Controls Technical Bulletin

21 Y99AU-2 Multimeter Jumper 5 Electrode Pilot Burner Assembly Positive Lead to Terminal 4 Negative Lead to Flame Sensor Figure 20: Meter Hookup to Measure Flame Sensing Circuit G Intermittent Pilot Ignition Controls Technical Bulletin 21

22 tes 22 G Intermittent Pilot Ignition Controls Technical Bulletin

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24 tes Controls Group E. Michigan Street FAN 121 P.O. Box 423 Installation Sheets Manual Milwaukee, WI Printed in U.S.A. 24 G Intermittent Pilot Ignition Controls Technical Bulletin