Johnson Controls GGLS*MP, TGLS*MP, TG8S*MP, GG8S*MP installation manual Section IX Safety Controls

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356485-UIM-G-1211

SECTION IX: SAFETY CONTROLS

CONTROL CIRCUIT FUSE

A 3-amp fuse is provided on the control circuit board to protect the 24- volt transformer from overload caused by control circuit wiring errors. This is an ATO 3, automotive type fuse and is located on the control board.

BLOWER DOOR SAFETY SWITCH

Main power to the unit must still be interrupted at the main power disconnect switch before any service or repair work is to be done to the unit. Do not rely upon the interlock switch as a main power dis- connect.

Blower and burner must never be operated without the blower panel in place.

This unit is equipped with an electrical interlock switch mounted in the burner compartment. This switch interrupts all power at the unit when the panel covering the blower compartment is removed.

Electrical supply to this unit is dependent upon the panel that covers the blower compartment being in place and properly positioned.

ROLLOUT SWITCH CONTROLS

These controls are mounted on the burner assembly. If the temperature in the area surrounding the burner exceeds its set point, the gas valve is de-energized. The operation of this control indicates a malfunction in the combustion air blower, heat exchanger or a blocked vent pipe con- nection. Corrective action is required. These are manual reset controls that must be reset before operation can continue.

PRESSURE SWITCHES

This furnace is supplied with a pressure switch, which monitors the flow through the combustion air/vent piping system. This switch de-ener- gizes the gas valve if any of the following conditions are present.

1.Blockage of vent piping or terminal.

2.Failure of combustion air blower motor.

LIMIT CONTROLS

There is a high temperature limit control located on the furnace vesti- bule panel near the gas valve. This is an automatic reset control that provides over temperature protection due to reduced airflow. This may be caused by:

1.A dirty filter.

2.If the indoor fan motor should fail.

3.Too many supply or return registers closed or blocked off.

The control module will lockout if the limit trips 5 consecutive times. If this occurs, control will reset & try ignition again after 1 hour.

Heating Cycle

When the thermostat switch is set on HEAT and the fan is set on AUTO, and there is a call for heat, a circuit is completed between terminals R and W of the thermostat. When the proper amount of combustion air is being provided, the pressure switch will close, the ignition control pro- vides a 17-second ignitor warm-up period, the gas valve then opens, the gas starts to flow, ignition occurs and the flame sensor begins its sensing function. The blower motor will energize 30 seconds after the gas valve opens, if a flame is detected. Normal furnace operation will continue until the thermostat circuit between R and W is opened, which causes the ignition system and gas valve to de-energize and the burner flames to be extinguished. The vent motor will operate for 15 seconds and the blower motor will operate for the amount of time set by the fan- off delay jumper located on the control board. See Figure 27. The heat- ing cycle is now complete, and ready for the start of the next heating cycle.

If the flame is not detected within 7 seconds of the gas valve opening, the gas valve is shut off and a retry operation begins. Also, if the flame is lost for 2 seconds during the 10-second stabilization period, the gas valve is shut off and a retry operation begins. During a retry operation, the vent motor starts a 15 second inter-purge and the ignitor warm-up time is extended to 27 seconds. If the flame is established for more than 10 seconds after ignition during a retry, the control will clear the ignition attempt (retry) counter. If three retries occur during a call for heat, the furnace will shut down for one hour. If at the end of the one hour shut down there is a call for heat, the furnace will initiate a normal start cycle. If the problem has not been corrected the furnace will again lockout after three retries.

A momentary loss of gas supply, flame blowout, or a faulty flame probe circuit will result in a disruption in the flame and be sensed within 1.0 seconds. The gas valve will de-energize and the control will begin a recycle operation. A normal ignition sequence will begin after a 15 sec- ond inter-purge. If during the five recycles the gas supply does not return, or the fault condition is not corrected the ignition control will lock- out for 60 minutes.

During burner operation, a momentary loss of power for 50 milliseconds or longer will de-energize the gas valve. When the power is restored, the gas valve will remain de-energized and the ignition sequence will immediately restart.

Hot Surface Ignition System

HOT SURFACE IGNITION SYSTEM

Do not attempt to light this furnace by hand (with a match or any other means). There may be a potential shock hazard from the components of the hot surface ignition system. The furnace can only be lit automatically by its hot surface ignition system.

SEQUENCE OF OPERATION

The following describes the sequence of operation of the furnace. Refer to Owners Manual for component location.

Continuous Blower

Cooling/heating thermostats have a fan switch that has an ON and AUTO position. In the ON position the thermostat circuit is completed between terminals R and G. The motor will operate continuously on the speed tap wire that is connected to the “HI COOL” cooling terminal on the control board. To obtain a constant air circulation at lower flow rate, change the high-speed wire to either the medium speed wire or the low speed wire.

Intermittent Blower - Cooling

Cooling/heating thermostats have a fan switch that has an ON and AUTO position. In the AUTO position the thermostat circuit is completed between terminals R and G when there is a call for cooling. The motor will operate on the speed tap wire that is connected to the “HI COOL” cooling terminal on the control board. The fan off setting is fixed at 60 seconds to improve cooling efficiency.

TROUBLESHOOTING

The following visual checks should be made before troubleshooting:

1.Check to see that the power to the furnace and the ignition control module is ON.

2.The manual shut-off valves in the gas line to the furnace must be open.

3.Make sure all wiring connections are secure.

4.Review the sequence of operation. Start the system by setting the thermostat above the room temperature. Observe the system’s response. Then use the troubleshooting section in this manual to check the system’s operation.

Never bypass any safety control to allow furnace operation. To do so will allow furnace to operate under potentially hazardous condi- tions.

Do not try to repair controls. Replace defective controls with UPG Source 1 Parts.

Never adjust pressure switch to allow furnace operation.

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Johnson Controls Unitary Products

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Contents List of Figures Section I SafetyList of Sections List of TablesAnce to a 50 HZ Power Supply or a Voltage Above 130 Volts Specific Safety Rules and PrecautionsSafety Requirements Combustion AIR Quality List of Contaminants Codes and StandardsDirectly BELOW. Keep Clear of ALL OBSTRUC- Tions InspectionFurnace Location and Clearances Section II Ductwork Floor Base and Ductwork Installation DownflowCoil Installation Ductwork General InformationCoil Flange Installation COIL/FURNACE Assembly MC/FC/PC Series CoilsFurnace Assembly MC & FC Series Coils Furnace Assembly PC Series CoilsBottom Return and Attic Installations Coil / Furnace Assembly HC Series CoilsDownflow Duct Connectors Attic InstallationSuspended Furnace / Crawl Space Installation Typical Suspended Furnace / Crawl Space InstallationSection III Filters Filter InstallationAttempt to install filters inside the furnace Btuh kWSection IV GAS Piping GAS SafetyGAS Piping Installation Side ReturnHigh Altitude GAS Orifice Conversion High Altitude Pressure Switch ConversionGAS Orifice Conversion for Propane LP Manifold Pressures in wcLOW Voltage Control Wiring Connections Section V Electrical PowerElectrical Power Connections Supply Voltage ConnectionsSingle Stage PSC AIR Furnace Conditioner ID ModelsThermostat Single Stage Heat Pump Single Stage PSC FurnaceOD Models Section VI Twinning and Staging Vent Connections Section VII Vent SystemStaging Venting Into AN Existing Chimney Category 1 450 F. MAX. Vent TempVenting FAN-ASSISTED Combustion SystemVentilated Combustion Air Vent and Supply Outside Air Safety Check ProcedureAir Supply Openings and Ducts Free AreaSection Viii START-UP Adjustments NOx Screen Removal Lo-NOx Models OnlyCalculating the Furnace Input Natural GAS GAS Piping Leak CheckIgnition System Sequence Revolution Revolution Cu FtSeconds For Read the manifold gas pressure Adjustment of Manifold GAS Pressure & Input RateRead the inlet gas pressure Nominal Manifold PressureManifold Pressure U Tube Connection Adjustment of Temperature RiseAdjustment of FAN Control Settings Bottom Airflow Data Scfm 1086 971 843 521 060A10 Medium High 1249 1207 757 733 694 659 575 444 399707 684 641 604 495 397 282 High 1371 1323 1251 1098 1018 921 669 503Section IX Safety Controls Furnace Control Diagnostics Section X Replacement Parts List Diagnostic Fault Code Storage and RetrievalSection XI Wiring Diagram Wiring DiagramJohnson Controls Unitary Products York Drive Norman, OK

TG8S*MP, GG8S*MP, TGLS*MP, GGLS*MP specifications

Johnson Controls is a leader in the development of innovative building management solutions, and its product line encompassing the GGLS*MP, TGLS*MP, TG8S*MP, and GG8S*MP series exemplifies this commitment to excellence. These devices are designed to optimize energy efficiency, enhance occupant comfort, and ensure seamless integration into commercial building infrastructures.

The GGLS*MP series focuses on the integration of advanced sensors and controllers that facilitate effective lighting and HVAC management. With built-in capabilities for occupancy sensing and daylight harvesting, these devices can automatically adjust settings based on real-time conditions. Their energy-efficient operation not only contributes to lower utility costs but also supports sustainability goals, making them ideal for modern green buildings.

In contrast, the TGLS*MP series emphasizes the importance of temperature regulation and comfort in residential or smaller commercial settings. These controllers utilize advanced algorithms to maintain optimal indoor climates, adjusting heating and cooling outputs in response to ambient conditions. The intuitive user interface makes it easy for users to customize their settings, providing enhanced comfort without sacrificing energy efficiency.

The TG8S*MP series is particularly renowned for its robust communication features. These devices support multiple communication protocols, allowing them to integrate smoothly with existing building management systems. This versatility ensures that customers can leverage their current infrastructure while benefiting from new technology. Additionally, the TG8S*MP includes remote monitoring capabilities, enabling facility managers to track performance metrics and troubleshoot issues from anywhere.

Lastly, the GG8S*MP series brings together security and control features, ensuring that buildings are not only energy-efficient but also secure. With capabilities for access control and monitoring, these devices provide a comprehensive solution for managing facility safety. Their integration with lighting and HVAC systems further enhances overall efficiency, creating a comfortable and secure environment for all occupants.

In summary, Johnson Controls’ GGLS*MP, TGLS*MP, TG8S*MP, and GG8S*MP series presents cutting-edge technologies designed for energy efficiency, ease of use, and versatility. By focusing on comprehensive building management, these products provide optimal performance that aligns with sustainability objectives while enhancing comfort and security. Whether in commercial or residential settings, Johnson Controls continues to lead the way in the intelligent building sector.
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