Installation, Operation & Maintenance Manual
IM-895
7
Control Cabinet Features
1. Non-Fused Disconnect Switch
2. Control Power Transformer
3. Flame Safeguard Control
4. Control Relay
5. Air Flow Proving Switch
6. 24V Isolation Transformer
Feature and Factory-Mounted Option Locations
1. Non-Fused Disconnect Switch
– Factory-installed on the stationary panel next to the door, the switch provides a convenient
method of turning off power to the unit. When in the "OFF" position, power is disconnected to all unit wiring electrically
following the switch but remains energized before the switch.
2. Control Power Transformer and Fuses
– All units include a transformer used to reduce the supply voltage to the voltage
required for the unit controls.
3. Flame Safeguard Control
– The flame safeguard control monitors safety devices to determine if the gas ignition sequence
should be initiated. Once initiated, the control will also monitor a flame rod flame sensor to verify burner flame. The control
includes a pre-purge timer to clear any residual gas in the unit before ignition can be initiated.
7. High Temperature Limit Thermostat
8. Temperature Control Amplifier
9. Regulating Valve
10. Main Gas Valve
11. Modulating Gas Valve
12. Gas Pressure Test Port
If equipped with the factory installed disconnect switch option, when the switch is in the "OFF" position, supply power remains energized
at the supply power terminal strip and the top of the disconnect switch. When providing service on or near these terminals, building supply
power to the unit should be de-energized.
WARNING