PVI Industries 180 - Manual (Page 28)

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PV500-46U 06/12
8. Delay-On Relay - Once the Delay-On (Low Fire Hold) Relay has timed out, it energizes the Modulation Release
Relay (SPDT) to enable the analog signal from the TempTrac to the VFD to regulate the speed of the blower.
a. The TempTrac will continue to monitor the stored water temperature in the tank.
b. When the setpoint temperature is reached the call-for-heat signal to the flame safeguard control is
discontinued.
c. The flame safeguard control deenergizes the VFD blower system and the gas valve, thereby suspending
burner operation.
d. As heat is transferred to the building, the water heater loop temperature will fall below the set point. The
TempTrac will sense this condition and begin the call-for-heat sequence again.
9. Flame Safeguard LED Diagnostic Indicator - If the Fenwal Flame Safeguard Control at any time during the
operating sequence senses an improper operating state and locks out, the diagnostic red LED located on the
control board will flash to indicate one of the following conditions exist:
LED INDICATION FAULT MODE
On Normal Operation
OFF Internal Control Failure – check power
1 Flash Airflow Fault
2 Flashes Erroneous Flame Signal
3 Flashes Ignition Lockout
4 Flashes Hot Surface Igniter Fault
5 Flashes Low Voltage (24 VAC)
6 Flashes Valve Relay Problem