PVI Industries PV500-45U manual Loss of Flame Signal, LED Indication Fault Mode

Page 27

4.Proof of Air Pressure Switch - The control will look for a signal from the airflow-proving switch, indicating that the blower is operating:

a.When the airflow generated by the blower is sufficient to cause the differential air switch to close, the 15 - second pre-purge delay will start.

b.During this period any flue products or combustible gases which may have settled in the water heater are evacuated.

5.Heat-Up- Following the pre-purge delay, the hot surface igniter will be energized:

a.The flame control will monitor the current applied to the hot surface igniter.

b.If the flame control determines the proving current meets the threshold, a dwell time delay starts to assure the hot surface igniter has sufficient time to reach ignition temperature.

6.Ignition - When dwell time is completed a 4-second Trial for Ignition (TFI) period is initiated:

a.The Delay-On (Low Fire Hold) Relay and the Gas Safety Valves are energized.

b.During TFI the flame safeguard control will monitor the flame using flame rectification through the hot surface igniter.

c.If the flame control senses the presence of flame before the end of the TFI period, the igniter will be de- energized and the flame control will continue to monitor the flame, through the igniter, until the operating thermostat ends the call for heat condition.

7.Loss of Flame Signal

a.If the igniter fails to sense flame at any time, the igniter and gas valve will be de-energized and the flame control will reset and begin the call-for-heat sequence again. This will occur 3 times (one time if CSD-1) before the flame control will lockout.

b.When the call for heat condition ends or flame failure occurs following the third TFI period (one time if CSD- 1), a 30-second post-purge period will begin. This period of blower operation will exhaust any remaining combustion products from the system.

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

 

 

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PV500-45U 06/12

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Contents Installation & Maintenance Manual Table of Contents Remote Connections Terminal Strip Operating and Safety ControlsTroubleshooting Guide Replacement Parts Temptrac Electronic Controller PanelProduct Safety Information Safety ConsiderationsBelow scalding temperatures Standard Features and Equipment Series Series Series Electrical Requirements Water Heater InstallationChecking Equipment Before You Install CodesInlet and Outlet Connections Service ClearancesClearances To Combustible Surfaces General Piping GuidelinesPV500-45U 06/12 PV500-45U 06/12 Optional Condensate Neutralization System GAS Supply and Piping Inlet Pressure NAT. GASConvert Fittings to Equivalent Straight Pipe Inches Single Unit Installation Suggested Pipe SizeMultiple Unit Installations GAS Piping Size Chart Nominal Iron Length of Pipe in Straight FeetCombustion and Ventilation AIR Vertical or Horizontal Remote Air Duct Termination Duct Fitting Equivalent Length Duct PipeVenting Venting the TriconMaximum Category IV Vent Length Equivalent Length Combining Category IV Vents Vent Fitting Equivalent Length Vent PipeTemperature and Pressure Relief Valve s Operating and Safety ControlsHigh Water Temperature Limit Control Cathodic ProtectionElectronic Low Water Cut-Off Optional Clock Temptrac Electronic Controller PanelSET DownTo View The Setpoint To Change The SetpointTo Change Other Parameters Remote Connections Terminal Strip LED Display Alarm MessagesAlarm Cause Results of Alarm Condition Message Recommended ActionIncoming 120VAC Sequence of OperationLED Indication Fault Mode Loss of Flame SignalInitial Startup Turn-on main gas shutoff valve PV500-45U 06/12 Gas Train Illustration for Models 65 through Gas Train Illustration for Models 40 throughProblem Probable Cause Corrective Action Troubleshooting GuideReplacement Parts Replacement PartsControl Panel Contact factory for more information Burner Assembly Optional components may or may not be shown Item No Qty PVI Part No Description Contact factory for more informationPeriodic Maintenance PV500-45U 06/12 Recommended Maintenance Schedule PV500-45U 06/12 PV500-45U 06/12
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