Sequence of Operation Flow Chart
Description of this flow chart can be found in the “SEQUENCE OF OPERATION” section found on page 26.
Switch power on to unit
Thermostat calls for heat
VFD sends power to Blower
Blower engages Prover Switch
Blower runs at low speed
After 30 seconds, Ignition
Control provides power to
Spark Igniter and opens Gas
Valve
Ignition Control maintains spark for up
to 4 seconds and monitors Flame Sensor to determine if Burner is lit
Does Burner | NO |
| |
light? |
|
YES
Ignition Control changes Blower from low speed to high speed after 5 seconds
Ignition Control monitors
flame signal
YES
Loss of flame signal?
NO
Thermostat is satisfied
Blower – off; Blower Prover – opens
Ignition Control – off; Gas Valve – closes
Gas Valve – off
Gas Valve – off
NO |
|
|
|
|
|
|
|
|
|
Is this the third | YES |
| Wait 15 minutes. |
|
|
| |||
|
| Blower runs at |
| |
ignition trial? |
|
| low speed |
|
|
|
|
| |
|
|
|
|
|
NO
YES
Is this the third loss of flame signal?
Figure 24.
27
