Roberts Gorden UHD[X][S][R] 225 Automatic Burner Control Sequence, Gas Valve, End View, Top View

UHD STANDARD DUCT FURNACE INSTALLATION OPERATION AND SERVICE MANUAL

Figure 11: Automatic Burner Control Sequence

Burner Sequence for Ignition Control

START

Thermostat 24 V

RUN

SHUT DOWN

Flue Blower

Pressure
Switch	C

Ignition Spark

Start Gas Valve

Flame Signal

P

30 Seconds Purge*	30 Seconds Post Purge
NO
NC	ts = 10 Seconds

*Purge time begins at pressure switch change over.

Required Incoming Signals

If at any stage the flame fails, the control will retry

Signals Output By Control

Figure 12: Gas Valve

for ignition. The control has four trials for ignition before a one hour lockout.

END VIEW	TOP VIEW
	Regulator
	½PSI
	C
	IN
		ON
Gas Inlet	OFF	Outlet
		Pressure
	Description	Part Number
	Gas Valve 150 - 225 NG	90032505
	Gas Valve 150 - 225 LP	90032506
	Gas Valve 250 - 400 NG	90032520
Inlet Pressure	Gas Valve 250 - 400 LP	90032521
22