Roberts Gorden UHD[X][S][R] 75 Furnace User Manual


 
UHD LOW PROFILE DUCT FURNACE INSTALLATION OPERATION AND SERVICE MANUAL
24
Figure 13: Automatic Burner Control Sequence
Figure 14: Gas Valve
Burner Sequence for Ignition Control
Flame Signal
Start Gas Valve
Ignition Spark
Thermostat 24 V
SHUT DOWN
RUNSTART
ts = 10 Seconds
Signals Output By Control
Required Incoming Signals
Flue Blower
Pressure
Switch
P
C
NO
NC
30 Seconds Purge*
*Purge time begins at pressure switch change over.
30 Seconds Post
If at any stage the flame fails, the control will retry
for ignition. The control has four trials for ignition
before a one hour lockout.
½PSI IN
C
ON
OFF
Regulator
Outlet
Pressure
Gas Inlet
Inlet Pressure
TOP VIEW
END VIEW
Description Part Number
Gas Valve NG 90032505
Gas Valve LP 90032506