Roberts Gorden 75 User Manual

Page of 60
SECTION 11: O
PERATION
 
AND
 M
AINTENANCE
27 of 47
Figure 15: Automatic Burner Control Sequence
Figure 16: Gas Valve for Models UHD[X][S] 75 – 125
Burner Sequence for Ignition Control
Flame Signal
Start Gas Valve
Ignition Spark
Thermostat 24 V
SHUT DOWN
RUN
START
 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 75 – 125 NG
90032505
  Gas Valve 75 – 125 LP
90032506