Addison UHD150, Installation, Operation & Service Manual

Page: 37 / 68

SECTION 11: O
PERATION AND
M
AINTENANCE
29 of 55
Figure 14: Automatic Burner Control Sequence
Figure 15: Single Stage Gas Valve for Models UHD[X][S][R] 150 – 400
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 150 - 250 NG 90032505
Gas Valve 150 - 250 LP 90032506
Gas Valve 300 - 400 NG 90032520
Gas Valve 300 - 400 LP 90032521