Roberts Gorden Blackheat UHA-Series 30 - Manual (Page 36)

UHA L OW P ROFILE U NIT H EATER I NSTALLATION O PERATION AND S ERVICE M ANUAL
30
Figure 16: Automatic Burner Control Sequence
Figure 17: Gas Valve for Models UHA[X][S] 30 - 45
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.
Axial Fan
30 Seconds Delay 90 Seconds Delay
30 Seconds Post Purge
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.
Pressure Regulator
Gas Outlet
Outlet Pressure
Description Part Number
Gas Valve 30 - 45 NG 90034500
Gas Valve 30 - 45 LP 90034600