UHD LOW PROFILE DUCT FURNACE INSTALLATION OPERATION AND SERVICE MANUAL
Figure 13: 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
| 30 Seconds Purge* | 30 Seconds Post |
P | 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 | for ignition. The control has four trials for ignition | |||||||||||||||||||||||||||||||||||||||||||||||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| before a one hour lockout. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
Figure 14: Gas Valve
END VIEW | TOP VIEW |
Regulator
½PSI 
C
IN
OFF
Gas Inlet
ON
Outlet
Pressure
Inlet Pressure
Description | Part Number |
Gas Valve NG | 90032505 |
Gas Valve LP | 90032506 |
24
![Roberts Gorden UHD[X][S][R] 75, UHD[X][S][R] 125 service manual END View](/prints/roberts-gorden-uhdxsr-75-uhdxsr-125/1022988/30.1080/end-view.1080.webp)