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 |
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Switch | C |
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Ignition Spark
Start Gas Valve
Flame Signal
| 30 Seconds Purge* | 30 Seconds Post |
P | NO |
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| NC | ts = 10 Seconds |
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*Purge time begins at pressure switch change over.
Required Incoming Signals
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| If at any stage the flame fails, the control will retry |
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Signals Output By Control | for ignition. The control has four trials for ignition | |||||||||||||||||||||||||||||||||||||||||||||||||||
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| before a one hour lockout. |
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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 Automatic Burner Control Sequence, Gas Valve, End View, Regulator, Gas Inlet, Shut Down](/prints/roberts-gorden-uhdxsr-75-uhdxsr-125/34848/30.1080/figure-14-gas-valve-end-view-regulator.1080.webp)