Operation And Diagnostic Lights, Prepurge, Post-purge

Installation and

Service Manual

CAUTION: Control panel is heavy and awkward to handle when removed. Carefully support the control panel when removing.

Ignition and Control Timings

Proven Pilot Hot Surface Ignition System M-9 on 990,000 through 2,070,000 Btu/hr models with two hot surface ignition modules.

Hot Surface Ignition Module Timings (Nominal)

Prepurge:

15 Seconds

Hot Surface Igniter Heat-up Time:

25- 35 seconds

Main Burner Flame Establishing Period:

4 Seconds

Failure Response Time:

0.8 Seconds at less than 0.5 µA flame current

Flame Current:

5 - 15 µA

Time Delay Between Stages 1&2 and 3&4*:

15 Seconds

399,999 - 750,000 TIME DELAY stages 1 and 2 ONLY.

Note: Delay starts from the beginning of the ignition process. In order to achieve a 15 second delay, a 60 second delay would have to be programmed. Allow 45 seconds for the ignition process.

Post-purge:

30 Seconds

Pump Delay Timing:

30 seconds minimum after burner shutdown up to a value of ΔT MIN (adjustable from 1°F to 20°F)

*You can program a time delay of up to five minutes into the temperature controller. This only applies to Mode 1 and Mode 2 operation. Mode 3 does not have any stage delay capability. It is recommended, but not required, that the building control system have a delay between the stages to allow time for the system temperature to settle before additional stages are applied to the load. This will help prevent short cycling.