Lochinvar 999 - 750, 399 Operation and Diagnostic Lights, Ignition and Control Timings, Table-V

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.

OPERATION AND DIAGNOSTIC LIGHTS

The control panel has up to 11 indicating and diagnostic lights to show all major steps of operation and control sensed malfunctions.

FIG. 53 Exterior Control Panel with Operation/Diagnostic Lights and LCD Display

	TABLE-V
Status LED Diagnostic Codes
Code
Sequence	Condition Lights
Prepurge 1	Operation of combustion
	air fans before ignition on
	stages 1 and 2.
Prepurge 2	Operation of combustion
	air fans before ignition on
	stages 3 and 4.
Trial for Ignition 1	Hot surface igniter 1
	preparing to light
	burners.
Trial for Ignition 2 (if equipped) Hot surface igniter 2
	preparing to light burners.
Stage 1 On	Burners for stage 1
	operating.
Stage 2 On	Burners for stage 2
	operating.
Stage 3 On (if equipped)	Burners for stage 3
	operating.
Stage 4 On (if equipped)	Burners for stage 4
	operating.
Status 1	Remote status light
	for ignition module #1.
Status 2 (if equipped)	Remote status light for
	ignition module #2.
Alarm	Indicates flame failure on
	either ignition module and
	will indicate additional
	alarms if the alarm on any
	failure option is
	purchased.

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