
41
START
TRIAL
FOR
IGNITION
CONTINUOUS SAFE OPERATION CHECK
IF FLAME SIMULATION CONDITION
PRESENT OR ROLL-OUT SWITCH OPENS, SYSTEM
ENERGIZES INDUCER FAN FOR 15 SECONDS AND CIRCULATOR BLOWER AT
HEATING SPEED UNTIL SITUATION CORRECTION
THERMOSTAT CALLS FOR
HEAT, CONTACTS CLOSE
POWER INTERRUPTION
SYSTEM SHUTS OFF,
RESTARTS WHEN POWER
IS RESTORED.
PRESSURE SWITCH SENSES
ADEQUATE DIFFERENTIAL PRESSURE,
CONTACTS CLOSE
CONTROL BOARD ENERGIZED,
INDUCER ENERGIZED
AFTER IGNITOR WARM-UP,
THE GAS VALVE IS
ENERGIZED TO OPEN
IF FLAME IS NOT DETECTED, THE
GAS VALVE IS DE-ENERGIZED,
THE IGNITOR IS TURNED OFF AND
THE CONTROL BOARD CONTROL GOES
INTO "RETRY" SEQUENCE.
START
AT ANY TIME THE
GAS VALVE IS
NOT ENERGIZED
POWER IS APPLIED TO
THE SILICON NITRIDE
IGNITOR. IGNITOR
WARM-UP IS 17 SECONDS.
FLAME MUST BE DETECTED
WITHIN 4 SECONDS IF
FLAME IS DETECTED, THE
DELAY-TO-FAN-ON TIME
BEGINS (15 SECONDS)
V. STARTING THE UNIT
A. SEQUENCE OF OPERATIONS
Содержание CMA4-50D36N
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Страница 38: ...33 4 BLOWER MOTOR SPEED WIRING Figure 15...
Страница 62: ...57 APPENDIX A REPLACEMENT PARTS...
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Страница 66: ...61 APPENDIX B WIRING DIAGRAMS...