Thermo Products CMA1-50N, CMA2-75N service manual V.Starting The Unit A. Sequence Of Operations

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V.STARTING THE UNIT

All installations and services must be performed by qualified service personnel.

V.STARTING THE UNIT

A. SEQUENCE OF OPERATIONS

AT ANY TIME THE					CONTINUOUS SAFE OPERATION CHECK
GAS VALVE IS					IF FLAME SIMULATION CONDITION
NOT ENERGIZED				PRESENT OR ROLL-OUT SWITCH OPENS, SYSTEM
			ENERGIZES INDUCER FAN FOR 15 SECONDS AND CIRCULATOR BLOWER AT
START				HEATING SPEED UNTIL SITUATION CORRECTION



				THERMOSTAT CALLS FOR
				HEAT, CONTACTS CLOSE


		CONTROL BOARD ENERGIZED,
				INDUCER ENERGIZED


		PRESSURE SWITCH SENSES
	ADEQUATE DIFFERENTIAL PRESSURE,
				CONTACTS CLOSE

POWER IS APPLIED TO		POWER INTERRUPTION
THE SILICON NITRIDE		SYSTEM SHUTS OFF,
IGNITOR. IGNITOR		RESTARTS WHEN POWER
WARM-UP IS 20 SECONDS.		IS RESTORED.

START
START		AFTER IGNITOR WARM-UP,
TRIAL		AFTER IGNITOR WARM-UP,
TRIAL		THE GAS VALVE IS
FOR		THE GAS VALVE IS
FOR		ENERGIZED TO OPEN
IGNITION		ENERGIZED TO OPEN
IGNITION

FLAME MUST BE DETECTED		IF FLAME IS NOT DETECTED, THE
WITHIN 4 SECONDS IF		GAS VALVE IS DE-ENERGIZED,
FLAME IS DETECTED, THE		THE IGNITOR IS TURNED OFF AND
FLAME IS DETECTED, THE		THE IGNITOR IS TURNED OFF AND
DELAY-TO-FAN-ON TIME		THE CONTROL BOARD CONTROL GOES
BEGINS (45 SECONDS)		INTO "RETRY" SEQUENCE.

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Contents DOWN FLOW & DIRECT VENT SEALED COMBUSTION INSTALLATION AND SERVICE MANUALFOR YOUR SAFETY GAS FIRED HIGH EFFICIENCY FURNACESECTION TABLE OF CONTENTSI. SAFETY INFORMATION Page Page The vent and air intake elbows must be kept away from bushes, shrubs or any vegetation that may restrict the flow of flue products. It must also be kept clear of any leaves, weeds or other combustible materials. Keep the vent hood clear of snow. Avoid locating the terminals in areas where standing water or condensate drippage may be a problem 1.A windows be opened GAS SUPPLY PRESSURE II. FURNACE SPECIFICATIONS - CMA SERIESDIMENSIONS MODELINSTALLATION PARTS PACKAGE NON-COMBUSTIBLEMATERIAL COMBUSTIBLE MATERIAL.” COMBUSTIBLE MATERIALTable IV. GENERAL INSTALLATION A.FURNACE LOCATIONMODELS CMA Figure 1B Combustible Floor Base Model: 70-BASE Figure 1ACoil Cabinet Cottage Base Model: 01COT-BASE Figure 1C Figure Figure B. BASE INSTALLATION1. Combustible Floor Base Model: 70 BASE Figure C. ALCOVE INSTALLATION2. Cottage Base Model: 01COT BASE Figure D. CLOSET INSTALLATIONE. FUEL PIPING F.GENERAL VENTING REQUIREMENTS Table MAXIMUM VENT LENGTHFigure 6. CMA*-75SHOWN 1. Vent And Combustion Air Pipes H. Direct Venting Through a Sidewall2. Exhaust Vent Termination Elbow Sidewall Venting Page 4. Vent Terminal Location Guidelines Terminations Figure Figure 5.Secure plate to roofFigure K.CONDENSATE DRAIN LINE AND TRAP ASSEMBLY 1. Electrical Branch Supply Circuit Figure L.ELECTRICAL WIRING2.Connection Of Power Supply Wires 3.Connection Of Room Thermostat WiresElectrical Wire Diameter AWG 24 22 20 18 4. BLOWER MOTOR SPEED WIRING Figure Pressure CMA1-50Speed Tap \ StaticPressure CMA2-75Speed Tap \ Static5. FIELD WIRING AND REPLACING WIRING V.STARTING THE UNIT A. SEQUENCE OF OPERATIONS MAIN BURNER OPERATION CALL FOR HEAT SATISFIED OPERATING INSTRUCTIONS B.INITIAL START UPC.ADJUSTMENT OF BTU INPUT RATE D.BURNER ADJUSTMENT GAS PRESSURE CHART FOR CMA* MODEL FURNACESFigure E.SETTING TEMPERATURE RISEF.FURNACE CHECKOUT PROCEDURE VII. DEALER MAINTENANCE VI. INSTALLERS INSTRUCTIONS TO USERB.GENERAL INSPECTION 2.CONDENSATE LINE/TRAP ASSEMBLY4. INDUCER BLOWER ASSEMBLY A.ELECTRICALD.HOUSE AIR BLOWER 1.CLEANING THE COIL AIR SIDE5. GASKETS/SEALING MATERIALS C.HEAT EXCHANGERDIAGNOSTIC FEATURES FILTER MAINTENANCE PROCEDUREFILTER REPLACEMENT VIII. TROUBLESHOOTINGThe LED will also flash once at power-up TROUBLESHOOTING GUIDE AT THE INTEGRATED CONTROL? Yes AFTER GAS VALVE OPENS, DO THE BURNERS IGNITE? DOES SYSTEM RUN UNTIL THERMOSTAT IS SATISFIED? IF LED LIGHT FLASHES APPENDIX – A REPLACEMENT PARTS Page APPENDIX – B WIRING DIAGRAM