Carrier 58MSA Installation, Start-up, And Operating Instructions Manual

Also see for 58MSA Series: Service and maintenance instructions User manual Instruction manual Installation, start-up, and operating instructions Installation, start-up, and operating instructions

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Carrier 58MSA Installation, Start-up, And Operating Instructions Manual Manual pdf 32 page image

Make sure limit switch wire does not contact any metalliccomponent such as the gas valve. If wire is shorted, 3-ampfuse on control center will blow.NOTE: If wire to main limit is disconnected longer than 4 sec, thecontrol senses limit circuit is open. Main blower will start and faultretrieval request will be ignored.5. When above items have been completed, the component testsequence will occur as described in the Component TestSequence section above.NOTE: Be sure to record the fault code which is flashed 4 timesat start of component test for further troubleshooting.6. After component test is completed and LED is ON continu-ously indicating the furnace is ready to operate when a signalfrom the thermostat is received, replace main furnace door.INITIATING COMPONENT TEST BY JUMPERING CON-TROL TEST TERMINAL1. Remove main furnace door.2. Remove blower access panel.3. Manually close blower access panel door switch. Use a pieceof tape to hold switch closed.Blower access panel door switch opens 115-v power tocontrol center. No component operation can occur. Cautionmust be taken when manually closing this switch for servicepurposes. Failure to follow this warning could result inelectrical shock, personal injury, or death.4. BRIEFLY short (jumper) TEST, 1/4-in. quick-connect termi-nal on control center (adjacent to the LED diagnostic light)and the C OM terminal on thermostat connection block. (SeeFig. 26.)NOTE: If TEST to COM terminals are jumpered longer than 2 sec,LED will flash rapidly, and retrieval request will be ignored.5. When above items have been completed, the component testsequence will occur as described in the Component TestSequence section above.NOTE: Be sure to record the fault code which is flashed 4 timesat start of component test for further troubleshooting.6. After component test is completed and furnace is operatingproperly, release blower access panel door switch, replaceblower access panel, and replace main furnace door.START-UP PROCEDURESStep 1—General1. Furnace must have a 115-v power supply properly connectedand grounded. Proper polarity must be maintained for correctoperation.NOTE: Proper polarity must be maintained for 115-v wiring. Ifpolarity is incorrect, control center fault indicator light will flashrapidly and furnace will not operate.2. Thermostat wire connections at terminals R, W, G, and Ymust be made at 24-v terminal block on control center.3. Natural gas service pressure must not exceed 0.5 psig (14-in.wc), but must be no less than 0.16 psig (4.5-in. wc).4. Blower access panel must be in place to complete 24-velectrical circuit to furnace.These furnaces are equipped with a manual reset limit switchin burner box. This switch will open if an overheat condition(rollout) occurs in burner enclosure. Correct inadequatecombustion-air supply or improper venting condition andreset switch. DO NOT jumper this switch.Before operating furnace, check each manual reset switch forcontinuity. If necessary, press button to reset switch.Step 2—Prime Condensate Trap with WaterCondensate trap must be PRIMED or proper draining may notoccur. The condensate trap has 2 internal chambers which canONLY be primed by pouring water into the inducer drain sideof condensate trap.1. Remove upper inducer housing drain connection cap. (SeeFig. 38.)2. Connect field-supplied 1/2-in. ID tube to upper inducerhousing drain connection.3. Insert field-supplied funnel into tube.4. Pour 1 quart of water into funnel/tube. Water should runthrough inducer housing, overfill condensate trap, and flowinto open field drain. (See Fig. 39.)5. Remove funnel and tube from inducer housing and replacedrain connection cap and clamp.Step 3—Purge Gas LinesIf not previously done, purge lines after all connections have beenmade and check for leaks.Never purge a gas line into a combustion chamber. Never usematches, candles, flame, or other sources of ignition forpurpose of checking leakage. Use a soap-and-water solutionto check for leakage. Failure to follow this warning couldresult in fire, explosion, personal injury, or death.Step 4—AdjustmentsSET GAS INPUT RATEFurnace gas input rate on rating plate is for installations at altitudesup to 2000 ft. Furnace input rate must be within ±2 percent of inputon furnace rating plate.1. Determine natural gas orifice size and manifold pressure forcorrect input.a. Obtain average yearly heat value (at installed altitude) fromlocal gas supplier.b. Obtain average yearly specific gravity from local gassupplier.c. Verify furnace model. Table 7 can only be used for model58MSA furnaces.d. Find installation altitude in Table 7.NOTE: For Canada altitudes of 2000 to 4500 ft, use U.S.A.altitudes of 5001 to 6000 ft in Table 7.e. Find closest natural gas heat value and specific gravity onTable 7.f. Follow heat value and specific gravity lines to point ofintersection to find orifice size and manifold pressuresettings for proper operation.32