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

Carrier 58MSA Installation, Start-up, And Operating Instructions Manual Manual pdf 36 page image

4. For approximately 2 sec, short (jumper) the C OM-24v terminalon control to the TEST/TWIN 3/16-inch quick-connect termi-nal on control until the LED goes out. Remover jumper fromterminals. (See Fig. 33.)NOTE: If TEST/TWIN and COM-24v terminals are jumperedlonger than 2 sec, LED will flash rapidly and ignore componenttest request.Component test sequence is as follows:a. LED will display previous status code 4 times.b. Inducer motor starts and continues to run until Step g ofcomponent test sequence.c. After 7 seconds the hot surface igniter is energized for 15sec, then off.d. Blower motor operates on HEAT speed for 10 sec.e. Blower motor operates on COOL speed for 10 sec.f. Inducer motor stops.5. Reconnect R lead to furnace control, remove tape from blowerdoor switch, and re-install blower door.6. Operate furnace per instruction on outer door.7. Verify furnace shut down by lowering thermostat settingbelow room temperature.8. Verify that furnace restarts by raising thermostat setting aboveroom temperature.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, furnace control 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 furnace 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 115-velectrical circuit to furnace.These furnaces are equipped with a manual reset limit switchin burner box. This switch will open and shut off power to gascontrol valve if an overheat condition (flame rollout) occursin burner enclosure. Correct inadequate combustion-air sup-ply or improper venting condition and reset switch. DO NOTjumper this switch. Failure to follow this caution will result inminor unit operation or performance satisfaction.Before operating furnace, check flame rollout manual reset switchfor continuity. 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. Failure to follow this caution will result inminor unit operation or performance satisfaction.1. Remove upper inducer housing drain connection cap. (SeeFig. 44.)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. 45.)5. Remove funnel and tube from inducer housing and replacedrain connection cap and clamp.Step 3—Purge Gas LinesNever purge a gas line into a combustion chamber. Never testfor gas leaks with an open flame. Use a commerciallyavailable soap solution made specifically for the detection ofleaks to check all connections. Failure to follow this warningcould result in fire, explosion, personal injury, or death.If not previously done, purge lines after all connections have beenmade and check for leaks.Step 4—AdjustmentsSET GAS INPUT RATEFurnace gas input rate on rating plate is for installations at altitudesup to 2000 ft.In the U.S.A., the input ratings for altitudes above 2000 ft must bereduced by 2 percent for each 1000 ft above sea level.In Canada, the input ratings must be derated by 5 percent foraltitudes of 2000 ft to 4500 ft above sea level.Furnace input rate must be within ±2 percent of input on furnacerating plate adjusted for altitude.1. Determine natural gas orifice size and manifold pressure forcorrect input.a. Obtain average gas heat value (at installed altitude) fromlocal gas supplier.b. Obtain average gas specific gravity from local gas supplier.c. Verify furnace model. Table 9 can only be used for model58MSA furnaces.d. Find installation altitude in Table 9.NOTE: For Canadian altitudes of 2001 to 4500 ft, use U.S.A.altitudes of 2001 to 3000 ft in Table 9.e. Find closest natural gas heat value and specific gravity onTable 9.f. Follow heat value and specific gravity lines to point ofintersection to find orifice size and manifold pressuresettings for proper operation.EXAMPLE: (0—2000 altitude)Heating value = 1050 Btu/cu ftSpecific gravity = 0.62Therefore: Orifice No. 45Manifold pressure 3.6-in. wc* Furnace is shipped with No. 45 orifices. In this exampleall main burner orifices are the correct size and do not needto be changed to obtain the proper input rate.Check and verify burner orifice size in furnace. NEVER ASSUMEORIFICE SIZE; ALWAYS CHECK AND VERIFY.2. Adjust manifold pressure to obtain input rate.NOTE: Manifold pressure must always be measured with burnerenclosure front REMOVED. Gas meter must always be clockedwith burner enclosure front INSTALLED.36→→