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

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Carrier 58MVP Installation, Start-up, And Operating Instructions Manual Manual pdf 41 page image

motor BLWM will shut OFF unless G is still energized, in whichcase the blower motor BLWM will operate at continuous blowerairflow.COMPONENT TESTThe furnace features a component test system to help diagnose asystem problem in the case of a component failure. To initiate thecomponent test procedure, ensure that there are no thermostatinputs to the control and all time delays have expired. Turn onsetup switch SW1-6 (See Fig. 32.)NOTE: The component test feature will not operate if the controlis receiving any thermostat signals or until all time delays haveexpired.The component test sequence is as follows:a. The furnace control CPU turns the inducer motor IDM ONat medium speed and keeps it ON through step c.b. After waiting 15 seconds, the furnace control CPU turnsthe hot surface igniter ON for 15 seconds, then OFF.c. The furnace control CPU then turns the blower motorBLWM ON at midrange airflow for 15 seconds, then OFF.d. After shutting the blower motor BLWM OFF, the furnacecontrol CPU shuts the inducer motor IDM OFF.NOTE: The EAC terminals are energized when the blower isoperating.After the component test is completed, 1 or more status codes (11,25, 41, or 42) will flash. See Service Label on blower access panelor Service/Status Code Instructions for explanation of status codes.NOTE: To repeat component test, turn setup switch SW1-6 toOFF and then back ON.Step 6—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 rating for altitudes above 2000 ft must bereduced by 2 percent for each 1000 ft above sea level.In Canada, the input rating must be derated by 5 percent foraltitudes of 2000 ft to 4500 ft above sea level.Adjust manifold pressure to obtain input rate.Furnace input rate must be within ±2 percent of input rate onfurnace rating plate.1. Determine natural gas orifice size and manifold pressure forcorrect input.a. Obtain average heat value (at installed altitude) from localgas supplier.b. Obtain average specific gravity from local gas supplier.c. Verify furnace model. Table 11 can only be used for model58MVP Furnaces.d. Find installation altitude in Table 11.NOTE: For Canadian altitudes of 2000 to 4500 ft, use U.S.A.altitudes of 2001 to 3000 ft in Table 11.e. Find closest natural gas heat value and specific gravity inTable 11.f. Follow heat value and specific gravity lines to point ofintersection to find orifice size and low- and high-heatmanifold pressure settings for proper operation.EXAMPLE: (0—2000 ft altitude)Heating value = 1050 Btu/cu ftSpecific gravity = 0.62Therefore: Orifice No. 45Manifold pressure: 3.8-in. wc for high heat1.6-in. wc for low heat* Furnace is shipped with No. 45 orifices. In this example,all main burner orifices are the correct size and do not needto be changed to obtain proper input rate.g. Check and verify burner orifice size in furnace. NEVERASSUME ORIFICE SIZE; ALWAYS CHECK ANDVERIFY.2. Adjust manifold pressure to obtain input rate.a. Remove burner enclosure front.NOTE: Manifold pressure MUST always be measured with theburner box cover REMOVED.b. Remove regulator seal caps that conceal adjustment screwsfor low- and high-heat gas valve regulators. (See Fig. 62.)c. Move setup switch SW1-2 on control center to ON posi-tion. (See Fig. 32.) This keeps furnace locked in low-heatoperation.d. Jumper R and W/W1 thermostat connections on control tostart furnace.e. Turn low-heat adjusting screw (3/32) hex Allen wrench)counterclockwise (out) to decrease input rate or clockwise(in) to increase input rate.NOTE: DO NOT set low-heat manifold pressure less than 1.3-in.wc or more than 1.7-in. wc for natural gas. If manifold pressure isoutside this range, change main burner orifices to obtain manifoldpressure in this range.DO NOT bottom out gas valve regulator adjusting screw.This can result in unregulated manifold pressure and result inexcess overfire and heat exchanger failures.NOTE: If orifice hole appears damaged or it is suspected to havebeen redrilled, check orifice hole with a numbered drill bit ofcorrect size. Never redrill an orifice. A burr-free and squarelyaligned orifice hole is essential for proper flame characteristics.f. Move setup switch SW1-2 to OFF position after completinglow-heat adjustment.g. Jumper R and W/W1 and W2 thermostat connections onfurnace control. (See Fig. 32.) This keeps furnace locked inhigh-heat operation.h. Turn high-heat adjusting screw (5/64 hex Allen wrench)counterclockwise (out) to decrease input rate or clockwise(in) to increase rate.NOTE: DO NOT set high-heat manifold pressure less than 3.2-in.wc or more than 3.8-in. wc for natural gas. If manifold pressure isoutside this range, change main burner orifices to obtain manifoldpressures in this range.i. When correct input is obtained, replace caps that concealgas valve regulator adjustment screws. Main burner flameshould be clear blue, almost transparent. (See Fig. 64.)j. Remove jumpers R to W/W1 and R to W23. Verify natural gas input rate by clocking gas meter.NOTE: Be sure all pressure tubing, combustion-air and ventpipes, and burner enclosure front are in place when checking inputby clocking gas meter.41