Carrier 58UVB series Installation, Start-up, And Operating Instructions Manual

Also see for 58UVB series: Owner's information manual Owner's manual Installation, start-up, and operating instructions

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Carrier 58UVB series Installation, Start-up, And Operating Instructions Manual Manual pdf 43 page image

43Continuous Blower Speed Selection from ThermostatTo select different continuous--blower speeds from the roomthermostat, momentarily turn off the FAN switch or push buttonon the room thermostat for 1--3 seconds after the blower motorBLWM is operating. The furnace control CPU will shift thecontinuous--blower airflow from the factory setting to the nexthighest CF selection airflow as shown in Fig. 39. Momentarilyturning off the FAN switch again at the thermostat will shift thecontinuous--blower airflow up one more increment. If you repeatthis procedure enough, you will eventually shift thecontinuous--blower airflow to the lowest CF selection as shownin Fig. 39. The selection can be changed as many times as desiredand is stored in the memory to be automatically used following apower interruption.This feature is disabled when blower off delay is set for 180 sec.HEAT PUMPSee Fig. 45--48 for thermostat connections.When installed with a heat pump, the furnace controlautomatically changes the timing sequence to avoid long bloweroff times during demand defrost cycles. Whenever W/W1 isenergized along with Y1 or Y/Y2, the furnace control CPU willtransition to or bring on the blower motor BLWM at coolingairflow, low--heat airflow, or the midrange airflow, whichever isthe lowest. The blower motor BLWM will remain on until themain burners ignite, then shut OFF and remain OFF for 25seconds before coming back on at heating airflow. When theW/W1 input signal disappears, the furnace control begins anormal inducer post--purge period while changing the blowerairflow. If Y/Y2 input is still energized, the furnace control CPUwill transition the blower motor BLWM airflow to coolingairflow. If Y/Y2 input signal disappears and the Y1 input is stillenergized, the furnace control CPU will transition the blowermotor BLWM to low--cooling airflow. If both the Y1 and Y/Y2signals disappear at the same time, the blower motor BLWM willremain on at low--heat airflow for the selected blower--OFF delayperiod. At the end of the blower--OFF delay, the blower motorBLWM will shut OFF unless G is still energized, in which casethe 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. 33.)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:1. The furnace control CPU turns the inducer motor IDMON at medium speed and keeps it ON through step c.2. After waiting 15 seconds, the furnace control CPU turnsthe hot surface igniter ON for 15 seconds, then OFF.3. The furnace control CPU then turns the blower motorBLWM ON at midrange airflow for 15 seconds, then OFF.4. 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 accesspanel or Service/Status Code Instructions for explanation ofstatus 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 ataltitudes up 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 pressurefor correct input.a. Obtain average heat value (at installed altitude) fromlocal gas supplier.b. Obtain average specific gravity from local gas supplier.c. Verify furnace model. Table 11 can only be used formodel 58UVB 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 gravityin Table 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 thisexample, all main burner orifices are the correct size anddo not need to be changed to obtain proper input rate.g. Check and verify burner orifice size in furnace.NEVER ASSUME ORIFICE SIZE; ALWAYSCHECK AND VERIFY.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 adjustmentscrews for low-- and high--heat gas valve regulators.(See Fig 51.)c. Move setup switch SW1--2 on control center to ONposition. (See Fig. 33.) This keeps furnace locked inlow--heat operation.d. Jumper R and W/W1 thermostat connections oncontrol to start furnace.e. Turn low--heat adjusting screw (3/32) hex Allenwrench) counterclockwise (out) to decrease input rateor clockwise (in) to increase input rate.NOTE: DO NOT set low--heat manifold pressure less than1.3--in. wc or more than 1.7--in. wc for natural gas. If manifoldpressure is outside this range, change main burner orifices toobtain manifold pressure in this range.58UVB