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

Also see for 58UHV Series: Installation, start-up, and operating instructions User's information manual Installation, start-up, and operating instructions Installation, start-up, and operating instructions

Contents

Carrier 58UHV Installation, Start-up, And Operating Instructions Manual Manual pdf 13 page image

a. When the thermostat calls for heat, the R-W/W1 circuitcloses for low-stage or the R to W1-and-W2 circuits closefor high-stage. The furnace control performs a self-check,verifies pressure switch contacts for low- and high-stageLPS and HPS are normally open, and starts the IDM in lowspeed or high speed as appropriate.b. Switching from low- to high-stage gas heat—If the ther-mostat R-W/W1 circuit for low-stage is closed and theR-W2 circuit for high-stage closes, the control CPUswitches the IDM speed from low to high. The HPSRcloses. When the IDM provides sufficient pressure to closethe HPS, the high-stage gas valve solenoid GV is ener-gized. The BLWM switches to high-stage airflow 5 secafter the R-W2 circuit closes.c. Switching from high- to low-stage gas heat—If the ther-mostat R-W2 circuit for high-stage opens and the R-W/W1circuit for low-stage remains closed, the control CPUswitches the IDM speed from high to low. The HPSR opensto de-energize the high-stage gas valve solenoid GV. Whenthe IDM reduces pressure sufficiently, the HPS opens. Thelow-stage gas valve solenoid GV remains energized as longas the LPS remains closed. The BLWM switches tolow-stage airflow 5 sec after the R-W2 circuit opens.3. Cooling Modea. Single-Speed Cooling Outdoor Unit (See Fig. 11 forthermostat connections.)(1.) The thermostat closes the R to G-and-Y circuits. TheR-Y circuit starts the outdoor unit, and the R toG-and-Y/Y2 circuits start the furnace BLWM oncooling speed.(2.) The terminals EAC-1 and EAC-2 are energized with115v when the BLWM is operating.(3.) When the thermostat is satisfied, the R to G-and-Ycircuits are opened. The outdoor unit stops, and thefurnace BLWM continues operating at cooling airflowfor an additional 90 sec.b. Two-Speed Cooling Outdoor Unit (See Fig. 12 for thermo-stat connections.)(1.) The thermostat closes the R to G-and-Y1 circuits forlow cooling or closes the R to G-and-Y1-and-Y/Y2circuits for high cooling. The R to Y1 circuit operatesthe outdoor unit on low cooling speed. The R toG-and-Y1 circuit operates the furnace BLWM at lowcooling airflow (65% of single-speed cooling airflow;different airflow than for low-gas heat). The R toY1-and-Y2 circuits operate the outdoor unit on high-cooling airflow, and the R to G-and-Y/Y2-and-Y1circuits operate the furnace BLWM at high-coolingairflow. Two-speed high-cooling airflow is 105% ofsingle-speed cooling airflow.NOTE: Y1 is found in the outdoor unit. The furnace control CPUcontrols BLWM airflow by sensing only G-and-Y1 for low-cooling airflow and G-and-Y1-and-Y/Y2 for high-cooling airflow.(2.) Terminals EAC-1 and EAC-2 are energized with 115vwhen the BLWM is operating on either coolingairflow.(3.) When the thermostat is satisfied, the R to G-and-Y1or R to G-and-Y1-and-Y/Y2 circuits open. The out-door unit stops, and the furnace blower continuesoperating on the same cooling airflow for an addi-tional 90 sec.4. Continuous-Blower Modea. When the R to G circuit is closed by the thermostat, theBLWM operates at LOW, MED, or HI (50%, 65%, or100% of single-speed cooling airflow; different than low-gas heat airflow). LOW, MED, and HI selections aredescribed in Set-up Procedures. Terminals EAC-1 andEAC-2 are energized with 115v as long as the BLWM isoperating.b. During a call for heat, the BLWM stops during ignitorwarm-up (17 sec), ignition (7 sec), and blower-on delay (45sec), allowing the furnace heat exchangers to heat upquickly, after which the BLWM operates at the appropriategas heating airflow.c. The BLWM reverts to continuous-blower airflow after theheating cycle is completed. In high-stage gas heating, thefurnace control CPU and ICM2+ motor control hold theBLWM at low-stage airflow for a 90-sec blower-off delayperiod (regardless of selected blower-off delay) beforereverting to continuous-blower airflow.d. When the thermostat calls for low-cooling, the BLWMswitches to low-cool airflow or the selected continuous-blower airflow, whichever is greater. Note that a HIselection for continuous-blower airflow will provide morethan normal airflow during 2-speed low-cooling. When thethermostat is satisfied, the BLWM switches to continuous-blower airflow.e. When the thermostat calls for high cooling, the BLWMoperates at high-cool airflow. When the thermostat issatisfied, the BLWM operates an additional 2 sec athigh-cool airflow before reverting back to continuous-blower airflow.f. When the R-G circuit is opened, the BLWM continuesoperating for an additional 90 sec, if no other functionrequires BLWM operation.5. Heat Pump ModeNOTE: A dual-fuel thermostat or accessory interface kit isrequired with single-speed heat pumps. See dual-fuel thermostat orinterface kit Installation Instructions for single-speed heat pumpthermostat and interface connections. No interface kit is needed for2-speed heat pumps. See 2-speed heat pump Installation Instruc-tions to determine whether a standard or dual-fuel heat pumpthermostat is required and for thermostat connections.NOTE: See TSTAT Price Page for dual-fuel thermostat orderingnumber.a. Single-Speed Heat Pump Cooling(1.) The thermostat and interface kit close the R toY/Y2-and-G-and-O circuits to operate the furnaceBLWM at cooling airflow. The Y/Y2 input to thefurnace control is necessary to provide adequate cool-ing airflow.(2.) Terminals EAC-1 and EAC-2 are energized with 115vwhen the BLWM is operating.(3.) When the thermostat is satisfied, furnace BLWMcontinues operating at the cooling airflow for anadditional 90 sec.b. Two-Speed Heat Pump Cooling(1.) The thermostat R to G-and-Y1-and-O circuits operatethe furnace BLWM at low-cool airflow. The thermo-stat R to G-and-Y/Y2-and-Y1-and-O circuits operatethe furnace BLWM at high-cool airflow (105% ofsingle-speed cooling airflow).13