4100 series heating systems equipped with PSC motors can include a 1/3, 1/2, or 3/4 hp, 4-speed supply air blower motor. They are factory wired to operate in medium low speed for "heating" and in medium high speed for "cooling" and/or a "fan only" thermostat setting. Use the system air delivery matrix to determine which blower speed is appropriate for the application.
NOTE: When interfacing the Comfort Plus system with a heat pump, the blower speed connected to the high speed relay is used for both heating and cooling. This is the blower speed connected to the blue/black wire.
NOTE: When replacing capacitors, replace only with a capacitor having the same microfarad, voltage, and AFC ratings. See motor nameplate for requirements.
Blower speed selection is made at the supply air blower. To change blower speed for either "heating" or "cooling" modes, detach the quick disconnect terminals at the supply air blower. Select the blower speed and connect the corresponding wires.
NOTE: Proper duct design and air flow are critical to achieve optimum system performance. A poorly designed duct system and/or improper air flow can cause system inefficiencies, air noise, and condensate drain problems. In applications where poor air flow conditions exist along with high humidity, it may be necessary to install a secondary condensate drain pan.
The current draw of the 1/2 hp PSC motor is dependent on many items. First motor speed. The four speeds will produce full load currents of 4.7, 3.0, 2.1, and 1.6 amps respectively. In addition to motor speed, the static pressure, relative humidity, and other installation factors must be taken into consideration.