Part 17 Description PSC - 3100 Series

For air delivery, the Comfort Plus is equipped with a 1/3, 1/2, or 3/4 hp, 4-speed supply air blower and is factory wired to operate in medium low speed for heating and in medium high speed for cooling and/or a fan only thermostat setting.

• 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. (Order Item #1301576).

• When replacing capacitors, replace only with a capacitor having the same mfd, voltage, and AFC ratings. See motor nameplate for requirements.

Blower speed selection on the 3100 series is made at the low and high speed relays on the Base I/O relay board inside the electrical compartment.  Refer to the Line Voltage Wiring Diagram for location of these relays.  The low speed relay controls the "heating" blower speed and the high speed relay controls the "cooling" blower speed.  Select the blower speed desired and connect the corresponding wire to the low or high speed relay.

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.  

• Ordering Information

• System Air Delivery Matrix