Ducting - 4100 Series

PSC Supply Air Blower

Supply Air Blower Speed

Systems equipped with PSC motors have a 4-speed supply air blower, factory wired to operate in medium low speed for "heating” and in medium high speed for "cooling" and/or a "fan only" thermostat setting.

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.

PSC blower speed selection is made at the supply air blower in the supply air blower plenum.  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: 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.

WARNING

HAZARDOUS VOLTAGE: Risk of electric shock. Can cause injury or death.

Remove Assembly from Box

Remove the supply air blower plenum assembly from the box.  

Remove Metal Plate

The supply air blower is shipped inside the plenum assembly in its operating position and is secured to the plenum by a metal plate to keep the blower from moving during shipping. The metal plate MUST be removed before operating the system. Once removed, it may be discarded.

Adjust the Blower Speed

Adjust blower speed, if necessary, by changing the wiring on the blower speed selection terminals. Refer to the System Air Delivery Matrix for details. The front access cover on the supply air plenum will need to be removed to access these terminals.

Attach Plenum Support Bracket

Locate the plenum support bracket which is shipped in the plenum box. Attach the bracket to the supply air side using the blunt tip screws supplied in the plenum assembly hardware package.

Attach the Wiring Harness

Attach the supply blower wiring harness located in the base of the system to the blower using the connections located on the ends of the harness. Be sure to place any excess wiring in the base of the system below the radiant heat shield.

NOTE: When routing the harness to the supply air blower, the harness must route to the side of the air deflector in the bottom of the supply air blower housing.

Verify Motor is Installed Correctly

Verify that the blower is installed in the plenum with the motor facing away from the system.

Connect the Plenum to the Comfort Plus

Attach the supply air blower plenum to the Comfort Plus by drilling two 1/8” holes per edge and using the self tapping screws supplied in the hardware package.

Connect the Ducting to the Comfort Plus

Connect both the return air and supply air ducting systems in the structure to the Comfort Plus system. Be sure the air holes just above the air outlet on the right side are contained in the duct system.

NOTE: If the Comfort Plus system is installed in a small enclosed area (less than 400 square feet), a minimum of a 24"x 24" opening must be installed into the area where the system is located. In addition, a 6" x 6" non-closing type register must be cut into the return air duct. Refer to the Placement and Clearance Requirements section for more information.