Carrier 90MU Horizontal Wheel Centering, Concentric Wheel Alignment, Make Condenser Connections

DIMENSION “D” MUST BE

EQUAL ALL AROUND

FIGURE 3 - HORIZONTAL WHEEL CENTERING

FIGURE 4 - CONCENTRIC WHEEL ALIGNMENT

Step 6 – Check Fan Shaft and Wheel Alignment- HORIZONTAL WHEEL CENTERING - All wheels must be horizontally centered between the inside edges of their fan scroll ventures (Figure. 3).

Adjust as follows:

a. Loosen set screws holding wheel to shaft. b. Center the wheel by sliding it horizontally. c. Re-tighten set screws.

CONCENTRIC ALIGNMENT - Shaft and wheels must be concentrically centered with the venturi (Figure. 4). Shaft bearings are supported by bearing supports. If shaft and wheels are concentrically misaligned from shipping shock, it is possible to re-bend bearing support arms to original positions. Replace the bearing support if it has been extensively damaged during shipping.

Step 7 - Install Ventilation-Air Ductwork (If required)- Connect ventilation ducts to flanges on outside-air supply opening (Figure. 2) using a flexible connection. Attach ductwork to ship structure, insulate and cover with vapor barrier to reduce sound transmission and prevent vapor condensation.

Weatherproof external ductwork, joints, and openings in accordance with applicable codes. Ducts passing through an unconditioned space must be insulated and covered with a vapor barrier.

Step 8 - Check Return-Air Filters - Ensure filters shipped with unit are in place. Never operate unit without return air filters in place.

Step 9 - Check Compressor Spring Mounts (*08 & *12 size only) - The compressors are held rigid in shipment by bolts extending through a washer, grommet and compressor foot into a weld nut.

Loosen each bolt (4 per compressor) until compressor floats freely on springs. Then re-tighten bolts until there is slight pressure on the neoprene gasket. This will steady the compressor and prevent start and stop rocking.

The compressors have reversible oil pumps that operate in either direction; therefore, the direction of rotation need not be checked.

Step 10 - Make Condenser Connections

UNIT MOUNTED 90MA UNITS- Piping arrangements for condenser cooling water are shown in Figure. 5. Condensers have water inlet and outlet connections as shown in Figure 6.

Connect condenser water supply and return lines as indicated. When connecting water lines, hold the condenser inlet and outlet stubs firmly with a wrench at the female pipe thread hex fitting to prevent twisting. Do not use water lines smaller than connection sizes shown in Figure 6. Observe all applicable plumbing and sanitary codes.

FIGURE 5 - TYPICAL CONDENSER WATER PIPING

Install water-regulating valve in water supply line outside cabinet as follows.

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations

Printed in U.S.A. Pg 9 90MA-3SI SUPERCEDES FORM 62-02971-00 09-2009