Sunlife Enterprises DM240, DM300, DM180 Phasing, Checking Air Supply Cfm, Belt Adjustment

356214-XIM-A-0108

PHASING

YORK MODEL DM, units are properly phased at the factory. Check for proper compressor rotation. If the blower or compressors rotate in the wrong direction at start-up, the electrical connection to the unit is mis- phased. Change the incoming line connection phasing to obtain proper rotation. (Scroll compressors operate in only one direction. If the scroll is drawing low amper- age, has similar suction and discharge pressures, or producing a high noise level, the scroll is misphased).

Scroll compressors require proper rotation to operate correctly. Units are properly phased at the factory. Do not change the internal wiring to make the blower, condenser fans, or compres- sor rotate correctly.

CHECKING AIR SUPPLY CFM

The RPM of the supply air blower will depend on the required CFM, the unit accessories or options and the static resistances of both the supply and the return air duct systems. With this information, the RPM for the supply air blower and the motor pulley adjustment (turns open) can be determined from the Blower Per- formance Data Tables.

FIGURE 17 - BELT ADJUSTMENT

Note the following:

1.The supply air CFM must be within the limitations shown in the Unit Application Data Table 1.

2.Pulleys can be adjusted in half turn increments.

3.The tension on the belt should be adjusted as shown in the Belt Adjustment Figure 17.

34 Johnson Controls Unitary Products