York K5EU090A50A Expansion Valve Bulb, Drain Connection, Supply AIR Blower Adjustment

550.39-N4YI

Before brazing the refrigerant lines to these connections, remove the short panel from the unit frame and slide it (along with the grommets) onto the refrigerant lines. Af- ter the brazed joints have cooled, slide the panel back into place and secure it to the unit frame.

NOTE: These units can only be piped from one side of the unit.

EXPANSION VALVE BULB

On KEU090 units the expansion valve bulb must be fas- tened in a 4 o'clock position to the suction line outside the cabinet after the piping connections have been made.

On KEU120 units fasten the expansion valve bulb on the suction header 8" (203mm) below the top of the header and adjacent to the coil.

Use the clamps provided with the valve to secure the bulb in position.

DRAIN CONNECTION

The drain line MUST be trapped because the coil is lo- cated on the negative side of the supply air blower. It must also be protected from freezing temperatures.

A 7 8" (22.2mm) OD stub connection is provided within the cabinet on both ends of the condensate drain pan for either left hand or right hand piping connections. Refer to Figure 5 for recommended drain piping.

The drain line is located on the same end of the coil sec- tion as the refrigerant connections. The line should be in- sulated where moisture drippage will be objectionable or cause damage to the area. Seal the unused drain con- nection with a suitable mastic.

(76)

(64)

FIG. 5 - RECOMMENDED DRAIN PIPING

The 3" (76mm) dimension must equal or exceed the negative static pressure developed by the supply air blower. If it does not, condensate will not drain properly and may overflow the drain pan. The trap must be at least 212" (63mm) deep to maintain a water seal under all oper- ating conditions, especially during blower start-up.

NOTE: Refer to Figure 9 for minimum clearance require- ments.

SUPPLY AIR BLOWER ADJUSTMENT

The RPM of the supply air blower will depend on the re- quired airflow, the unit accessories and the static resis- tances of both the supply and the return air duct systems. With this information, the RPM for the supply air blower can be determined from the blower perform- ance in Table 4.

Knowing the required blower RPM and the blower motor HP, the setting (turns open) for the supply air motor pulley can be determined from Table 3.

Each motor pulley has:

1.A threaded barrel with two flats (or notched recesses) 180 degrees apart.

2.A movable flange with one set screw.

After the movable flange has been rotated to the proper number of “turns open”, the set screw should be tight- ened against the flat on the barrel to lock the movable flange in place. If the pulley includes a locking collar, the locking collar must be loosened to adjust the setting of the movable flange.

Note the following:

1.The supply airflow must be within the limitations shown in Table 1.

2.All pulleys can be adjusted in half-turn increments.

3.The tension on the belt should be adjusted for a deflection

of 316" (5mm) per foot (305mm) of belt span with an applied force of approximately 3 lbs (1.4kg). This adjustment is made by moving the blower motor mounting plate. Refer to Figure 6. Turning the adjustment bolt (B) moves the motor mounting plate up or down. Note - Never loosen the two nuts (C). Four hex nuts (A) have to be loosed to move the mounting plate and retightened after the mounting plate has been moved to the proper position.

4.All pulleys are factory aligned.

5.All supply air motor pulleys are factory set at three “turns open.”

After the supply air blower motor is operating, adjust the resistances in both the supply and the return duct sys- tems to balance the air distribution throughout the condi- tioned space. The job specifications may require that this balancing be done by someone other than the equip- ment installer.

To check the supply air airflow after the the initial balancing has been completed:

1.Drill two holes 516" (8mm) dia. in the side panel as shown in Figure 8.

2.Insert at least 8" (200mm) of 14" (6.3mm) O.D. tubing into each of these holes for sufficient penetration into the air flow on both sides of the evaporator coil.

NOTE: The tubes must be inserted and held in a position per- pendicular to the air flow so that velocity pressure will not affect the static pressure reading.

6 Unitary Products Group