Bard WH483, WH602 Start Up, Important Installer Note, Crankcase Heaters, High Pressure Switch

START UP

IMPORTANT INSTALLER NOTE

For improved start-up performance, wash the indoor coil with a dishwashing detergent.

CRANKCASE HEATERS

WA421 units are provided with compressor crankcase heat. WH602 and WH483 units are not provided with crankcase heat. These units utilize scroll compressors which do not require crankcase heat in this application.

The WH421 models have an insertion well-type heater located in the lower section of the compressor housing this is a self-regulating type heater that draws only enough power to maintain the compressor at a safe temperature on these units.

Some form of crankcase heat is essential to prevent liquid refrigerant from migrating to the compressor, causing oil pump out on compressor start-up and possible valve failure due to compressing a liquid.

The decal in Figure 9 is affixed to all WA421 units detailing start-up procedure. This is very important.

Please read carefully.

HIGH PRESSURE SWITCH

The WH483 and WH602 models are supplied with a remote reset high pressure switch. If tripped, this pressure switch may be reset by turning the thermostat off then back on again.

THREE PHASE SCROLL COMPRESSOR START UP INFORMATION

Scroll compressors, like several other types of compressors, will only compress in one rotational direction. Direction of rotation is not an issue with single phase compressors since they will always start and run in the proper direction.

However, three phase compressors will rotate in either direction depending upon phasing of the power. Since there is a 50-50 chance of connecting power in such a way as to cause rotation in the reverse direction, verification of proper rotation must be made. All three phase units incorporate a phase monitor to ensure proper field wiring. See the Phase Monitor" on page 15 of this manual.

Verification of proper rotation must be made any time a compressor is change or rewired. If improper rotation is corrected at this time there will be no negative impact on the durability of the compressor. However, reverse operation for over one hour may have a negative impact on the bearing due to oil pump out.

FIGURE 9

START UP LABEL

IMPORTANT

THESE PROCEDURES MUST BE FOLLOWED AT INITIAL START UP AND AT ANY TIME POWER HAS BEEN REMOVED FOR 12 HOURS OR LONGER.

TO PREVENT COMPRESSOR DAMAGE WHICH MAY RESULT FROM THE PRES- ENCE OF LIQUID REFRIGERANT IN THE COMPRESSOR CRANKCASE:

1.MAKE CERTAIN THE ROOM THERMO- STAT IS IN THE “OFF“POSITION. (THE COMPRESSOR IS NOT TO OPERATE.)

2.APPLY POWER BY CLOSING THE SYSTEM DISCONNECT SWITCH. THIS ENERGIZES THE COMPRES- SOR HEATER WHICH EVAPORATES THE LIQUID REFRIGERANT IN THE CRANKCASE.

3.ALLOW 4 HOURS OR 60 MINUTES PER POUND OF REFRIGERANT IN THE SYSTEM AS NOTED ON THE UNIT RATING PLATE, WHICHEVER IS GREATER.

4.AFTER PROPER ELAPSED TIME THE THERMOSTAT MAY BE SET TO OPER- ATE THE COMPRESSOR.

5.EXCEPT AS REQUIRED FOR SAFETY WHILE SERVICING, DO NOT OPEN SYSTEM DISCONNECT SWITCH.

7961-411

NOTE:If compressor is allowed to run in reverse rotation for several minutes, the compressor's internal protector will trip.

All three phase ZR3 compressors are wired identical internally. As a result, once the correct phasing is determined for a specific system or installation, connecting properly phased power leads to the same Fusite terminal should maintain proper rotation direction.

Verification of proper rotation direction is made by observing that suction pressure drops and discharge pressure rises when the compressor is energized.

Reverse rotation also results in an elevated sound level over that with correct rotations, as well as, substantially reduced current draw compared to tabulated values.

The direction of rotation of the compressor may be changed by reversing any two line connections to the unit.

Manual 2100-399 Page 14