Start Up; Application; Important Installer Note; High And Low Pressure Switch - Bard WG Series Installation Instructions Manual

These units require R-410A refrigerant and Polyol Ester
oil.

Application

1. Use separate service and manufacturing
equipment to avoid cross contamination of oil and
refrigerants.
2. Use recovery equipment rated for R-410A
refrigerant.
3. Use manifold gauges rated for R-410A (800
psi/250 psi low).
4. R-410A is a binary blend of HFC-32 and HFC-
125.
5. R-410A is nearly azeotropic—similar to R-22 and
R-12. Although nearly azeotropic, charge with
liquid refrigerant.
6. R-410A operates at 40-70% higher pressure than
R-22, and systems designed for R-22 cannot
withstand this higher pressure.
7. R-410A has an ozone depletion potential of zero,
but must be reclaimed due to its global warming
potential.
8. R-410A compressors use Polyol Ester oil.
9. Polyol Ester oil is hygroscopic; it will rapidly absorb
moisture and strongly hold this moisture in the oil.
10. A liquid line dryer must be used—even a deep
vacuum will not separate moisture from the oil.
11. Limit atmospheric exposure to 15 minutes
MAXIMUM.
12. If compressor removal is necessary, always plug
compressor immediately after removal. Purge with
small amount of nitrogen when inserting plugs.

Important Installer Note

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

High and Low Pressure Switch

All models covered by this manual are supplied with
a remote reset high pressure switch and low 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% 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" section
on page 34.
Verification of proper rotation must be made any time a
compressor is changed 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 1 hour may have a negative
impact on the bearing due to oil pump out.
NOTE: If compressor is allowed to run in reverse
rotation for several minutes, the compressor's
internal protector will trip.
All three phase ZPS compressors are wired identically
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.

START UP

Manual 2100-587J
Page 41 of 59