16
Specifications subject to change without notice.
516 01 3604 04
NOTE: TEST LEADS — Unit may be equipped with short
test leads (pigtails) on the field line connection points on
contactor C or optional disconnect switch. These leads are
for factory-run test purposes only; remove and discard be
-
fore connecting field power wires to unit connection points.
Make field power connections directly to line connection
pressure lugs only.
Fig. 27 — Disconnect Switch and Unit
ALL UNITS
All field wiring must comply with NEC and all local codes.
Size wire based on MCA (Minimum Circuit Amps) on the
unit informative plate. See Fig. 26 and the unit label diagram
for power wiring connections to the unit power terminal
blocks and equipment ground. Maximum wire size is #2/0
AWG (copper only) per pole.
Provide a ground fault and short circuit over-current protec
-
tion device (fuse or breaker) per NEC Article 440 (or local
codes). Refer to unit informative data plate for MOCP (Max
-
imum Over-Current Protection) device size.
Voltage to compressor terminals during operation must be
within voltage range indicated on unit nameplate. On
3
-
phase units, voltages between phases must be balanced
within 2% and the current within 10%. Use the formula
shown in the following example to determine the percent of
voltage imbalance.
Example: Supply voltage is 230-3-60
Determine maximum deviation from average voltage.
(AB) 227-224 = 3 v
(BC) 231-227 = 4 v
(AC) 227-226 = 1 v
Maximum deviation is 4 v.
Determine percent of voltage imbalance.
This amount of phase imbalance is satisfactory as it is below the maxi
-
mum allowable 2%.
Operation on improper line voltage or excessive phase im
-
balance constitutes abuse and may cause damage to elec
-
trical components. Such operation would invalidate any ap
-
plicable warranty.
UNITS WITHOUT FACTORY-INSTALLED NON-FUSED
DISCONNECT
When installing units, provide a disconnect switch per NEC
(National Electrical Code) of adequate size. Disconnect siz
-
ing data is provided on the unit informative plate. Locate on
unit cabinet or within sight of the unit per national or local
codes. Do not cover unit informative plate if mounting the
disconnect on the unit cabinet.
UNITS WITH FACTORY-INSTALLED NON-FUSED
DISCONNECT
The factory-installed optional disconnect switch is located in
a weatherproof enclosure located under the main control
box. The manual switch handle is accessible through an
opening in the access panel. Discard the factory test leads
(see Fig. 28). The factory disconnect is 80A disconnect.
WARNING
FIRE HAZARD
Failure to follow this warning could result in personal in
-
jury, death, or property damage.
Do not connect aluminum wire between disconnect
switch and unit. Use only copper wire.
COPPER
WIRE ONLY
ELECTRIC
DISCONNECT
SWITCH
ALUMINUM
WIRE
% Voltage
Imbalance = 100 x
max voltage deviation from average voltage
average voltage
AB = 224 v
BC = 231 v
AC = 226 v
Average Voltage =
(224 + 231 + 226)
=
681
=
227
3
3
% Voltage Imbalance = 100x
4
= 1.78%
227
IMPORTANT: If the supply voltage phase imbalance is more than 2%,
contact your local electric utility company immediately.
A
B
C
MOTOR
