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Fig. 33 —
Disconnect Switch and Unit
ALL UNITS
All field wiring must comply with NEC and all local
requirements. See Fig. 34-38 for wiring diagrams.
Size wire based on MCA (Minimum Circuit Amps) on the unit in
-
formative plate. See Fig. 39 and the unit label diagram for power
wiring connections to the unit power terminal blocks and equip
-
ment ground. Refer to Table 7 for maximum wire size at connec
-
tion lugs.
Provide a ground-fault and short-circuit over-current protection
device (fuse or breaker) per NEC Article 440 (or local codes). Re
-
fer to unit informative data plate for MOCP (Maximum Over-cur
-
rent Protection) device size.
NOTE: Units ordered with factory-installed HACR do not need an
additional ground-fault and short-circuit over-current protection
device unless local codes require.
Voltage to compressor terminals during operation must be within
voltage range indicated on unit nameplate. On 3-phase units, volt
-
ages between phases must be balanced within 2% and the current
within 10%. Use the formula shown below to determine the per
-
cent 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%.
All units except 208/230-v units are factory wired for the voltage
shown on the nameplate. If the 208/230-v unit is to be connected
to a 208-v power supply, the control transformer must be rewired
by moving the black wire with the
1
/
4
-in. female spade connector
from the 230-v connection and moving it to the 200-v
1
/
4
-in. male
terminal on the primary side of the transformer. Refer to unit label
diagram for additional information.
% Voltage
Imbalance
= 100 x
max voltage deviation from average voltage
average voltage
COPPER
WIRE ONLY
ELECTRIC
DISCONNECT
SWITCH
ALUMINUM
WIRE
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.
CAUTION
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage.
Operation on improper line voltage or excessive phase imbal
-
ance constitutes abuse and may cause damage to electrical
components. Such operation would invalidate any applicable
Carrier warranty.
A
B
C
MOTOR
Summary of Contents for 48LC Series
Page 5: ...5 Fig 2 Unit Dimensional Drawing Size 08 Unit ...
Page 6: ...6 Fig 2 Unit Dimensional Drawing Size 08 Unit cont ...
Page 7: ...7 Fig 3 Unit Dimensional Drawing Size 09 and 12 Units ...
Page 8: ...8 Fig 3 Unit Dimensional Drawing Size 09 and 12 Units cont ...
Page 11: ...11 Fig 6 Roof Curb Details Size 08 12 Units ...
Page 21: ...21 Fig 34 48LC 08 12 Electro mechanical Control Wiring Diagram ...
Page 22: ...22 Fig 35 48LC 08 12 RTU Open Control Wiring Diagram ...
Page 23: ...23 Fig 36 48LC 08 12 SystemVu Control Wiring Diagram ...
Page 25: ...25 Fig 38 48LC 08 12 Typical Power Wiring Diagram SystemVu Control 208 230 v Unit Shown ...
Page 61: ......