Carrier WeatherExpert 48N2 - Page 30

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Unit failure as a result of operation on improper line voltage or ex-
cessive phase imbalance constitutes abuse and may cause damage
to electrical components.
Determine percent voltage imbalance:
Check proper rotation of the compressors. If they rotate in reverse
change the phasing of the main power not the compressors.
NOTE: Do not depend on fan rotation for proper phasing; the
VFDs will correct for swapped phases.
Check current draw of VFD and motor for proper phase balance.
All currents at 60 Hz should be within 5% of each other and the
rated load amps or a line reactor may be required to correct for
building or grid phase shifts. Check the building supply for proper
phasing of 120 degrees.
Fig. 21 — Field Power Wiring Connections
Fig. 22 — Factory-Installed Disconnect Location (End
of Unit Shown)
Fig. 23 — Field Power Wiring Connections
for Factory-Installed Disconnect
Table 7 — Motor Limit
LEGEND NOTE: Extensive motor and electrical testing on the Carrier units has
ensured that the full horsepower range of the motor can be utilized with
confidence. Using fan motors up to the horsepower ratings shown in the
Motor Limitations table will not result in nuisance tripping or premature
motor failure. Unit warranty will not be affected.
% Voltage Imbalance = 100 x
7
457
= 1.53%
LEGEND
EQUIP — Equipment
GND — Ground
NEC — National Electrical Code
TB — Terminal Block
21
11
22
12
23
13
DISCONNECT PER NEC
EQUIP GND
TB1
POWER
WIRING
ENTRY
FACTORY-INSTALLED
DISCONNECT
HANDLE LOCATION
23
13 12 11
22 21
DISCONNECT
PER NEC
EQUIP
GND
FIELD
WIRE
FACTORY
WIRE
LEGEND
EQUIP — Equipment
GND — Ground
NEC — National Electrical Code
NOMINAL
HP
BkW MAX BHP MAX BkW
MAX AMPS (EA)
RATED
EFFICIENCY
460 V 575 V
7.5 5.6 8.6 6.39 12.0 10.0 91.7
10 7.5 11.5 8.56 14.3 12.0 91.7
15 11.2 17.3 12.89 22.0 19.0 93.0
20 14.9 22.9 17.10 28.7 23.0 93.6
25 18.7 28.7 21.41 36.3 28.4 93.6
30 22.4 34.5 25.71 41.7 36.3 94.1
40 29.8 45.9 34.27 55.0 43.8 94.1
50 37.3 57.4 42.83 71.0 52.8 94.5
60 44.8 68.9 51.41 83.0 60.5 95.0
75 59.5 86.1 64.25 101.0 80.5 95.0
100 74.6 114.8 85.67 132.0 106.0 95.4
Bhp — Brake Horsepower
BkW — Brake Kilowatts