Installation
21
2.6
Electrical Connections
Each unit is shipped from the factory with all internal wiring completed. All power, control wiring
and ground connections must be made in accordance with the National Electrical Code and local
codes. Refer to equipment nameplate regarding wire size and circuit protection requirements. Refer to
Figures 5
,
7
and
8
and electrical schematic (reference
Figures 9
through
11
) when making
connections. A manual electrical disconnect switch should be installed within 5 feet (1.6m) of the unit
in accordance with codes.
NOTICE
Risk of incorrect phase sequencing. Can cause equipment damage.
Three-phase power must be connected to the unit line voltage terminals in proper sequence so
that the scroll compressor rotates in the correct direction.
The three-phase scroll compressor requires proper phasing to ensure correct motor rotation. The
component connections have been phase synchronized at the factory. Power phasing should be
changed only at the line voltage supply to the unit. To change phasing, switch any two power leads to
the unit. Observe system pressures to determine whether the unit is operating properly.
NOTICE
Risk of compressor slugging. Can cause equipment damage.
Apply power to condenser 8 hours before operating the system. This time is required to allow
liquid refrigerant to be driven out of the compressor. This is especially important at low
ambient temperatures. The compressor crankcase heater is energized as long as power is
supplied to the unit.
2.6.1 Low-Voltage Control Wire Connections
Field-supplied four-wire control connection (10-wire on 8-ton units) is required between the outdoor
condensing unit and the evaporator. Refer to
Figures 5
,
7
and
8
and to unit electrical schematic and
Figures 9
through
11
.
!
WARNING
Risk of electric shock. Can cause injury or death.
Disconnect all local and remote electric power supplies before working within. Use a
voltmeter to be sure power is turned off before making any electrical connections.
Table 13
Design refrigerant pressures
Suction
53 - 95 PSIG
(365 to 655 kPa)
Discharge
(At Design Ambient)
280 psig (1930 kPa)
High-Pressure Cutout
400 psig (2760 kPa)
Table 14
Application limits
Input voltage
Dry Bulb Air Temperature at Condenser
Minimum
Maximum
Minimum
Maximum
-10%
+10%
-30°F (-34°C)
115°F (46°C) Std
Ambient & Quiet-Line
-5% 208/230V
single-phase
125°F (52°C)
High Ambient Models
Summary of Contents for PFH014A-L
Page 1: ...Liebert Prop Fan Condensing Unit User Manual 50 60Hz ...
Page 35: ......