Emerson PFH020A-L, User Manual

Page: 39 / 117

Site Preparation and Installation
Liebert
®
Mini-Mate2
™
32
5.4.4 Electrical Connections
Each unit is shipped from the factory with internal wiring completed. Refer to the electrical schematic
when making connections. Electrical connections to be made at the installation site are:
• Power supply to each ceiling unit.
• Control wiring between the evaporator unit and outdoor condensing unit, if applicable.
• Control the wiring between the control panel (wall box) and the evaporator unit control board.
Power Connections
All power and control wiring and ground connections must be in accordance with the National
Electrical Code and local codes. Refer to the unit’s serial tag data for electrical requirements.
Voltage supplied must agree with the voltage specified on the unit name plate. If a field-supplied
disconnect switch is required, it may be bolted to the ceiling unit, but not to any of the removable
panels. This would interfere with access to the unit. Make sure that no refrigerant lines are
punctured when mounting the disconnect switch.
Route the electrical service conduit through the hole provided in the cabinet and terminate it at the
electric box. Make connections at the factory terminal block or disconnect switch, L1, L2, (L3).
Connect earth ground to lug provided. For 208 VAC applications, the low-voltage transformer tap
must be changed. Refer to the electrical schematic.
Wall Box Control Connections
A four-conductor (thermostat type) field-supplied wire must be connected between the evaporator
control board and the wall box display. See Figures 22 , 28 and 29 for electrical connections.
Condensing Unit Control Connections
A field-supplied four-conductor (thermostat type) wire (24VAC) must be connected between the
evaporator and the outdoor condensing unit, whenever a split system condensing unit is used. Control
wiring must be installed in accordance with NEC and local codes.
Glycol-Cooled Control Connections
Glycol-cooled units require a field-supplied two-conductor (thermostat type) wire connection between
the evaporator unit and the drycooler. Control wiring must be installed in accordance with NEC and
local codes.
!
WARNING
Arc flash and electric shock hazard. Open all local and remote electric power disconnect
switches and wear protective equipment per NFPA 70E before working within the electric
control enclosure.
Failure to comply can cause injury or death.
Unit contains hazardous voltage electric power. Line side of factory disconnect remains
energized when factory disconnect is Off.
!
WARNING
Risk of loose electrical connections. Can cause overheating of wire, smoke and fire resulting in
building and equipment damage, injury or death .
Use copper wiring only. Verify that all connections are tight.