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3.0 ELECTRICAL CONNECTIONS
Before proceeding with the electrical connections, make certain that the volts,
hertz and phase correspond to that specifi ed on the unit electrical nameplate. Use
copper conductors only.
3.1 Electrical Service
Check to be sure the service provided by the utility is suffi cient to handle the additional load imposed
by this equipment. Indoor package units have a single power source. Indoor split units typically
have a single power source but can also be provided with separate sources. Field-provided,
interconnecting control wires are also required. Units with outdoor secondary heat exchangers
will require a separate power source and fi eld-provided, interconnecting control wires as well. See
section 3.5 below.
Remote outdoor condensers and condensing units require one power source. Glycol systems
with fl uid coolers and loose pump(s) typically require one power source for the fl uid cooler and will
require one additional source for a single pump or two additional sources for dual pumps. Systems
where the pump(s) are mounted and piped integral to the fl uid cooler will usually require a single
power source.
3.2 Nameplate Ratings
Refer to the unit electrical nameplate for equipment electrical requirements. Minimum Circuit
Ampacity, also known as Wire Sizing Amps, will dictate the minimum required wire gage. Maximum
Overcurrent Protection Device amps will dictate the maximum circuit breaker or fuse size.
3.3 Grounding
The unit cabinet must have an uninterrupted true earth ground. An electrical ground wire of adequate
size must be connected to the ground lug provided inside the main electrical box.
3.4 Voltage Tolerance
The supply voltage to the unit must be within tolerance of -5%, +10% for 208-230 volt, +/- 10% for
277 volts. The local utility company should be contacted for correction of improper line voltage.
Deviation from voltage ratings can cause premature failures and possibly void unit warranty.
Check the wiring connections in the unit control panel to ensure they are tight. Screw
terminals may become loose in transit. tightening of wiring connections is the responsibility
of the installing contractor.
3.5 Auxiliary Control Wiring
For secondary heat exchangers (condensers and fl uid coolers) connect two 18 gage wires from the
electrical box of the indoor evaporator to the electrical box of the remote heat exchanger. Refer to the
wiring diagrams located int he electrical control panel of each unit. On most remote heat exchangers
the terminals will also be #39 and #40. All control wiring on Data Aire equipment is 24 VAC.
Condensing units (compressors mounted in condenser) typically require more wires. Refer to wiring
diagrams in the units.
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