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3.2.
Electrical Service
Before proceeding with the electrical connections, make certain that the volts, hertz, and phase
correspond to that specified on the unit electrical nameplate. Check to be sure the electrical
service provided by the utility company is enough to handle the additional load imposed by this
equipment.
Most units with secondary heat exchangers will require a separate power source and field
provided interconnecting wires. See Air cooled condenser and fluid coolers with individual
Installation, Operation and Maintenance Manuals.
Remote condensers will typically require one power source. Glycol systems with fluid coolers
and loose pump(s) typically require one power source for the fluid cooler and will require one
additional source for single pump or two additional sources for dual pumps. Systems where the
pump(s) are mounted and piped integral to the fluid cooler will usually require a single power
source.
3.3.
Nameplate Ratings
Refer to the unit electrical nameplate for equipment electrical requirements. The unit nameplate
is located inside the cabinet on the outside of the electrical control box door. The nameplate
includes Min. (Minimum) Circuit Ampacity (MCA) also known as wire sizing amps which indicates
the minimum required wire gauge. The Maximum Overcurrent Protection (MOP) device amps
indicates the maximum circuit breaker or fuse size required to protect the system. Max. Fuse or
Max. CKT. BKR. indicates the maximum breaker or fuse size and this information is used to size
the appropriate fuses or a Heating, Air Conditioning, and Refrigeration (HACR) type circuit
breaker. Other protection devices are not allowed based upon the product UL listing.
The facility main distribution panel which provides electrical service to the Data Aire equipment
must be provided with a manual fused disconnect switch or HACR type circuit breaker per local
and national electrical codes.
NOTE:
Do not mount a customer supplied manual fused disconnect
switch or HACR type circuit breaker to the surface of the unit.
3.4.
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.
3.5.
Voltage Tolerance
3.5.1. Three Phase Voltage Tolerance
The supply voltage to the unit for three phase operation must be within a voltage tolerance per
table below. The maximum allowable voltage phase to phase imbalance must not exceed 3%.
Voltage imbalance causes high amperage over one or several phases, which in turn leads to
overheating and possible damage. The local utility company should be contacted for correction
of improper line voltage. Deviation from ratings can cause premature failures and possibly void