AAON CC-063 - Manual (Page 14)

14
Route power and control wiring through the
utility entries on the sides of the unit. It is
recommended not to run power and control
signal wires in the same conduit. If the
control wires are run inside the same conduit
as the power wiring use 600 volt wire, or as
required by applicable codes.
Size supply conductors based on the unit
MCA rating. Supply conductors must be
rated a minimum of 75°C.
Protect the branch circuit in accordance with
code requirements. The unit must be
electrically grounded in accordance with
local codes, or in the absence of local codes,
the
current National Electric Code,
ANSI/NFPA 70 or the current Canadian
Electrical Code CSA C22.1.
Note: Units are factory wired for 208V,
230V, 460V or 575V. In some units, the
208V and 230V options may also be
provided
in single or three phase
configurations. The transformer
configuration must be checked by a
qualified technician prior to startup.
Wire power leads to the unit terminal block
or compressor contactor. All wiring beyond
this point has been done by the manufacturer
and cannot be modified without effecting the
unit's agency/safety certification.
All units require field supplied electrical
overcurrent and short circuit protection.
Device must not be sized larger than the
Maximum Overcurrent Protection (MOP)
shown on the unit nameplate.
Codes may require a disconnect switch be
within sight of the unit.
It is recommended that the field installed
overcurrent protection or disconnect switch
not be installed on the unit.
Supply voltage must be within the min/max
range shown on the unit nameplate.
Available short circuit current should not
exceed the short circuit current rating
(SCCR) shown on the unit nameplate.
Three phase voltage imbalance will cause
motor overheating and premature failure.
The maximum allowable imbalance is 2.0%.
Voltage imbalance is defined as 100 times
the maximum deviation from the average
voltage divided by the average voltage.
Example:
(221V+230V+227V)/3
= 226V, then
100*(226V-221V)/226V = 2.2%, which
exceeds the allowable imbalance.
Check voltage imbalance at the unit
disconnect switch and at the compressor
terminal. Contact your local power company
for line voltage corrections.
Installing contractor must check for proper
motor rotation and check fan motor
amperage listed on the motor nameplate is
not exceeded.
Rotation must be checked on all
MOTORS AND COMPRESSORS of
three phase units. Condenser fan
motors should be checked by a
qualified service technician at startup
and any wiring alteration should only
be
made at the unit power
connection.
CAUTION
Three phase voltage imbalance will
cause
motor overheating and
premature failure.
CAUTION