(Mar, 2012)
Compact CWE Series Installation, Operation & Maintenance Manual
Air Technology Systems, Inc.
2-11
2.8 Utility Connections
2.8.1 Main Power
The standard
Compact CWE
product offering is avail-
able in a 460 VAC three-phase confi guration. As an
option, 575 VAC units are available upon request.
It is important that the unit nameplate be examined
to determine the operating voltage, frequency and
phase of the system (see Figure 17). The nameplate
also provides the full load amps (FLA), the current
the unit will draw under full design load, the mini-
mum circuit ampacity (MCA) for wire sizing, and the
maximum fuse or HACR (Heating, Air Conditioning,
Refrigeration) breaker size (MAX FUSE/CKT BKR)
for circuit protection. The unit’s nameplate is located
inside the cabinet, within the electrical box.
Figure 17- Sample Nameplate
NOTE
If the nameplate states MAX FUSE/CKT BKR, it
is required to use fuses or a HACR type circuit
breaker to protect the system. Other protec-
tion devices are not allowed based upon the
product listing.
The unit is provided with terminals for all required
fi eld-wiring. Refer to the electrical schematic supplied
with the unit when making the power and control
fi eld-wiring connections. It is important to identify the
options that were purchased with the unit in order to
confi rm which fi eld connections are required.
WARNING
Verify power is turned off before making
connections to the equipment.
NOTE
All wiring must conform to local and national
electrical code requirements. Use of copper
conductors only is required. Wiring terminations
may become loose during transit of the equip-
ment; therefore, it is required to verify that all
wiring terminations are secure.
CAUTION
Improper wire connections may result in damage
to the unit.
It is important to verify that the main power supply
coincides with the voltage, phase and frequency infor-
mation specifi ed on the system nameplate. The supply
voltage measured at the unit must be within ±10% of
the voltage specifi ed on the system nameplate.
Downfl ow units are provided with pilot holes for the entry
of the main power and control fi eld-wiring. These pilot
holes are located in the fan shelf. These holes may be
enlarged to properly fi t the connector. A label stating
“MAIN POWER INPUT” is in close proximity. For upfl ow
units with top piping, pilot holes for entry of power and
control wiring are located in the top of the cabinet. For
upfl ow units without top piping, entrance holes need to
be drilled in the cabinet fl oor or in a side wall. See the
installation drawing provided with your unit for recom-
mended entrance hole sizes and locations.
Terminate the main power wires at the line side of
the main power disconnect switch, located within the
electric box (see Figure 18). A separate equipment
ground lug is provided within the electrical box for
termination of the earth ground wire.
