Specifications

10 Cat 604-3
Electrical Data
Electrical Data
Electrical Notes
1 Units are available for 460 or 440 to 480 VAC at 60 Hz.
2 Wiring, fuse and wire size must be in accordance with
the National Electric Code (NEC).
3 Important: Voltage unbalance not to exceed 2%.
Power Wiring
Use only copper supply wires with ampacity based on 75°C
conductor rating. Connections to terminals must be made with
copper lugs and copper wire.
Lug size range is: (3) 3/0 AWG - 500 kc mil.
Power Factor Correction Capacitors
Do not use power factor correction capacitors with(WME
chillers. Doing so can cause harmful electrical resonance in the
system. Correction capacitors are not necessary since VFDs
inherently maintain high power factors
Short Circuit Current Ratings
The standard short circuit rating is 35kA for 460 V. Optional
high short circuit current ratings are available for 65kA, and
100kA with a matching circuit breaker.
The optional circuit breaker must be sized to meet these
ratings.
3-Phase vs. 6-phase Motors
WME 500 motors are designated as M2 or M3.
• "M2 motors are standard 3-phase and the VFD performs
similar to a 6-pulse drive.
• "M3 motors are 6-phase (connected to a 3-phase power
supply) and the VFD performs similar to a 12-pulse drive.
They provide increased protection against harmonic
distortion, but are not required on most applications.
WME 700 motors are 6-phase and designated as M4. The VFD
performs similar to a 12-pulse drive.
Notes for field wiring diagram
1 All line-side wiring must be in accordance with the NEC
and be made with copper wire and copper lugs only.
2 A customer furnished 24 to 240 Vac power for alarm
relay coil may be connected at J18. Maximum rating of
the alarm relay coil is 25 VA.
3 Remote on/off control of unit can be accomplished by
connecting a set of isolated dry contacts at J25.
4 If field supplied pressure differential flow switches are
used, they must be installed across the vessel and not the
pump. They must provide isolated dry contacts at J27.
5 An optional customer supplied 25 VA maximum coil
rated, chilled water pump relay (one or two) may be
wired as shown. This option will cycle the chilled water
pump in response to chiller demand.
6 The condenser water pump must cycle with the unit. A
customer supplied 25 VA maximum coil rated,
condenser water pump relay (one or two) must be wired
as shown. Units used in a free-cooling application must
have condenser water above 50°F before starting.
7 Optional customer supplied 25 VA maximum coil rated
cooling tower fan relays may be wired as shown. This
option will cycle the cooling tower fans as prescribed by
the tower control set points.
8 External 4-20mA signals can be wired to J23 for leaving
(chilled) water reset and to J26 for demand limit.