Carrier 19XRV Start-Up, Operation And Maintenance Instructions Manual page 134

I General
1.0 Variable Frequency Drive (VFD) shall be designed and manu-
factured in accordance with Carrier engineering requirement
Z-420.
1.1 All field-supplied conductors and devices must be compliant,
and be installed in compliance with all applicable codes and
job specifications.
1.2 The routing of field-installed conduit and conductors and the
location of field-installed devices must not interfere with
equipment access or the reading, adjusting or servicing of
any component.
1.3 Equipment installation and all starting and control devices
must comply with details in equipment submittal drawings
and literature.
1.4 Contacts and switches are shown in the position they would
assume with the circuit deenergized and the chiller shutdown.
1.5 Warning — Do not use aluminum conductors.
1.6 Warning — Remove panel above VFD main circuit breaker
before drilling. Do not drill into any other VFD cabinet panels.
II Power Wiring To VFD
2.0 Provide a means of disconnecting branch feeder power to
VFD. Provide short circuit protection and interrupt capacity for
branch feeder in compliance with all applicable codes.
2.1 Metal conduit must be used for the power wires, from VFD to
branch feeder.
2.2 Line side power conductor rating must meet VFD nameplate
voltage and chiller full load amps (minimum circuit ampacity).
2.3 Lug adapters may be required if installation conditions dictate
that conductors be sized beyond the minimum ampacity
required. Circuit breaker lugs will accommodate the quantity
(#) and size cables (per phase) as follows.
STANDARD 65KAIC
LUG CAPACITY
VFD
(PER PHASE)
MAX INPUT
AMPS
No. of Conductor
Conductors Range
442A 3 3/0 — 500MCM
608A 3 3/0 — 500MCM
1169A 4 500 — 1000MCM
NOTES
OPTIONAL 100KAIC
LUG CAPACITY
(PER PHASE)
No. of Conductor
Conductors Range
2 400 — 500MCM
3 3/0 — 400MCM
4 500 — 1000MCM
Fig. 56 — 19XRV Field Wiring (cont)
134
If larger lugs are required, they can be purchased from the
manufacturer of the circuit breaker (Cutler-Hammer or
Square D).
2.4 Compressor motor and controls must be grounded by using
equipment grounding lug provided inside unit-mounted VFD
enclosure.
III Control Wiring
3.0 Field-supplied control conductors to be at least 18 AWG
(American Wire Gage) or larger.
3.1 Ice build start/terminate device contacts, remote start/stop
device contacts and spare safety device contacts (devices
not supplied by Carrier) must have 24 vac rating. Max current
is 60 mA, nominal current is 10 mA. Switches with gold-
plated bifurcated contacts are recommended.
3.2 Remove jumper wire between TB1-19 and TB1-20 before
connecting auxiliary safeties between these terminals.
3.3 Each integrated contact output can control loads (VA) for
evaporator pump, condenser pump, tower fan low, tower fan
high and alarm annunciator devices rated 5 amps at 115 vac
and up to 3 amps at 250 vac.
Control wiring required for Carrier to start pumps and tower fan
motors, and established flows must be provided to assure
machine protection. If primary pump, tower fan and flow control
is by other means, also provide a parallel means for control by
Carrier. Failure to do so could result in machine freeze-up or
overpressure.
Do not use control transformers in the VFD enclosure or
power panel as the power source for external or field-supplied
contactor coils, actuator motors or any other loads.
3.4 Do not route control wiring carrying 30 v or less within a con-
duit which has wires carrying 50 v or higher or along side
wires carrying 50 v or higher.
3.5 Spare 4 to 20 mA output signal is designed for controllers
with a non-grounded 4 to 20 mA input signal and a maximum
input impedance of 500 ohms.