Inspect Wiring - Carrier 19XRV Start-Up, Operation And Maintenance Instructions Manual

Inspect Wiring

Do not check the voltage supply without proper equipment
and precautions. Serious personal injury may result. Follow
power company recommendations.
Do not apply any kind of test voltage, even for a rotation
check, if the chiller is under a dehydration vacuum. Insula-
tion breakdown and serious damage may result.
1. Examine the wiring for conformance to the job wiring
diagrams and all applicable electrical codes.
2. Connect a voltmeter across the power wires to the VFD
and measure the phase to phase and phase to ground
voltage. Compare this reading to the voltage rating on the
compressor and VFD nameplates.
3. Compare the ampere rating on the VFD enclosure
nameplate to the rating on the compressor nameplate.
4. The VFD must be wired to components and terminals
required for PIC III refrigeration control. Check line side
power and for control components shown on the Certified
Prints. The VFD must share control of cooler and con-
denser liquid pumps and cooling tower fans.
5. Check the phase to phase and phase to ground line
voltage to the VFD, power panel, and optional pumpout
compressor. Compare voltages against nameplate values.
6. Ensure that fused disconnects or circuit breakers have
been supplied to the VFD and optional pumpout unit.
7. Ensure all electrical equipment and controls are properly
grounded in accordance with the job drawings, certified
drawings, and all applicable electrical codes.
8. Ensure the customer's contractor has verified proper oper-
ation of the pumps, cooling tower fans, and associated
auxiliary equipment. This includes ensuring motors are
properly lubricated and have proper electrical supply and
proper rotation.
9. Tighten all wiring connections on the high and low
voltage terminal blocks in the VFD enclosure below the
control panel.
10. Inspect the power panel and VFD enclosure to ensure that
the contractor has used the knockouts to feed the wires
into the back of the enclosures. Wiring into the top of the
enclosures can allow debris to fall into the enclosures.
Clean and inspect the interior of the power panel and
VFD enclosure if this has occurred.
Do not apply power unless a qualified Carrier technician is
present. Serious personal injury may result.
Ground Fault Troubleshooting —
cedure only if ground faults are declared by the chiller controls.
Test the chiller compressor motor and its power lead
insulation resistance with a 500-v insulation tester such as a
megohmmeter.
Carrier Comfort Network
Comfort Network (CCN) communication bus wiring is
supplied and installed by the electrical contractor. It consists of
shielded, 3-conductor cable with drain wire.
bus in a daisy chain arrangement. The positive pin of each
system element communication connector must be wired to the
positive pins of the system element on either side of it. The
negative pins must be wired to the negative pins. The signal
ground pins must be wired to the signal ground pins. See
installation manual.
NOTE: Conductors and drain wire must be 20 AWG
(American Wire Gage) minimum stranded, tinned copper.
Individual conductors must be insulated with PVC, PVC/
nylon, vinyl, Teflon, or polyethylene. An aluminum/polyester
100% foil shield and an outer jacket of PVC, PVC/nylon,
chrome vinyl, or Teflon with a minimum operating tempera-
ture range of –4 F to 140 F (–20 C to 60 C) is required. See
table below for cables that meet the requirements.
element, a color code system for the entire network is recom-
mended to simplify installation and checkout. The following
color code is recommended:
Follow this pro-
63
1. Open the VFD main disconnect switch and follow
lockout/tagout rules.
The motor leads must be disconnected from the VFD
before an insulation test is performed. The voltage
generated from the tester can damage the VFD.
2. With the tester connected to the motor leads, take
10-second and 60-second megohm readings as follows:
Tie terminals 1, 2, and 3 together and test between the
group and ground.
3. Divide the 60-second resistance reading by the 10-second
reading. The ratio, or polarization index, must be one or
higher. Both the 10 and 60-second readings must be at
least 50 megohms.
If the readings are unsatisfactory, repeat the test at the
motor with the power leads disconnected. Satisfactory
readings in this second test indicate the fault is in the
power leads.
The system elements are connected to the communication
MANUFACTURER
Alpha
American
Belden
Columbia
When connecting the CCN communication bus to a system
CCN BUS
SIGNAL CONDUCTOR
TYPE INSULATION
COLOR
+ Red
Ground White
– Black
The Carrier
® Interface —
CABLE NO.
2413 or 5463
A22503
8772
02525
CCN
ICVC PLUG J1
TERMINAL
PIN NO.
CONNECTION
RED (+) 1
WHITE (G) 2
BLACK (–) 3