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 Carri-
®
Carrier Comfort Network
Interface —
er Comfort Network (CCN) communication bus wiring is
supplied and installed by the electrical contractor. It consists of
shielded, 3-conductor cable with drain wire.
The system elements are connected to the communication
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.
MANUFACTURER
CABLE NO.
ALPHA
2413 or 5463
AMERICAN
A22503
BELDEN
8772
COLUMBIA
02525
When connecting the CCN communication bus to a system
element, a color code system for the entire network is recom-
mended to simplify installation and checkout. The following
color code is recommended:
CCN BUS
CCN
SIGNAL
CONDUCTOR
ICVC PLUG J1
TERMINAL
TYPE
INSULATION
PIN NO.
CONNECTION
COLOR
+
Red
RED (+)
1
GROUND
White
WHITE (G)
2
–
Black
BLACK (–)
3
Power Up the Controls and Check the Oil
Ensure that an oil level is visible in the compres-
Heater —
sor before energizing the controls. A circuit breaker in the
VFD energizes the oil heater and the control circuit. When first
powered, the ICVC should display the default screen within a
short period of time.
The oil heater is energized by powering the control circuit.
This should be done several hours before start-up to minimize
oil-refrigerant migration. The oil heater is controlled by the
PIC III and is powered through a contactor in the power panel.
A separate circuit breaker powers the heater and the control
circuit. This arrangement allows the heater to energize when
the main motor circuit breaker is off for service work or
extended shutdowns. The oil heater relay status (OIL HEATER
RELAY) can be viewed on the COMPRESS table on the ICVC.
Oil sump temperature can be viewed on the ICVC default
screen.
*Teflon is a registered trademark of Dupont.
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