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5.
Check the phase to phase and phase to ground line voltage
to the starter/VFD, control panel (19XR6/7), power panel
(19XR3-E) and optional pumpout compressor.
6.
Ensure that fused disconnects or circuit breakers have
been supplied for all power leads to the chiller or associ-
ated equipment.
7.
Ensure all electrical equipment and controls are properly
grounded in accordance with job drawings, certified draw-
ings, 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 and inspect power panel
(19XR3-E) or control panel (19XR6/7) to ensure contrac-
tor has used the knockouts to feed the wires into the enclo-
sures and that appropriate strain relief is provided.
10. Verify all field connected wiring including option control
wiring to control panel.
11. Field-installed starters only (or for VFD units only if chiller
controls indicate ground fault), test the chiller compressor
motor and its power lead insulation resistance with a 500-v
insulation tester such as a megohmmeter. (Use a 5000-v tester
for motors rated over 600-v.) Factory mounted starters do not
require a megohm test.
a. Open the starter main disconnect switch and follow lock-
out/tagout rules.
CAUTION
If the motor starter is a solid-state starter or VFD, the motor
leads must be disconnected from the starter before an insula-
tion test is performed. The voltage generated from the tester
can damage the starter/VFD components.
CAUTION
Do not route control wiring carrying 30-v or less within a
conduit carrying 50 v or higher. Failure to observe this pre-
caution could result in electromagnetic interference in the
control wiring.
b. With the tester connected to the motor leads, take 10-sec-
ond and 60-second megohm readings as follows:
6-Lead Motor — Tie all 6 leads together and test
between the lead group and ground. Next tie the leads in
pairs: 1 and 4, 2 and 5, and 3 and 6. Test between each
pair
while
3-Lead Motor — Tie terminals 1, 2, and 3 together and
test between the group and ground.
c. Divide the 60-second resistance reading by the 10-sec-
ond 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 on a field-
installed starter 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
NOTE: Unit-mounted starters do not have to be megohm
tested.
12. Tighten all wiring connections to the plugs on the IOBs
and PIC6 HMI panel.
13. On chillers with free-standing starters, inspect the power
panel (19XR3-E) to ensure that the contractor has fed the
grounding
the
third
wires into the bottom or side of the panel. The installation
of wiring into the top of the panel can cause debris to fall
into the contactors. Clean and inspect the contactors if this
has occurred.
14. Torque all AC power terminals to specified torque.
Do not apply power unless a qualified Carrier technician is
present. Serious personal injury may result.
Carrier
Comfort
Local Equipment Network (LEN) Interface
The 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 com-
munication 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 installa-
tion 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%
1
foil shield and an outer jacket of PVC, PVC/nylon, chrome vi-
nyl, or Teflon with a minimum operating temperature range of
–4F to 140F (–20C to 60C) is required. See table below for
cables that meet the requirements.
MANUFACTURER
ALPHA
AMERICAN
BELDEN
COLUMBIA
When connecting the communication bus to a system element, a
color code system for the entire network is recommended to sim-
plify installation and checkout. For freestanding Benshaw starters
communicating via Modbus (RS-485), Carrier recommends to use
Belden 3106A communication cable.
The following color code is recommended:
SIGNAL TYPE
+
GROUND
pair.
–
Check Starter
MECHANICAL STARTER
1.
Check all field wiring connections for tightness, clearance
from moving parts, and correct connection.
2.
Check the contactor(s) to ensure they move freely. Check
all other electro-mechanical devices, such as relays, for
free movement. If the devices do not move freely, contact
the starter manufacturer for replacement components.
leads.
3.
Reapply starter control power (not main chiller power) to
check the electrical functions.
1. Third-party trademarks and logos are the property of their respective
owners.
27
WARNING
®
Network
(CCN)
CABLE NO.
2413 or 5463
A22503
8772
02525
CCN BUS
CCN TERMINAL
CONDUCTOR
CONNECTION
INSULATION COLOR
Red
Black
Black (G)
White
White (–)
and
Red (+)
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