Operating instructions
40
c. The detector is connected to the motor wires,
measure the values in megohms every 10 and 60
seconds as follows:
- Six-lead motor: Tie all the leads together and
test the insulation referred to earth. Then tie
the leads in pairs, 1 and 4, 2 and 5, 3 and 6.
Test between each pair while earthing the
third pair.
- Three-lead motor: Tie terminals 1, 2, and 3
together and test the insulation referred to
earth.
- Divide the 60-second resistance reading by the
10-second reading. The ratio, or polarisation
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 leads.
The 19XR compressor holds approximately 30 l of oil for
frame 3 compressors; 38 l of oil for frame 4 compressors and
67.8 l for frame 5 compressors. The chiller will be shipped
with oil in the compressor. When the sump is full, the oil
level should be no higher than the middle of the upper
sight glass, and minimum level is the bottom of the lower
sight glass. If oil is added, it must meet Carrier’s specification
for centrifugal compressor usage as described chapter 7.3.5
“Oil changes”. Charge the oil through the oil charging
valve, located near the bottom of the transmission housing
(refer to Fig. 2 - “19XR machine components”). The oil
must be pumped from the oil container through the
charging valve due to higher refrigerant pressure. The
pumping device must be able to lift from 0 to 1380 kPa or
above unit pressure. Oil should only be charged or removed
when the chiller is shut down. The oil cylinder must not be
opened until charging begins. Only use new oil cylinders.
Ensure that an oil level is visible in the compressor before
energizing controls. A circuit breaker in the starter 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 mini-
mize oil-refrigerant migration. The oil heater is controlled
by the PIC and is powered through a contactor in the
control box. The oil heater relay status can be viewed on
the Status02 table on the ICVC. Oil sump temperature can
be viewed on the ICVC default screen.
WARNING: Do not check voltage supply without proper
equipment and precautions. Serious injury may result.
CAUTION: Do not apply any kind of test voltage, even
for a rotation check, if the chiller is under a dehydration
vacuum. Insulation breakdown and serious damage may
result.
1. Examine wiring for conformance to job wiring diagrams
and to all applicable electrical codes.
2. Check that the voltage(s) applied to the machine agree
with those on the component name plates. In particular:
- Compressor
- Compressor starter
- Control circuit transformers
- Oil pump
- Heater(s)
For low-voltage machines the check can simply be made
with a voltmeter.
3. Check that all electrical equipment and controls are
properly grounded in accordance with job drawings,
certified drawings, and all applicable electrical codes.
Make sure that the customer’s contractor has verified
proper operation of the pumps, cooling tower fans,
and associated auxiliary equipment.
4. Ensure that all power connections are tight.
5. Tighten up all wiring connections to the plugs on the
ISM and CCM modules.
6. The bus cable between the CCM and the ISM modules
will be supplied by the installer (refer to chapter 3.6.8
“Carrier Comfort Network interface”).
7. On chillers with wiring entering and leaving the cabinet
from the top debris can fall onto the contactors. Check
and clean the contactors if necessary.
The checks below are not required for 19XRV machines.
But they are replaced by additional checks. Please refer
to the appendix starting with chapter 8.
8. Compare the ampere rating on the starter nameplate
with the compressor nameplate. They must agree with
the thermal protection of the Carrier ISM board to
ensure that the overload trip current (OLTA) is not
be more than 108% of the rated load current.
9. The starter must include correctly assigned components
and terminals required for the unit PIC control. Check
the certified plans.
10. Check that the anti-short-circuit protections have
been installed upstream of the compressor power
supply circuits.
11. Check the compressor motor and power supply cable
insulation resistance: Use a 500 V insulation controller
(megohmmeter) for machines with a nominal voltage
below 1000 V. Use a 5000 V insulation controller for
compressor motors with a voltage above 1000 V:
a. Disconnect the power supply and observe the
usual applicable precautions.
b. Disconnect the motor supply wires at the starter
terminals.