Inspect Water Piping —
Refer to piping diagrams pro-
vided in the certified drawings, and the piping instructions
in the 19EF Installation Instructions manual. Inspect the pip-
ing to the cooler and condenser. Be sure that flow directions
are correct and that all piping specifications have been met.
Piping systems must be properly vented, with no stress on
waterbox nozzles and covers. Water flows through the cooler
and condenser must meet job requirements. Measure the pres-
sure drop across cooler and across condenser.
Water must be within design limits, clean, and treated
to ensure proper machine performance and reduce the
potential of tubing damage due to corrosion, scaling, or
erosion. Carrier assumes no responsibility for chiller dam-
age resulting from untreated or improperly treated
water.
Check Relief Devices —
Be sure that relief devices
have been piped to the outdoors in compliance with the lat-
est edition of ANSI/ASHRAE Standard 15, latest edition,
and applicable local safety codes. Piping connections must
allow for access to the valve mechanism for periodic inspec-
tion and leak testing.
19EF relief valves are set to relieve at the 18 psig
(124 kPa) machine design pressure.
Inspect Wiring
Do not check voltage supply without proper equipment
and precautions. Serious injury may result. Follow power
company recommendations.
Do not apply any kind of test voltage, even for a rota-
tion check, if the machine is under a dehydration vacuum.
Insulation breakdown and serious damage may result.
1. Examine wiring for conformance to job wiring dia-
grams and to all applicable electrical codes.
2. On low-voltage compressors (600 v or less) connect volt-
meter across the power wires to the compressor starter
and measure the voltage. Compare this reading with the
voltage
rating
on
the
compressor
and
starter
nameplates.
3. Compare the ampere rating on the starter nameplate with
the compressor nameplate. The overload trip amps must
be 108% to 120% of the rated load amps.
4. The starter for a centrifugal compressor motor must con-
tain the components and terminals required for PIC re-
frigeration control. Check certified drawings.
5. Check the voltage at the following components and com-
pare to the nameplate values: oil pump contact, and power
panel.
6. Be sure that fused disconnects or circuit breakers have
been supplied for the oil pump, and power panel.
7. Check that all electrical equipment and controls are prop-
erly grounded in accordance with job drawings, certi-
fied drawings, and all applicable electrical codes.
8. Make sure that the customer’s contractor has verified
proper operation of the pumps, cooling tower fans, and
associated auxiliary equipment. This includes ensuring
that motors are properly lubricated and have proper elec-
trical supply and proper rotation.
9. Test the machine 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.)
a. Open the starter main disconnect switch and follow
lockout/tagout rules.
If the motor starter is a solid-state starter, the mo-
tor leads must be disconnected from the starter be-
fore an insulation test is performed. The voltage
generated from the tester can damage the starter
solid-state components.
b. With the tester connected to the motor leads, take
10-second and 60-second megohm readings as
follows:
6-Lead Motor — Tie all 6 leads together and test be-
tween the lead group and ground. Next tie leads in
pairs, 1 and 4, 2 and 5, and 3 and 6. Test between
each pair while grounding the third pair.
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-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 on a field-installed starter are unsat-
isfactory, repeat the test at the motor with the power
leads disconnected. Satisfactory readings in this sec-
ond test indicate the fault is in the power leads.
10. Tighten up all wiring connections to the plugs on the
SMM, 8-input, and PSIO modules.
11. Ensure that the voltage selector switch inside the power
panel is switched to the 115-v setting.
12. Inspect the power panel to ensure that the contractor has
fed the wires into the bottom of the panel. Wiring into
the top of the panel can cause debris to fall into the con-
tactors. Clean and inspect the contactors if this has oc-
curred.
Carrier Comfort Network Interface —
The
Carrier Comfort Network (CCN) communication bus wiring
is supplied and installed by the electrical contractor. It con-
sists 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 sig-
nal ground pins must be wired to signal ground pins.
Fig. 25 — Dehydration Cold Trap
40
Содержание 19EF Series
Страница 10: ...Fig 5 19EF Controls and Sensor Locations cont 10...
Страница 13: ...Fig 12 19EF Menu Structure 13...
Страница 14: ...Fig 13 19EF Service Menu Structure 14...
Страница 38: ...Fig 24 19EF Leak Test Procedures 38...
Страница 69: ...Fig 36 Electronic PIC Controls Wiring Schematic 69...
Страница 70: ...Fig 36 Electronic PIC Controls Wiring Schematic cont 70...
Страница 71: ...Fig 37 Machine Power Panel Starter Assembly and Motor Wiring Schematic 71...
