Charge Refrigerant; Maintenance; Weekly Maintenance; Check Oil Level - Carrier 17DA Start-Up, Operation And Maintenance Instructions Manual

2. Open valves 1, 2, 5, 6, 7, and 12.
3. Close valves 3, 4, 8, 9, 10 ,11, and 13.
Valve 1 2 3 4
Condition O O C C O O O C C
4. Operate the pumpout compressor (control switch in the
ON position).
5. When all of the liquid refrigerant has been removed from
the storage tank, stop the pumpout compressor and close
valves 1, 2, 5, 6, 7, and 12 (all valves closed).
6. Open valve 10 and plugged drain connection 14. Drain
water and impurities. Do not allow storage tank pressure
to drop below 0 psig.
7. Close valve 10 and plugged drain connection 14.
8. If, after distilling the refrigerant, there is excess refriger-
ant in the cooler over the normal operating charge, then
return the excess to the storage tank. Follow the proce-
dure Transfer Refrigerant from Machine to Storage Tank
on page 12.
CHARGE REFRIGERANT — The pumpout unit can aid in
charging refrigerant into a dehydrated machine. Perform the
following procedure. See Fig. 4 for valve numbers.
1. Follow the procedure for Machine and Storage Tank
Evacuation (No Refrigerant in System) on page 11 to re-
move any non-condensable gases, if present.
2. Using temporary charging lines, connect the vent of the
refrigerant supply cylinder to valve 13 and the cylinder
liquid drain to valve 10. Purge the lines as final connec-
tion is made to the valves.
3. Open valves 2, 4, 5, 6, 7, 10, and 13.
4. Close valves 1, 3, 8, 9, 11, and 12.
Valve 1 2 3 4
Condition C O C O O O O C C
5. Drain any remaining liquid by raising cylinder pressure
above storage tank pressure. Close valve 4 and operate
pumpout compressor with control switch in ON position.

MAINTENANCE

The primary controls, both operating and safety are now in-
corporated into the programmable logic controller (PLC)
which is incorporated into the chiller main control panel. Cus-
tomer specifications may require some or all of the sensors and
safeties to be duplicated by mechanical switched. For this rea-
son both types of sensors and safeties will be covered in the fol-
lowing procedures.

Weekly Maintenance

CHECK OIL LEVEL — Mark edge of sight glass at normal
oil level using grease pencil. Record date and amount of oil
added in refrigeration log.
CHECK PURGE FREQUENCY — Operate the purge only
when there is air in the system as indicated by the pressure in
the purge chamber when the machine is in operation. When
purge chamber pressure is within 8 psid of condenser pressure,
the vent valve can be opened to bleed air from the chamber.
Close the valve when the differential is higher than 16 psid.
WATER IN PURGE WATER CHAMBER —
R-22 and R-134a hold a greater percentage of water in the liq-
uid state than in the vapor state. As a result, a typical condens-
ing purge does not separate water from refrigerant. Alternate
methods such as refrigerant analysis are used to detect water in
these refrigerants.

Yearly Maintenance

NOTE: The primary controls, both operating and safety, are
now incorporated into the PLC, which is incorporated into the
5 6 7 8 9 10 11 12
C C O
5 6 7 8 9 10 11 12
O C C
Refrigerants
chiller main control panel. Customer specifications may
require some or all of the sensors and safeties to be duplicated
by mechanical switches. For this reason both types of sensors
and safeties will be covered in the following procedures.
13
C
CHECK/CALIBRATE WATER TEMPERATURE SEN-
SORS — The water temperature sensors are located in the out-
let piping near the water nozzles.
1. Each sensor should be compared against a calibrated sen-
sor in a calibration bath or dry block calibrator.
2. Compare the reading of the calibrated sensor with the
temperature reading on the PLC screen. Replace or cali-
brate the sensor as required.
3. Confirm that any set points on the PLC match the recom-
mended alarm or trip points for the chiller.
CHECK REFRIGERANT LOW-PRESSURE CUTOUT —
The primary low-pressure cutout will be a function of the PLC
and the pressure will be transmitted to the PLC from a trans-
ducer. An optional mechanical secondary switch may also be
installed which will send an open-closed signal to the PLC.
1. Compare the reading of the cooler pressure transducer
with a test gage and/or the condenser pressure transducer
when the machine is not in operation. Confirm that the
correct cutout pressure is configured in the PLC.
2. The chilled water low-temperature cutout set point must
be temporarily set low enough that the refrigerant low-
pressure cutout will react first. A mechanical low chiller
water temperature switch should be jumpered for the du-
ration of the test.
3. Start the machine and observe both chilled water temper-
ature and refrigerant temperature.
4. Slowly reduce the chilled water temperature control
point. Watch the thermometer in the leaving chilled water
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line and/or the leaving chilled water temperature display
O on the PLC screen. Do not allow chilled water tempera-
ture to drop below 35 F.
5. The machine should shut down when refrigerant temper-
ature reaches one degree below design suction tempera-
ture or 28 F (-2.22 C) minimum (chilled water duty).
6. Restore the chilled water low-temperature cutout to its
normal set point. Remove the jumper on the mechanical
chilled water low-temperature cutout switch.
CHECK CONDENSER HIGH-PRESSURE CUTOUT —
This PLC function and optional mechanical pressure switch
senses condenser gas pressure and shuts down the compressor
when the condenser pressure exceeds 165 psig (1138 kPa) for
R-134a or 275 psig (1896 kPa) for R-22. Do not attempt to test
this safety by forcing the condensing pressure to rise during
machine operation.
1. Compare the reading of the condenser pressure transduc-
er with a test gage and/or the cooler pressure transducer
when the machine is not in operation. Confirm that the
correct cutout pressure is configured in the PLC.
2. To check a mechanical cutout switch, first turn off the
control power.
3. Use an air or nitrogen supply which can be regulated to
the desired pressure.
4. Check the control with an ohmmeter to determine if the
switch has opened when the desired pressure is reached.
Adjust as necessary.
CHECK AUXILIARY OIL PUMP CONTROL — The pur-
pose of the auxiliary oil pump is to take over the job of supply-
ing lubricating oil at the required pressure to the bearings and
the seal in the event that the main oil pump loses pressure. The
auxiliary oil pump should start before the machine trips on low
oil pressure. The pressure being measured is the differential
pressure between the machine internal pressure on the
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