HCFC-22 and HFC-134a should not be mixed with
air or oxygen and pressurized for leak testing. In gen-
eral,neither refrigerant should not be allowed to be pre-
sent with high concentrations of air or oxygen above
atmospheric pressures, as the mixture can undergo
combustion.
REFRIGERANT TRACER — Use an environmentally
acceptable refrigerant as a tracer for leak test procedures.
TO PRESSURIZE WITH DRYNITROGEN — Another
method of leak testing is to pressurize with nitrogen only
anduse a soap bubble solution or an ultrasonic leak detector
to determine if leaks are present. This should only be done
if all refrigerant has been evacuated from the vessel.
1. Connecta copper tube from the pressure regulator on the
cylinder to the refrigerant charging valve. Never apply
full cylinder pressure to the pressurizing line. Follow the
listed sequence.
2. Open the charging valve fully.
3. Slowly open the cylinder regulating valve.
4. Observe the pressure gage on the chiller and close the
regulating valve when the pressure reaches test level.Do
not exceed 140 psig (965 kPa).
5. Close the charging valve on the chiller. Remove the cop-
per tube if no longer required.
Repair the Leak, Retest, and Apply Standing
Vacuum Test— After pressurizing the chiller, test for
leaks with an electronic, halide leak detector, soap bubble
solution,or an ultrasonic leak detector. Bring the chiller back
to atmospheric pressure, repair any leaks found, and retest.
Afterretesting and finding no leaks, apply a standing vacuum
test, and then dehydrate the chiller. Refer to the Standing
VacuumTest and Chiller Dehydration in the Before Initial
Start-Up section, pages 43 and 47.
CheckingGuide Vane Linkage — When the chiller
is off, the guide vanes are closed and the actuator mecha-
nismis in the position shown in Fig. 36. If slack develops in
the drive chain, backlash can be eliminated as follows:
1. Withthe machine shut down and the actuator fully closed,
remove the chain guard and loosen the actuator bracket
holddown bolts.
2. Loosen guide vane sprocket adjusting bolts.
3. Pry bracket upwards to remove slack, then retighten the
bracket holddown bolts.
4. Retighten the guide vane sprocket adjusting bolts. Make
surethat the guide vane shaft is rotated fully in the clock-
wise direction in order for it to be fully closed.
CHECKINGTHE AUXILIARYSWITCH ON GUIDE VANE
ACTUATOR— The auxiliary switch used to activate the oil
reclaim system solenoids should move to the OPEN posi-
tion when the actuator is 70 degrees open. (At this point the
guide vanes should be 30 degrees open.)
TrimRefrigerant Charge — If it becomes necessary
toadjust the refrigerant charge to obtain optimum chiller per-
formance, operate the chiller at design load and then add or
removerefrigerant slowly until the difference between leav-
ingchilled water temperature and the cooler refrigerant tem-
perature reaches design conditions or becomes a minimum.
Do not overcharge.
Refrigerant may be added either through the storage tank
or directly into the chiller as described in the Charge
Refrigerant into Chiller section.
Toremove any excess refrigerant, follow the procedure in
Transfer Refrigerant from Chiller to Storage Tanksection,
Steps 1a and b, page 60.
WEEKLYMAINTENANCE
Checkthe Lubrication System — Mark the oil level
onthe reservoir sight glass, and observe the level each week
while the chiller is shut down.
If the level goes below the lower sight glass, the oil
reclaimsystem will need to be checked for proper operation.
If additional oil is required, add it through the oil drain
charging valve (Fig. 2Aor Fig. 2B). A pump is required for
adding oil against refrigerant pressure. The oil charge is
approximately 8 gallons (30 L). The added oil must meet
Carrier specifications for the 19XL. Refer to Changing Oil
Filter and Oil Changes sections on page 63.Any additional
oil that is added should be logged by noting the amount and
date.Any oil that is added due to oil loss that is not related
to service will eventually return to the sump. It must be
removed when the level is high.
A 1200-watt oil heater is controlled by the PIC to main-
tain oil temperature (see the Controls section) when the
compressor is off.The LID Status02 table displays whether
theheater is energized or not. If the PIC shows that the heater
isenergized, but the sump is not heating up, the power to the
oil heater may be offor the oil level may be too low. Check
the oil level, the oil heater contactor voltage, and oil heater
resistance.
The PIC will not permit compressor start-up if the oil
temperatureis too low. The control will continue with start-up
only after the temperature is within limits.
Fig. 36 — Guide VaneActuator Linkage
62