Filter Drier Replacement; Motor; Determining Correct Refrigerant Charge Level; Refrigerant Charge Level - York MILLENNIUM YS Manual

Maintenance
3. Follow the instructions for changing the single
oil filter beginning at step #3.
4. This can now be the idle filter and the chiller
can be operated with the current oil filter.

FILTER DRIER REPLACEMENT

The filter driers should be changed annually or when
excessive amount of oil is indicated in the refrigerant
charge.
When the filter driers require changing the chiller must
be shut off.
1. Close the (5) hand isolation valves identified in sche-
matic drawing, Figure 22.
2. Carefully remove the insulation on the (2) filter dri-
ers located on the eductor block.
3. Relieve the pressure from the circuit using the pres-
sure access fitting located on the side of the educ-
tor block. Connect a refrigeration pressure hose to
the pressure access port and drain the oil and re-
frigerant into a suitable refrigerant recovery con-
tainer.
4. Loosen the Rota-Lock® Nuts at each end of the (3)
filter driers. Remove the filter driers.
5. Teflon® seal washers are used to seal the filter drier
connections. These washers must be replaced when
the filter driers are replaced.
6. Tighten the Rota-Lock® Nuts at each end of the
three filter driers to a torque of 60 ft-lb.
7. Evacuate the air from the oil filter to 500 microns
psig.
8. Open the five hand isolation valves. The chiller is
now ready to be placed back into service.

MOTOR

Inspect the motor at regular intervals. Keep the motor
clean and vent openings clear. Follow the original motor
manufacturer recommendation for lubricating the mo-
tor bearings. If the chiller is exposed to dusty and dirty
conditions during installation, lubricate the motor bear-
ings ahead of the suggested schedule.
DETERMINING CORRECT REFRIGERANT
CHARGE LEVEL
The refrigerant charge level is correct when the mea-
sured evaporator approach and discharge refrigerant
gas superheat are within the values listed in Table 8.
42
IMPORTANT
The chiller must be at design operating conditions
and full load operation before the correct refriger-
ant charge level can be properly determined.
TABLE 8 – REFRIGERANT CHARGE LEVEL
R-22
CONDITION
REFRIGERANT
COMFORT COOLING APPLICATIONS
EVAPORATOR
1-3°F
APPROACH
DISCHARGE
35-45°F
SUPERHEAT
BRINE (ICE MAKING) APPLICATIONS
EVAPORATOR
6-8°F
APPROACH
DISCHARGE
50-65°F
SUPERHEAT
Liquid refrigerant will be visible in the evaporator sight
glass. The refrigerant level cannot be properly deter-
mined by viewing the liquid refrigerant level in the evapo-
rator sight glass.
All YS Chillers shipped Form 1 are charged with the
correct amount of liquid refrigerant. Under some oper-
ating conditions the chiller may appear to be overcharged
with liquid refrigerant. Consult with the York Factory
prior to removing refrigerant. The liquid line isolation
valve may have to be partially throttled to prevent over-
feeding the evaporator in some applications and under
certain operating conditions.
Definitions:
Evaporator Approach = (S.E.T) - (L.E.L.T)
Discharge Superheat = (C.D.G.T) - (S.C.T)
Where:
S.E.T. = Saturated Evaporator Temperature
L.E.L.T. = Leaving Evaporator Liquid
Temperature
C.D.G.T. = Compressor Discharge Gas
Temperature
S.C.T. = Saturated Condensing Temperature
RERIGERANT CHARGING
Should it become necessary to add refrigerant charge
to a York YS Chiller; add charge until the evaporator
approach and refrigerant gas discharge superheat are
at within the values listed in Table 8.
R-134a
REFRIGERANT
1-3°F
12-18°F
6-8°F
24-36°F
YORK INTERNATIONAL