York Millennium YK M3 M3 G4 THRU YK S6 S4 J2 - Manual (Page 33)

YORK INTERNATIONAL 33
FORM 160.49-O2
be no lower than the value determined by referring to
the formula below:
100
Min. ECWT = LCHWT—C RANGE + 5 +
( 15 x % LOAD )
where:
ECWT = entering condensing water temperature
LCHWT = leaving chilled water temperature
C RANGE = condensing water temperature range
At start-up, the entering condenser water temperature
may be as much as 25°F colder than the standby re-
turn chilled water temperature. Cooling tower fan
cycling will normally provide adequate control of the
entering condenser water temperature on most instal-
lations.
CHECKING OPERATION
During operation, the following conditions should be
periodically checked:
1. On starting, the prerotation vanes should remain
closed until the compressor motor is up to speed
on the run winding; then the vane motor should cause
the vanes to modulate with load requirements.
2. Be sure the oil pump is operating while unit is run-
ning.
3. Check Oil Pressure display. A gradual decrease in
bearing oil pressure of 5 to 10 psi (with constant
suction and discharge pressures) may be an indi-
cation of a dirty filter. The filter should be replaced
when pressure loss is 30% or more of the original
pressure. The actual bearing oil pressure will vary
with compressor suction and discharge pressures.
When a new system is first operated under normal
full load conditions, the bearing oil pressure should
be recorded as a reference point with which to com-
pare subsequent readings.
OPERATING LOG SHEET
A permanent daily record of system operating condi-
tions (temperatures and pressures) recorded at regu-
lar intervals throughout each 24 hour operating period
should be kept.
An optional status printer is available for this purpose
or Fig. 16 shows a log sheet used by YORK Personnel
for recording test data on chiller systems. It is avail-
able from the factory in pads of 50 sheets each under
Form 160.44-F6 and may be obtained through the nearest
FIG. 16 – LIQUID CHILLER LOG SHEETS
*NOTE: These items can be printed by an electronic printer connected to TB8 of the Micro Board and pressing the PRINT key on the
Micro Board or automatically using the Data Logger feature.
LD00467
23889A