York YCAQ10, Руководство пользователя

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YORK INTERNATIONAL
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4. At the end of the 2 minute timer, the 10 minute anti-
recycle timer will start at T = 0. At this time the Micro
Board will check all system conditions. If no safeties
are tripped and cooling demand is present, the
compressor will start (unloaded). If a safety is tripped
or no cooling demand is present, the timer will stay
at T = 0 until proper conditions exist. Coincident with
the start of the compressor, the liquid line solenoid
will open after pumpdown is completed.
5. T = 4 sec. – The motor current of the compres-
sor must be > 30% FLA and < 115% FLA. Oil pres-
sure must be > 10 PSID. If these conditions are
not met, the compressor shuts down.
6. T = 30 sec. – At this time the oil pressure of the
compressor must be a minimum of 25 PSID and
suction pressure must be 80% of cutout.
7. T = 2 min. – Compressor will load if cooling de-
mand requires.
8. T = 4 min. – The compressor’s suction pressure
must be > cutout (cutout = 44 PSIG). At the same
time, the oil pressure of the compressor must be
> 20 PSID.
9. T = 10 min. – The anti-recycle timer times out.
This places the timer at T = 0 position. The com-
pressor will run as long as cooling demand exists.
10. If cooling demand drops and the compressor shuts
down, restart cannot occur until the 10 minute
anti-recycle timer times out and a minimum time
of 2 minutes passes. This assures a minimum time
of 2 minutes passes between starts, even if a
power failure occurs. At restart, the 10 minute
anti-recycle starts at T = 0.
11. Crankcase Heater – Any time the compressor
stops, the crankcase heater will be energized.
(YCHA100)
12. Pumpdown – The system is equipped with a
pumpdown on start-up routine which eliminates the
need for re-cycling pumpdown. On start-up of the
compressor, the system will pumpdown to approx.
15 lb. above the suction pressure cutout before the
liquid line solenoid opens. As a result of this, no
pumpdown mode is included in the system switch.
FAN CYCLING
Condenser Fans are normally cycled by the Micro in
response to outside ambient temperature. If the out-
side temp. is above 35°F, fans C and D will come on 4
sec. after the compressor starts. If the outside temp. is
above 55°F, fans A and B will come on 30 sec. after the
compressor starts.
Fan cycling by temperature can be overridden (at
temperatures below 55°F) by Condenser Pressure. If
the temp. requirements are not met to turn on the fans,
the fans will cycle according to discharge pressure on
the chart below.
LD01783
FAN FANS
DISCHARGE PRES.
CONTACTOR CONTROLLED
TO CYCLE FANS
“ON” “OFF”
5M C, D 260 LB. 190 LB.
6M A, B 280 LB. 210 LB.
CHILLER NO. OF CYLINDERS
MODEL 60 Hz 50 Hz
YCHA100 8 8
COMPRESSOR CAPACITY CONTROL
The function of the compressor capacity control sys-
tem is to automatically adjust the compressor pumping
capacity to balance with the cooling load at a predeter-
mined return water temperature and to permit the com-
pressor to start under partial load. The compressor ca-
pacity control system is actuated by means of high pres-
sure oil from the compressor oil pump. Oil pressure to
the power element loads the associated cylinders and
release of this pressure unloads them. Control of the
oil pressure to the unloader elements is the function of
the compressor capacity control solenoids located on
the front handhole cover. The compressor is loaded
when the solenoid is de-energized, and unloaded when
the solenoid is energized. Unloading is accomplished
by lifting and holding the suction valve off its seat. The
gas, drawn into the unloaded cylinders on the down
stroke of the piston, is pumped back into the suction
chamber of the compressor housing, without compres-
sion, when the piston returns on its up-stroke. All cylin-
ders equipped with unloaders will remain unloaded on
start-up until the oil pressure has built up to normal. On
the compressor, certain cylinders do not unload. (See
Fig. 10.)