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148
YORK INTERNATIONAL
FORM 201.18-NM1 (102)
LD03676
8.4
CONDENSER FAN CONTROL
The chiller is equipped with 8 or 10 condenser fans,
with 4 or 5 fans per system as given below. Fan control
is via Outside Ambient Temperature (OAT) and Dis-
charge Pressure (DP). There are six stages of fan con-
trol, utilizing 3 outputs per system. The fan stages will
work according to Table 2 or Table 3 depending on the
number of fans per system. There will be a minimum 5
second delay between all fan stages.
Condenser fan ON conditions are governed solely by the
Discharge Pressure (DP). When the DP rises above 220
PSIG, fan stage 1 is activated. From here, subsequent
fan stages are activated as the DP rises in increments of
15 PSIG, except stage 6, which is activated when the
DP rises over 290 PSIG. The system will remain at the
highest fan stage reached unless the OFF conditions are
satisfied.
Condenser fan OFF conditions are governed by both the
DP and OAT. Fan staging will be decreased from the high-
est fan stage reached if both the DP and OAT require-
ments are met. For example, if a system is at a fan stage
of 4, and the DP falls under 195 PSIG and the OAT drops
below 75°F, the fan stage will be reduced to 3.
The tables and descriptions that follow present fan
contactor data for the fans involved in each fan stage.
SYS 1 uses relay board #1. SYS 2 uses relay board #2.
YCAS0130, 0140, 0150, 0160, 0170 and 0180 models
have 4 condenser fans/system:
EPROM Versions C.ACS.09.01 (F350)
and C.ACS.09.02 (3902)
Fan operation on these versions is outlined in Tables 4
and 5. Condenser fan ON conditions are governed solely
by the Discharge Pressure (DP). When the DP rises
above 220 PSIG, fan stage 1 is activated. From there,
subsequent fan stages are activated as the discharge
pressure rises in increments of 15 PSIG, except stage
6, which is activated when the DP rises over 290 PSIG.
The system will remain at the highest fan stage reached
unless the OFF conditions outlined in the next paragraph
are satisfied.
Condenser fan OFF conditions are governed by both the
DP and OAT. Fan staging will be decreased from the high-
est fan stage reached if both the DP and OAT require-
ments are met. For example, if a system is at fan stage 4,
and the DP falls below 195 PSIG and the OAT drops be-
low 75°F, the fan stage will be reduced to stage 3.
EPROM Version C.A17.09.02 (5320)
Fan operation on these versions is outlined in Tables 6
and 7. These EPROM versions operate very similar to
versions 0 and 1. The only difference is that the ON/
OFF pressures are 15 PSIG lower. Condenser fan ON
conditions are governed solely by the Discharge Pres-
sure (DP). When the DP rises above 205 PSIG, fan
stage 1 is activated. From there, subsequent fan stages
are activated as the discharge pressure rises in incre-
ments of 15 PSIG, except stage 6, which is activated
when the DP rises over 275 PSIG. The system will
remain at the highest fan stage reached unless the OFF
conditions outlined in the next paragraph are satisfied.
Condenser fan OFF conditions are governed by both the
DP and OAT. Fan staging will be decreased from the high-
est fan stage reached if both the DP and OAT require-
ments are met. For example, if a system is at fan stage 4,
and the DP falls below 180 PSIG and the OAT drops be-
low 75°+ F, the fan stage will be reduced to stage 3.
EPROM Versions C.A32.09.02 (0483),
C.ACS.09.02 (D87E), and C.A06.09.03 (E10C)
These EPROMs operate according to the Flowchart in
Fig. 56. This control scheme is designed to minimize
fan cycling. Whenever discharge pressure stabilizes be-
tween 150 PSIG and 250 PSIG, the micro will neither
start or stop stages of fans.
If discharge pressure rises between 250 PSIG and 285
PSIG, the micro will add another fan stage and start a
15 minute timer. If the discharge pressure remains in
this range for 15 minutes, another step of fan cycling
will be added and the micro will restart the 15 minute
timer.
FIG. 52 –
CONDENSER FAN LAYOUT FOR DXST 2
COMPRESSOR UNITS
Micro Panel Contents
Содержание MILLENNIUM YCAS0230
Страница 45: ...45 YORK INTERNATIONAL FORM 201 18 NM1 102 This page intentionally left blank 7 ...
Страница 61: ...61 YORK INTERNATIONAL FORM 201 18 NM1 102 WIRING DIAGRAM WYE DELTA START FIG 21 CONT D LD03229 7 ...
Страница 67: ...67 YORK INTERNATIONAL FORM 201 18 NM1 102 LD03282 LD03283 LD03284 FIG 25 DETAIL A see pages 56 57 7 ...
Страница 69: ...69 YORK INTERNATIONAL FORM 201 18 NM1 102 COMPRESSOR TERMINAL BOX LD03233 FIG 29 COMPRESSOR TERMINAL BOXES 7 ...
Страница 70: ...70 YORK INTERNATIONAL FORM 201 18 NM1 102 Technical Data FIG 30 DETAIL B LD03285 ...
Страница 95: ...95 YORK INTERNATIONAL FORM 201 18 NM1 102 COMPRESSOR COMPONENTS CONT D FIG 43 COMPRESSOR COMPONENTS LD03670 7 ...
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