York YCAS Series, Installation Operation & Maintenance

Page: 189 / 216

189 YORK INTERNATIONAL
FORM 201.19-NM8 (804)
8
8.8 3 COMPRESSOR CONDENSER FAN
CONTROL
The chiller is equipped with 12 or 14 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 utiliz-
ing 3 outputs per system. The fan stages will operate
according to Table 5 or Table 6 depending on the number
of fans/system. There will be a minimum 5 sec ond 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, sub se quent
fan stages are activated as the DP rises in in cre ments of
15 PSIG, except stage 6, which is activated when the
DP rises over 290 PSIG. The system will re main at the
highest fan stage reached unless the OFF conditions
given in the next paragraph are satisfi ed.
Condenser fan OFF conditions are governed by both
the DP and OAT. Fan staging will be decreased from
the highest stage reached if both the DP and OAT re-
quire 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 ON/OFF conditions are provided in the next
two tables.
The tables below also indicate fan contactors, wire num-
bers, and Relay Output Board or I/O Expansion Board
Output numbers relating to fans energized. SYS 1 fan
contactors are controlled by Relay Output Board # 1.
SYS 2 by Relay Output Board # 2. SYS 3 is controlled
by I/O Expansion Board #2.
TABLE 5 –
CONDENSER FAN CONTROL AND FAN CONTACTOR DATA FOR DXST UNITS
WITH 4 FANS/SYSTEM
FIG. 79 –
CONDENSER FAN CONTROL LAYOUT FOR DXST COMPRESSORS UNITS
* At ambients above 85ºF, stages 3, 4, 5, and 6 will all turn on at 240 psig.
Fan
ON * OFF
Fan Wire
Relay
Stage
Fans Conditions Conditions
Contactor Number
Board
DP DP & OAT Output
1 1 >230 PSIG <160 PSIG & <60°F 9M 130 15
S
2 3 >240 PSIG <180 PSIG & <65°F 10M 131 14
Y
3 5, 7 >265 PSIG <195 PSIG & <70°F 11M, 12M 132 10
S
4 1, 5, 7 >275 PSIG <205 PSIG & <75°F 9M, 11M, 12M 130, 132 10,15
5 3, 5, 7 >285 PSIG <210 PSIG & <80°F 10M, 11M, 12M 131, 132 10, 14
1
6 1, 3, 5, 7 >295 PSIG <215 PSIG & <85°F 9M, 10M, 11M, 12M 130, 131, 132 10, 14, 15
1 2 >230 PSIG <160 PSIG & <60°F 15M 230 15
S
2 4 >240 PSIG <180 PSIG & <65°F 16M 231 14
Y
3 6, 8 >265 PSIG <195 PSIG & <70°F 17M, 18M 232 10
S
4 2, 6, 8 >275 PSIG <205 PSIG & <75°F 15M, 17M, 18M 230, 232 10, 15
5 4, 6, 8 >285 PSIG <210 PSIG & <80°F 16M, 17M, 18M 231, 232 10, 14
2
6 2, 4, 6, 8 >295 PSIG <215 PSIG & <85°F 15M, 16M, 17M, 18M 230, 231, 232 10, 14, 15
Fan
ON * OFF *
Fan Wire
I/O Expansion
Stage
Fans Conditions Conditions
Contactor Number
Board
DP DP & OAT Output TB3
1 13 >230 PSIG <160 PSIG & <60°F 21M 330 8
S
2 15 >240 PSIG <180 PSIG & <65°F 22M 331 9
Y
3 17, 19 >265 PSIG <195 PSIG & <70°F 23M, 24M 332 10
S
4 13, 17, 19 >275 PSIG <205 PSIG & <75°F 21M, 23M, 24M 330, 332 8, 10
5 15, 17, 19 >285 PSIG <210 PSIG & <80°F 22M, 23M, 24M 331, 332 9, 10
3
6 13, 15, 17, 19 >295 PSIG <215 PSIG & <85°F 21M, 22M, 23M, 24M 330, 331, 332 8, 9, 10
LD05022
$ (Not present on 60 Hz Models.)