Compressor Condenser Fan Control; Table 5 - Condenser Fan Control And Fan Contactor Data For Dxst Units; Table 8 - Condenser Fan Control And Fan Contactor Data For Dxst Units; Fig. 79 - Condenser Fan Control Layout For Dxst Compressors Units - York YCAS Series Installation Operation & Maintenance

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
FIG. 79 – CONDENSER FAN CONTROL LAYOUT FOR DXST COMPRESSORS UNITS
TABLE 5 – CONDENSER FAN CONTROL AND FAN CONTACTOR DATA FOR DXST UNITS
WITH 4 FANS/SYSTEM
Fan
Fans
Stage
1 1
S
2 3
Y
3 5, 7
S
4 1, 5, 7
5 3, 5, 7
1
6 1, 3, 5, 7
1 2
S
2 4
Y
3 6, 8
S
4 2, 6, 8
5 4, 6, 8
2
6 2, 4, 6, 8
Fan
Fans
Stage
1 13
S
2 15
Y
3 17, 19
S
4 13, 17, 19
5 15, 17, 19
3
6 13, 15, 17, 19
* At ambients above 85ºF, stages 3, 4, 5, and 6 will all turn on at 240 psig.
YORK INTERNATIONAL
$ (Not present on 60 Hz Models.)
ON * OFF
Conditions Conditions
DP DP & OAT
>230 PSIG <160 PSIG & <60°F
>240 PSIG <180 PSIG & <65°F
>265 PSIG <195 PSIG & <70°F
>275 PSIG <205 PSIG & <75°F
>285 PSIG <210 PSIG & <80°F
>295 PSIG <215 PSIG & <85°F
>230 PSIG <160 PSIG & <60°F
>240 PSIG <180 PSIG & <65°F
>265 PSIG <195 PSIG & <70°F
>275 PSIG <205 PSIG & <75°F
>285 PSIG <210 PSIG & <80°F
>295 PSIG <215 PSIG & <85°F
ON * OFF *
Conditions Conditions
DP DP & OAT
>230 PSIG <160 PSIG & <60°F
>240 PSIG <180 PSIG & <65°F
>265 PSIG <195 PSIG & <70°F
>275 PSIG <205 PSIG & <75°F
>285 PSIG <210 PSIG & <80°F
>295 PSIG <215 PSIG & <85°F
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.
Fan
Contactor
9M
10M
11M, 12M
9M, 11M, 12M
10M, 11M, 12M
9M, 10M, 11M, 12M
15M
16M
17M, 18M
15M, 17M, 18M
16M, 17M, 18M
15M, 16M, 17M, 18M
Fan
Contactor
21M
22M
23M, 24M
21M, 23M, 24M
22M, 23M, 24M
21M, 22M, 23M, 24M
FORM 201.19-NM8 (804)
LD05022
Relay
Wire
Board
Number
Output
130 15
131 14
132 10
130, 132 10,15
131, 132 10, 14
130, 131, 132 10, 14, 15
230 15
231 14
232 10
230, 232 10, 15
231, 232 10, 14
230, 231, 232 10, 14, 15
I/O Expansion
Wire
Board
Number
Output TB3
330 8
331 9
332 10
330, 332 8, 10
331, 332 9, 10
330, 331, 332 8, 9, 10
189
8