
FORM 201.10-NM4
123
YORK INTERNATIONAL
MASTER (SYS 1 & 2)
CONTR
OL P
ANEL
SUBORDINATE
(SYS 3 & 4)
CONTROL P
ANEL
FAN
6
FAN
8
FAN
7
FAN
5
FAN
10
FAN
12
FAN
9
FAN
11
FAN
14
FAN
16
FAN
13
FAN
15
FAN
2
FAN
4
FAN
1
FAN
3
YDAS 410 - 490 FAN CONTROL STRATEGY
The chiller is equipped with 16 condenser fans; 4 per
system. Fan control from discharge pressure is stan-
dard. Fan start/stop pressures are programmable in the
PROGRAM Mode (Section 8) under FAN CONTROL
DISCHARGE PRESSURE SETPOINT and FAN ON/
OFF PRESS DIFF displays. Ambient temperature has
no effect on fan cycling.
When discharge pressure reaches the programmed
setpoint, the first pair of fans on a respective system
starts. After the first pair of fans are brought on in the
reverse direction, discharge pressure must rise an ad-
ditional 20 PSIG above the setpoint before a second
pair of fans will be brought on in the forward direction.
When this pair of fans starts, the reversing fans will
turn off. If discharge pressure rises 40 PSIG above the
FIG. 43
YDAS 410-490 FAN LOCATION/OPERATION
PRESSURE
FAN
FAN RELAY
ON
OFF
1 & 2 REV
9M & 10M
SETPOINT
SETPOINT - DIFF.
(SYS 1)
OR
5 & 6 REV
15M & 16M
SETPOINT
SETPOINT - DIFF.
(SYS 2)
3 & 4 FOR
6M & 8M
SETPOINT (SE 20 PSIG)
(SYS 1)
+ 20 PSIG
- DIFF.
OR
7 & 8 FOR
12M & 14M
SETPOINT (SE 20 PSIG)
(SYS 2)
+ 20 PSIG
- DIFF.
1 & 2 FOR
5M & 7M
SETPOINT (SE 40 PSIG)
(SYS 1)
+ 40 PSIG
- DIFF.
OR
5 & 6 FOR
11M & 13M
SETPOINT (SE 40 PSIG)
(SYS 2)
+ 40 PSIG
- DIFF.
LD03803
PRESSURE
FAN
FAN RELAY
ON
OFF
9 & 10 REV
9M & 10M
SETPOINT
SETPOINT - DIFF.
(SYS 3)
OR
13 & 14 REV
15M & 16M
SETPOINT
SETPOINT - DIFF.
(SYS 4)
11 & 12 FOR
6M & 8M
SETPOINT (SE 20 PSIG)
(SYS 3)
+ 20 PSIG
- DIFF.
OR
15 & 16 FOR
12M & 14M
SETPOINT (SE 20 PSIG)
(SYS 4)
+ 20 PSIG
- DIFF.
9 & 10 FOR
5M & 7M
SETPOINT (SE 40 PSIG)
(SYS 3)
+ 40 PSIG
- DIFF.
OR
13 & 14 FOR
11M & 13M
SETPOINT (SE 40 PSIG)
(SYS 4)
+ 40 PSIG
- DIFF.
setpoint, a second pair of fans will start in the forward
direction. This is the same pair of fans that originally
ran in the reverse direction. The first pair of forward
fans will also continue to run.
The point at which each pair of fans cycles off is also
programmable. This is accomplished in the PROGRAM
Mode when the FAN ON/OFF PRESS DIFF display
appears. The progammable differential establishes the
pressure at which each pair of fans turn off. The differ-
ential is the amount the discharge pressure must drop
below the pressure at which the fan turned on.
Locations of the fans and a table showing the operation
is shown in Fig. 43.
Содержание Millennium YDAS 410
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