FORM 150.44-NM4
29
YORK INTERNATIONAL
SWITCH 7
OPEN:
SYS 1 can be selected as the lag compressor by clos-
ing a user supplied contact between Terminal 13 and
19. See page 61.
CLOSED:
In this mode the micro determines which compressor
is assigned to the lead and the lag. A new lead/lag
assignment is made whenever both compressors shut
down. The micro will then assign the lead to the com-
pressor with the shortest anti-recycle time.
SWITCH 8
OPEN:
Fan control will be by outside ambient temp. This will
be the standard mode of fan control for normal opera-
tion. In this mode, maximum chiller efficiency will be
achieved. If the Low Ambient option is installed, the
fan control will automatically change to pressure con-
trol at temperatures below 25°F. See page 66 for fan
control sequence.
CLOSED:
Fan control is by discharge pressure only. This mode
of fan control will increase discharge pressure. It should
be used if nuisance low suction pressure faults are ex-
perienced. See page 77 for fan control sequence.
NOTE: Discharge pressure transducers
must
be in-
stalled. These are optional (Discharge Pres-
sure Read-out Option) unless a Low Ambient
Kit is installed.
M A N U A L
L E A D / L A G
A M B I E N T
&
D I S C H
P R
F A N
C O N T R O L
A U T O M A T I C
L E A D / L A G
D I S C H A R G E
P R E S S U R E
F A N
C O N T R O L