FORM 150.60-NM4
YORK INTERNATIONAL
63
UNIT ON / OFF SWITCH
26572A(D)
UNIT ON/OFF SWITCH
A master UNIT ON/OFF switch is located on the key-
pad. This rocker switch allows the operator to turn the
entire chiller OFF if desired. The switch must be placed
in the ON position for the chiller to operate.
Whenever the switch is placed in the OFF position, a
STATUS display indicating the condition will be displayed.
This message is shown below.
SYSTEM SWITCHES
SYSTEM SWITCHES 1-4 are located on the microproc-
essor board (See Fig. 22). These allow the operator to
selectively turn a given system on or off as desired. On a
2 system chiller, switches 3 & 4 should be OFF. The
System Switch for a designated system must be ON
(Switch to right) for the system to operate.
Whenever a switch is placed in the OFF position, a STA-
TUS display indicating the condition will be displayed
indicating that the system does not have a Run Permis-
sive signal. A sample of this message is shown below.
NOTE: This message will not appear if Anti-recycle or
Anti-coincident timers are in effect and are be-
ing displayed.
ALARM CONTACTS (ANNUNCIATION ALARM)
Dry contacts connected to terminals 23 and 24 (Fig.
23) are supplied, which will transition to function as a
warning whenever a fault shutdown occurs on any sys-
tem or if power is lost to the control panel. The dry con-
tacts are normally open (N.O.) and will close when con-
trol power is applied to the panel, if no fault conditions
are present. If power is not lost or a fault lockout occurs,
the contact will open.
A 28VDC or 120VAC external alarm circuit (by others)
may be wired into the YORK supplied alarm contacts.
Any inductive load devices (relay, contactor), supplied by
the user which are connected to the dry contacts, MUST
be suppressed at the load. Use YORK P/N 031-00808-000
suppressor (not supplied). Failure to do this will result in
nuisance faults and possible damage to the chiller.
CAUTION: If the alarm circuit is applied in an applica-
tion used for critical duty (such as process
duty or cooling other critical equipment) and
the alarm circuit should fail to function,
YORK will not be liable for damages.
LEAD/LAG COMPRESSOR SELECTION
The chiller can be set up for AUTO or MANUAL Lead/Lag.
This is accomplished by configuring the S1 Dip Switches
properly on the microprocessor board. Details for doing
this are discussed in the OPTIONS key section.
When AUTO Lead/Lag is utilized, the micro determines
which compressor is assigned to the lead and the lag.
UNIT
ON/OFF SWITCH
U N I T
S W I T C H
I S
I N
T H E
O F F
P O S I T I O N
S Y S # 1
N O
R U N
P E R M
S Y S # 2
N O
R U N
P E R M
