Alarm Status Contacts; Remote Start/Stop Contacts; Remote Emergency Cutoff; Remote Temp Reset Input - York YCAL0019 Installation Operation & Maintenance

Alarm Status Contacts

Normally-open contacts are available for each re frigerant
system. These normally-open contacts close when the
system is functioning normally. The respective contacts
will open when the unit is shut down on a unit fault, or
locked out on a system fault. Field connections are at
TB1 terminals 29 to 30 (system 1), and terminals 31 to
32 (system 2 YCAL0043 - YCAL0066).

Remote Start/Stop Contacts

To remotely start and stop the chiller, dry contacts
can be wired in series with the fl ow switch and CTB1
- termi nals 13 to 14. Refer to FIG 4, 9 and unit wiring
diagram.

Remote Emergency Cutoff

Immediate shutdown of the chiller can be accomplished
by opening a fi eld-installed dry contact to break the elec-
trical circuit between terminals 5 to L on terminal block
TB1. The unit is shipped with a factory jumper installed
between terminals 5 to L, which must be removed if
emergency shutdown contacts are installed. Refer to
FIG. 9 and unit wiring diagram.

Remote Temp Reset Input

The Remote Temp Reset input allows reset of the chilled
liquid set point by supplying a voltage or current signal
fi eld wiring should be connected to CTB1 – terminals
A+ to A-. A detailed explanation is provided in the Unit
Control section. Refer to Fig's. 2 and 4 and unit wiring
diagram.
JOHNSON CONTROLS

Load Limit Input

Load limiting is a feature that prevents the unit from
loading beyond a desired value. The unit can be "load
limited" either 33%, 40%, 50%, 66% or 80%, depending
on the number of compressors on unit. The field
connections are wired to CTB1 – terminals 13 to 21, and
work in conjunction with the PWM inputs. A detailed
explanation is provided in the Unit Control section.
Refer to Fig. 4, 9 and unit wiring diagram.
When using the Load Limit feature,
the PWM feature will not function
– SIMULTANEOUS OPERATION
OF LOAD LIMITING AND TEM-
PERATURE RESET (PWM INPUT)
CANNOT BE DONE.

Flow Switch Input

The fl ow switch is fi eld wired to CTB1 terminals 13
- 14. See Page 22 and unit wiring diagram.

COMPRESSOR HEATERS

Compressor heaters are standard. ZP103, ZP120
& ZP137 compressors utilize 90W heaters; ZP180
compressors utilize 70W heaters; ZP235 compressors
utilize 120W heaters. If power is OFF more than two
hours, the crankcase heaters must be energized for 18 –
24 hours prior to restarting a compressor. This will assure
that liquid slugging and oil dilution does not damage the
compressors on start.

RELIEF VALVES

Relief valves are located on both the high and low
pressure side of the piping. High side relief valve
pressure setting is 650 PSIG. Low side relief valve
pressure setting is 450 PSIG.

HIGH PRESSURE CUTOUT

A high pressure cutout is installed in the discharge piping
of each system. The cutout opens at 585 PSIG ± 10
PSIG and closes at 440 PSIG ± 25 PSIG.
FORM 150.67-NM2 (209)
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