Remote Emergency Stop Device; Control Panel Wiring; Volts Free Contacts; Chilled Liquid Pump Starter - York YCAS Series Installation Operation & Maintenance

Installation
Removing high voltage power to the
chiller will remove the 115VAC sup-
ply voltage to the microprocessor cir-
cuitry and the evaporator heater. In
cold weather, this could cause serious
damage to the chiller due to evapora-
tor freeze-up. Do not remove power
unless alternate means are taken to
ensure operation of the evaporator
heater.

Remote Emergency Stop Device

If required, a remote emergency stop device can be
wired into the unit. The device should be wired into
terminals 31 and 32 (Figs. 12 and 13, pages 35 and 36)
in the microprocessor control panel.

CONTROL PANEL WIRING

All wiring to the control panel terminal block is nomi-
nal 30VDC and must be run in shielded cable, with the
shield grounded at the panel end only. Run shielded
cable separately from mains cable to avoid electrical
noise pick-up. Use the control panel cable entry to avoid
the power cables.
The voltage free contacts must be suitable for 30VDC
(gold contacts recommended). If the voltage free con-
tacts form part of a relay or contactor, the coil of the
device must be suppressed using a standard R/C sup-
pressor. The above precautions must be taken to avoid
electrical noise which could cause a malfunction or dam-
age to the unit and its controls.
The length of cable to these terminals must not exceed
25 ft. (7.5 m) unless an optional input isolator kit is
fitted. The optional input isolator kit uses 15VDC (not
30VDC).

VOLTS FREE CONTACTS

Chilled Liquid Pump Starter

Terminals 25 and 26 (Figs. 12 and 13, pages 35 and 36)
close to start the chilled liquid pump. This contact can
be used as a master start/stop for the pump in conjunc-
tion with the daily start/stop schedule.
30

Run Contact

Terminals 29 and 30 (Figs. 12 and 13, pages 35 and 36)
close to indicate that a system is running.

Alarm Contacts

Each system has a voltage-free changeover contact
which will operate to signal an alarm condition when-
ever a system locks out, or there is a power failure. To
obtain system alarm signal, connect the alarm circuit to
volt free terminals 23 and 24 (Figs. 12 and 13, pages 35
and 36) for No. 1 System and to terminals 27 and 28
(Figs. 12 and 13, pages 35 and 36) for No. 2 System.

SYSTEM INPUTS

Flow Switch

A chilled liquid flow switch of suitable type must be
connected to terminals 13 and 14 (Figs. 12 and 13, pages
35 and 36) to provide adequate protection against loss
of liquid flow.
Remote Run / Stop
Connect remote switch(es) in series with the flow switch
to provide remote run/stop control if required.

Remote Print

Closure of suitable contacts connected to terminals 13
and 18 (Figs. 12 and 13, pages 35 and 36) will cause a
hard copy printout of Operating Data/Fault History to
be made if an optional printer is connected to the RS
232 port.
Remote Setpoint Offset – Temperature
Timed closure of suitable contacts connected to ter-
minals 13 and 17 (PWM contacts) will provide re-
mote offset function of the chilled liquid setpoint if re-
quired (Figs. 12 and 13, pages 35 and 36) for contact
location.
Remote Setpoint Offset – Current
Timed contact closure of a suitable contact connected
to terminals 13 and 16 (PWM contacts) will provide
remote offset of EMS% CURRENT LOAD LIMIT. See
(Figs. 12 and 13, pages 35 and 36) for contact location.
FORM 201.18-NM1 (102)
YORK INTERNATIONAL