Volts Free Contacts; System Inputs - York eco2 YCAS0425EB Installation Operation & Maintenance

Installation
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
7.5 m (25 ft.) 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 close to start the chilled liquid
pump. This contact can be used as a master start/stop
for the pump in conjunction with the daily start/stop
schedule. If no schedule is set, and the customer has
master control of the pump, the contact must be used to
override the customer master start / stop so that the
YORK contact can start the pump in the event of a low
temperature liquid condition.
Run Contact
Terminals 29 and 30 close to indicate that a system is
running.
Alarm Contacts
Each system has a voltage-free change over contact
which will operate to signal an alarm condition when-
34
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 for No. 1 System and to
terminals 27 and 28 for No.2 System.

SYSTEM INPUTS

Flow Switch
A chilled liquid flow switch of suitable type must be
connected to terminals 13 and 14 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 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 Set Point Offset – Temperature
Timed closure of suitable contacts connected to termi-
nals 13 and 17 (PWM contacts) will give remote offset
function of the chilled liquid set point if required.
Remote Set Point Offset – Current
Timed contact closure of a suitable contact connected
to terminals 13 and 16 (PWM contacts) will give re-
mote offset of EMS% CURRENT LOAD LIMIT.
YORK INTERNATIONAL