Table of Contents
Advertisement
1.14 CONTROL PANEL
No controls (Relays etc.) should be mounted in any
section of the control panels. Additionally control wir-
ing not connected to the YORK Control Panel should
not be run through the Control Panel. If these precau-
tions are not followed, electrical noise could cause mal-
functions or damage to the unit and its controls.
1.15 REMOTE EMERGENCY STOP DEVICE
A remote emergency stop device can be connected to
terminals 3 and 4 in the common input supply section
after removing a link. When operated it removes the
115VAC control supply and supply to the electronics.
All devices are de-energized including compressor con-
tractors. The loss of supply to the power supply board
results in the display going off.
To conform with the requirement of
EN 418 and EN 60204-1 that re-set-
ting the emergency stop device will not
initiate a restart, 'POWER FAIL RE-
START' should be programmed under
the 'PROGRAM' key to 'MANUAL'.
'MANUAL' restart requires a reset us-
ing the unit ON/OFF switch under the
keypad.
1.16 COMMON INPUT POWER SECTION VOLTAGE
FREE CONTACTS
All wiring to the power section voltage free contacts
requires a supply provided by the customer maximum
voltage 254 volts AC, 28VDC. These contacts are on
the customer relay board -ACRB in the common input
power section, the terminals being on a removable plug
for ease of wiring.
The terminal numbers are situated on
the circuit board, not the plug. The
customer must take particular care
deriving the supplies for the voltage
free terminals with regard to a com-
mon point of isolation. Thus, these cir-
cuits when used must be fed via the
common point of isolation so the volt-
age to these circuits is removed when
the common point of isolation to the
unit is opened. This common point of
isolation is not supplied by YORK.
YORK INTERNATIONAL
In accordance with the National Electrical Code
(N.E.C.) it is recommended that the customer wiring to
these terminals uses orange wires. This will ensure that
circuits not switched off by the units supply disconnect-
ing device are distinguished by color, so that they can
easily be identified as live even when the unit discon-
necting devices are off. The YORK voltage free con-
tacts are rated at 125VA. All inductive devices (relays)
switched by the YORK voltage free contacts must have
their coil suppressed using standard R/C suppressors.
If these precautions are not followed, electrical noise
could cause malfunctions or damage to the unit and its
controls.
1.17 ALARM CONTACTS
Each system has a voltage free contact which will
OPEN to signal an alarm condition whenever a system
locks out or there is a power failure. To obtain a sys-
tem alarm signal, connect live to Terminal 1 and use
terminal 8 for No. 1 system alarm and terminal 7 for
No. 2 system alarm.
1.18 CHILLED LIQUID PUMP CONTACT
YORK provides a voltage free contact terminals 5 and 6
which close to start a 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 the con-
tact will close when the unit switch is set to on. The
contact must be used so that the contact can start the
pump in the event of a low temperate liquid condition.
A stop start timer is included so that the pump will not
be asked to restart within 30 seconds of stopping.
1.19 RUN CONTACT
YORK provides a run contact which closes terminals
3 and 4 to indicate that the unit is running. This contact
closes when any system runs. This contact can be used
to start the condenser pump or fan.
1.20 ANTI-RECYCLE TIMER
The programmable anti-recycle timer allows the user to
select the compressor anti-recycle time to best suit their
needs. Motor heating occurs as a result of inrush current
when the motor is started. This heat must be dissipated
before another start takes place or motor damage may
result. The anti-recycle timer assures that the motor has
sufficient time to cool before it is restarted.
FORM 201.25-NM1 (302)
7
37
Advertisement
Table of Contents
