JOHNSON CONTROLS
12
FORM 150.68-EG1 (0212)
ELECTRICAL CONNECTION
The following connection recommendations are intended
to ensure safe and satisfactory operation of the unit.
Failure to follow these recommendations could cause
harm to persons, or damage to the unit, and may invalidate
the warranty.
No additional controls (relays, etc.) should be mounted in
the control panel. Power and control wiring not connected
to the control panel should not be run through the control
panel. If these precautions are not followed it could lead
to a risk of electrocution. In addition, electrical noise could
cause malfunctions or damage the unit and its controls.
POWER WIRING
These units are suitable for 460 V, 3-phase, 60Hz nominal
supplies only.
All electrical wiring should be carried out in accordance
with local regulations. Route properly sized cables to the
cable entries in the bottom of the power panel.
It is the responsibility of the user to install over current
protection devices between the supply conductors and
the power supply terminals on the unit.
To ensure that no eddy currents are set up in the power
panel, the cables forming each 3 phase power supply
must enter via the same cable entry.
All sources of supply to the unit must be taken via a
common point of isolation (not supplied by JCI).
SINGLE POINT POWER SUPPLY WIRING
All models require one fi eld provided 460 V, 3Ø, 60 Hz
+ PE (Protected Earth) supply to the unit with circuit
protection.
Connect the 3-phase supply to the non-fused disconnect
switch located in the power panel using M12 lugs.
Connect the earth wire to the main protective earth
terminal located in the power panel using a M10 lug.
CONTROL CIRCUIT TRANSFORMER
The control circuit transformer providing the 115 V,
1Ø, 50Hz supply to the unit control system is fi tted in a
separate enclosure.
REMOTE EMERGENCY STOP DEVICE
If required, a remote emergency stop device may be wired
into the unit. This device should be rated at 20 amps, 115V,
AC-15. The device should be wired into terminals L and
5 in the power panel after removing the factory fi tted link.
CONTROL WIRING - VOLTAGE FREE CONTACT
All wiring to the voltage free contact terminal block requires
a supply provided by the customer maximum voltage
115Vac, 24 Vdc.
The customer must take particular care deriving the
supplies for the voltage free terminals with regard to a
common point of isolation. Thus, these circuits when
used must be fed via the common point of isolation so the
voltage 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 JCI.
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 disconnecting device
are distinguished by colour, so that they can easily be
identifi ed as live even when the unit disconnecting devices
are off. The YORK voltage free contacts are rated at 125
VA.
All inductive devices (relays) switched by the YORK
voltage free contacts must have their coil suppressed
using standard RC suppressors. If these precautions are
not followed, electrical noise could cause malfunctions or
damage to the unit and its controls.
Chilled Liquid Pump Starter
Terminals 23 and 24 close to start the liquid pump. This
contact is closed if there is a ‘Leaving Liquid Temperature
Cutout’ or any of the compressors are running or the
daily schedule is not calling for a shutdown with the unit
switch on.
The contact must be used to ensure that the pump is
running in the event of a ‘Leaving Liquid Temperature
Cutout’.
The pump contact will not close to run the pump if the unit
has been powered up for less than 30 seconds, or if the
pump has run in the last 30 seconds, to prevent pump
motor overheating.
Run Contacts
Terminals 25 and 26 close to indicate that refrigerant
system 1 is running and terminals 27 and 28 close to
indicate that refrigerant system 2 is running.
Application Data - continued
