FORM NO.:6U6K-B01E-NB-EN
JOHNSON CONTROLS
36
WIRING
The units are shipped with all factory-mounted controls wired
for operation.
Field Wiring –
Power wiring must be provided through a
protector device (fused disconnect switch or circuit breaker)
to the input unit terminals in accordance with CE or local code
requirements. Maximum current is given in
Electrical Data
.
Copper power wiring only should be used for supplying
power to the unit. This is recommended to avoid safety and
reliability issues resulting from connection failure at the power
connections to the unit. Aluminum wiring is not recommended
due to thermal characteristics that may cause loose terminations
resulting from the contraction and expansion of the wiring.
Aluminum oxide may also build up at the termination causing
hot spots and eventual failure. If aluminum wiring is used to
supply power to the unit, AL-CU compression fittings should
be used to transition from aluminum to copper. This transition
should be done in an external box separate to the power panel.
Copper conductors can then be run from the box to the unit.
See unit wiring diagrams for field and power wiring
connections, communication wiring connections, modular
wiring, alarm contacts, inverter pump contacts, remote start/
stop input, remote cooling/ heating switch, etc. Refer to
SECTION 9 – UNIT OPERATION
for a detailed description of
operation concerning aforementioned contacts and inputs.
Pump Start Contacts
Terminal block XTB2 – terminals 21 to 22, are normally-
open contacts that can be used to switch field supplied power
to provide a start signal to the pump contactor. User-provided
pump contactor and thermal relay are required if the pump is
field installed. The contacts will be closed when any of the
following conditions occur:
1.Any compressor is running
2.The unit(s) is on and no flow fault occurred
3.Anti-freezing operation
4.Pump circulation mode
The pump will not run if the micro panel 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. Refer to unit
wiring diagram.
Alarm Status Contacts
Normally-open contacts are available for each unit. These
normally-open contacts remain open when the system is
functioning normally. The respective contacts will close when
the unit is shut down on a unit fault, or locked out on a system
fault. For modular applications, the master unit will not only
output internal fault, but also the fault of subordinate units.
Field connections are at XTB2 terminals 23 to 24.
Remote Start/ Stop Contacts
To remotely start and stop the unit, dry contacts can be wired to
XTB2 terminals 80G to 87. Refer to unit wiring diagram.
The function will be available after being activated through
HMI.
Remote Cooling/ Heating Switch
The contacts are used to switch unit operating mode remotely.
Dry contacts can be wired to XTB2 terminals 80F to 86. Refer
to unit wiring diagram.
The function will be available after being activated through
HMI.
Flow Switch Input
For modular combinations, it is recommended to install an
additional flow switch in outlet main pipe. The switch is to be
wired to terminals 80E – 85 of XTB2 located in the control
panel, as shown on the unit wiring diagram.
External Interlock
The unit will be allowed to run only if the interlock is
connected. It is used to link external facilities like fire alarms in
case there’s an emergency cutoff. It is wired to terminals 80H -
88 on block XTB2.
Make sure External Interlock is short-circuited or is linked to
external facilities before operation.
SECTION 4 – INSTALLATION
Cooke Industries - Phone: +64 9 579 2185 Email: [email protected] Web: www.cookeindustries.co.nz
