Specifications

29
JOHNSON CONTROLS
Form 201.28-NM1.EN.PED/CE (0211)
4
CONTROL WIRING
All control wiring utilizing contact closures to the control
panel terminal block is nominal 115VAC and must be run
in shielded cable, with the shield grounded at the panel
end only, and run in water tight conduit. Run shielded
cable separately from mains cable to avoid electrical
noise pick-up. Use the control panel cable entry to avoid
the power cables.
Voltage free contacts connected to the panel must be
suitable for 115 Vac 10 ma (gold contacts recommended).
If the voltage free contacts form part of a relay or contactor,
the coil of the device must be suppressed using a standard
R/C suppressor. The above precautions must be taken to
avoid electrical noise, which could cause a malfunction or
damage to the unit and its controls.
VOLTS FREE CONTACTS
Chilled Liquid Pump Starter
Terminals 23 and 24 on 1TB 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.
Run Contact
Terminals 21 and 22 on 1TB close to indicate that a
system is running.
Alarm Contacts
Each system has a single voltage-free contact, which
will operate to signal an alarm condition whenever any
system locks out, or there is a power failure. To obtain
system alarm signal, connect the alarm circuit to volt free
Terminals 25 & 26 (Sys 1), Terminals 27 and 28 (Sys 2)
of 1TB.
SYSTEM INPUTS
Flow Switch
A chilled liquid flow switch of suitable type MUST be
connected between Terminals 2 and 13 of 1TB to provide
protection against loss of liquid flow, which will cause
evaporator freeze-up if the chiller is permitted to run.
The flow switch circuitry is a 115 Vac circuit. Contacts
must be rated for low current (5 mA). Gold contacts
should be used.
Remote Run / Stop
A Remote Run/Stop input is available for each systems.
These inputs require a dry contact to start and stop the
system. System 1 remote dry contacts are connected
between Terminals 2 and 15 of 1TB and System 2 dry
contacts are connected between Terminals 2 and 16 of
1TB. If remote start/stop is not utilized, a jumper must
be paced across the terminals to allow the system to
run. The remote run/stop circuitry is a 115 Vac circuit.
Contacts must be rated for low current (5 mA). Gold
contacts should be used.
Remote Print
Closure of suitable contacts connected to Terminals
2 and 14 of 1TB 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. The remote print
circuitry is a 115 Vac circuit. Contacts must be rated for
low current (5 mA). Gold contacts should be used.
Optional Remote Setpoint Offset – Temperature
A voltage signal connected to Terminals 17 and 18 of
1TB will provide a remote offset function of the chilled
liquid setpoint, if required.
Optional Remote Setpoint Offset – Current
A voltage signal connected to Terminals 19 and 20
of 1TB will provide a remote setting of current limit
setpoint, if required.
Optional Remote Setpoint Offset – Sound Lim-
iting
A voltage signal connected to Terminals 40 and 41 of
1TB will provide remote setting of sound limit setpoint,
if required.