SECTION 4 - INSTALLATION
JOHNSON CONTROLS
47
FORM 201.28-NM1.1
ISSUE DATE: 1/31/2018
4
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. Cycle the pumps from the unit panel if
the unit will be operational or shut-down during sub-
freezing conditions. See "Evaporator Pump Control"
on page 102 for more information on testing the
pumps.
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 pro-
vide 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 115VAC circuit.
Contacts must be rated for low current (5mA). 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 115VAC circuit.
Contacts must be rated for low current (5mA). 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 Operat-
ing Data/Fault History to be made if an optional printer
is connected to the RS-232 port. The remote print cir-
cuitry is a 115VAC circuit. Contacts must be rated for
low current (5mA). 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
Limiting
A voltage signal connected to Terminals 40 and 41 of
1TB will provide remote setting of sound limit setpoint,
if required.
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