JOHNSON CONTROLS
76
FORM 145.05-NOM7
ISSUE DATE: 10/31/2019
SECTION 2 – INSTALLATION
PUMP START OUTPUT
The Unit Controller has a dry contact that can be used
to close a circuit to the condenser water pump. The
contact is located at terminal block TB-1 - terminal
11 and 12. The rating of the contact is 24 to 120VAC,
40MA to 1 AMP. This feature is provided as a conve-
nience. The condenser water pump does not have to be
connected and operated in this way.
The relay contact is closed whenever the UNIT MODE
is as follows:
• OCCUPIED STANDBY
• OCCUPIED COOLING
• UNOCCUPIED COOLING
ALARM CONTACTS
The Unit Controller has a set of dry Alarm Contacts
that are closed during a fault.
If
the unit experiences a
Fault, the Unit Controller closes a set of dry contacts
between terminals 7 and 8 of the low voltage terminal
block (CTB1).
Refer to SECTION 8 – SERVICE for a
listing of the unit faults that generate the alarm output.
ISOLATION DAMPER CONTROL
Some systems and building designs can require that the
unit be isolated from the supply and return duct sys-
tems. The unit controller can control this field design
and installation. On these systems, the Isolation Damp-
er must be opened before the Supply Fan Output can
be turned on, and it must be turned off once the Supply
Fan Output is turned off.
If the Isolation Damper Control is User Enabled, the
PUMP/AUX contacts are turned on when the preced-
ing conditions are met and remain in force for 120
seconds. The Supply Fan Output is energized after be-
ing delayed for 120 seconds to assure any dampers are
fully open; the PUMP/AUX contacts remains on for
120 seconds after the Supply Fan Output turns off, al-
lowing the static pressure to decrease.
The relay contact are closed whenever the Unit Mode
is OCCUPIED STANDBY, OCCUPIED COOLING,
or UNOCCUPIED COOLING.
PUMP START and ISOLATION DAMP-
ER use the same output but have different
operations. Therefore, only one of the
options can be used at a time.
CTB1 FIELD CONTROL WIRING (INPUTS)
24VAC switch voltage must be sourced
from the unit. Use of another power
source external of the unit may cause
equipment damage.