JOHNSON CONTROLS
10
FORM 161.01-PW2
ISSUE DATE: 7/18/2018
SECTION 1 - FIELD CONTROL MODIFICATIONS
AUXILIARY SAFETY SHUTDOWN
When 115 VAC is switched to TB2-31 from a chiller
source at TB2-1, a safety shutdown of the chiller is
commanded. The contacts must open and a manual re-
set is performed at the panel to restart.
FIGURE 7 - AUXILIARY SAFETY SHUTDOWN
LD23510
I/O
Board
TB2
131
REMOTE/LOCAL CYCLING DEVICES
The closure of an automatically reset device across this
input will permit the unit to operate in all operating
modes. Conversely, opening device contacts will in-
hibit the unit from operating. The OptiView™ Control
Center will then display the following messages.
• CYCLING SHUTDOWN – AUTO RESTART
• SYSTEM CYCLING – CONTACTS OPEN.
The OptiView Control Center allows au‑
tomatic start and stop conguration of
the unit on a daily basis, at pre-dened
time intervals. In the control center clock,
select daily schedule of Start and Stop
time (Sunday through Saturday including
holidays in a week) as a standard feature,
up to one week at a time. An additional
program timer is not required for this.
FIGURE 8 - REMOTE/LOCAL CYCLING DEVICES
LD23511
Field wiring terminal
block in OptiView
control center
I/O
Board
TB2
1 13
Remove
jumper wire
Thermostat cycling
switch program timer
contact remote start-stop
switch (maintained)
contacts rated
5mA @ 115VAC
MULTI-UNIT CYCLING SHUTDOWN
For multiple chiller installation applications, Multi-Unit
Cycling Shutdown contacts are available to start and
stop each unit. The maintained closure of device con-
tacts across TB2-1 and TB2-9 will permit the unit to
operate in all the operating modes with a standing Run
command. Conversely, opening device contacts will
inhibit the unit from operating. The OptiView™ Con-
trol Center will then display the following messages:
• CYCLING SHUTDOWN – AUTO RESTART
• MULTIUNIT CYCLING – CONTACTS OPEN
FIGURE 9 - MULTI-UNIT CYCLING SHUTDOWN
LD23512
Remove
jumper
wire
Multi-unit switch with
contacts rated
5mA @ 115 VAC
I/O
Board
TB2
91
Field wiring terminal block
in OptiView control center
CHILLED LIQUID PUMP RUN (TB4-44/45)
When the chiller is started, the contacts close imme-
diately upon entering “MBC Startup”. Normally, they
open in coincidence with the receipt of a STOP com-
mand or a fault other than those listed below.
A. LEAVING CHILLED LIQUID - LOW TEM-
PERATURE cycling shutdown.
B. If Chilled Liquid Pump Operation is set to
ENHANCED, MULTIUNIT CYCLING -
CONTACTS OPEN or SYSTEM CYCLING -
CONTACTS OPEN cycling shutdown.
C. LEAVING CHILLED LIQUID FLOW SWITCH
OPEN cycling shutdown.
FIGURE 10 - CHILLED LIQUID PUMP RUN
LD23513
TB4
DO
44
45
I/O
Board
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