External Signal For Refrigeration Unit Failure; Auxiliary Safety Shutdown; Figure 19 - Remote Leaving Chilled Liquid Temp. Setpoint; Figure 20 - Auxiliary Safety Shutdown Input - York YZ Wiring Diagrams

FORM 161.01-PW2
ISSUE DATE: 7/18/2018
• If the Remote Setpoint Min is set to 36 and the
Max to 46, then the control signal will set the
setpoint for 1-11s 1s = 1°F above the min (If the
BAS wants a 42 degree setpoint they should send
a 7 seconds signal). Note that this reduced range
gives more resolution to the setpoint and is simi-
lar to the previous way that Temperature Setpoint
Reset was performed.
19 1
TB4
FIGURE 19 - REMOTE LEAVING CHILLED LIQUID
TEMP. SETPOINT
EXTERNAL SIGNAL FOR REFRIGERATION
UNIT FAILURE
When the Safety Shutdown Contacts (see Figure 3 on
page 8) are not connected to an Energy Manage-
ment System, they may be employed to energize a local
or remote safety alarm (by others). When the normally
open Safety Shutdown Contacts close, the alarm will
indicate shutdown of the unit. The cause of shutdown
will be one or more of the following safety controls:
• Low oil pressure
• High oil pressure
• High condenser pressure
• Low evaporator pressure
• High oil temperature
• High discharge temperature
• Auxiliary safety
JOHNSON CONTROLS
To Energy Management
System (Relay Closure)1 to 11
Second Pulse Width Modulated
(PWM) Signal with Contacts
Rated 5mA @ 115VAC
Field Wiring Term.
Board in OptiView
Control Center
LD23517
SECTION 1 - FIELD CONTROL MODIFICATIONS
• Power failure, when the Power Restart setpoint
on the control panel setup screen is set to manual
which implies that the chiller requires Manual
Restart After Failure.
If the unit was shut down because of
Cycling Shutdown Contacts (see Figure
2 on page 8) the alarm will not be en‑
ergized, but the unit will be shut down. A
closure of the safety alarm contacts means
that an operator must manually reset and
restart the unit.
When the Safety Shutdown contacts close, the Opti-
View™ Control Center will display the following mes-
sage: SAFETY SHUTDOWN – MANUAL RESTART,
and cause of shutdown.

AUXILIARY SAFETY SHUTDOWN

The closure of a Momentary, Maintained N.O. Switch
or Relay Contacts will cause the unit to shutdown and
display the following messages:
• SAFETY SHUTDOWN – MANUAL RESTART
• AUXILIARY SAFETY – CONTACTS CLOSED.
The unit will not restart until the contacts open, the
panel CLEAR FAULTS key is pressed and the unit is
given a start command.
Run
Stop
I/O
1
Board
(115 VAC)
TB2
Field Wiring Terminal Block in Graphic Control Center

FIGURE 20 - AUXILIARY SAFETY SHUTDOWN INPUT

Momentary or Maintained
N.O. Switch or Relay
Contacts Rated at
5mA @ 115 VAC
31
LD23518
15
1