Specifications

61
JOHNSON CONTROLS
Form 201.28-NM1.EN.PED/CE (0211)
7
Sensor Failure Cutout Fault
The Sensor Failure Cutout prevents the system from
running when a critical sensor (transducer, level sensor,
or motor winding temp sensor) is not functioning
properly and reading out of range. This safety is checked
at startup and will prevent the system from running if
one of the sensors has failed.
The sensor failure safety will also fault and shutdown
a system while in operation, if a safety threshold is
exceeded or a sensor reads out of range (high or low).
Following is the Status display fault message.
SYS X FAULT: SENSOR FAIL: YYYYYYYYYYYY
The X indicates the specifi c system. FAULT
will either indicate the system is in a
“FAULT” condition and will restart when
the fault clears, or “LOCKOUT” after 3
faults and will not restart until the operator
clears the fault using the keypad.
YYYYYYYYYYYY indicates the failed sensor below:
• SUCT PRESS
• OIL PRESS
• DISCH PRESS
• MOTOR TEMP
The start inhibit thresholds for each sensor are shown in
the following table.
TABLE 5 - START INHIBIT SENSOR THRESHOLDS
SENSOR
LOW
THRESHOLD
HIGH
THRESHOLD
SUCTION
TRANSDUCER
0.3 Vdc 4.7 Vdc
OIL
TRANSDUCER
0.3 Vdc 4.7 Vdc
DISCHARGE
TRANSDUCER
0.3 Vdc 4.7 Vdc
MOTOR TEMP.
SENSOR
0°C (0ºF) 116°C (240ºF)
High Motor Temperature Cutout Fault
The High Motor Temperature Cutout prevents a
compressor from running when its motor temperature is
too high. A system will fault and shut down when any
compressor motor temperature sensor rises above 121°C
(250°F). The system will be inhibited from starting if its
motor temperatures sensors indicate temperatures above
116°C (240°F). If any single temperature sensor is being
ignored under the Unit Set-up Mode, that sensor will not
be utilized when evaluating motor temperature.
Below is a sample Status display fault message:
SYS X FAULT: HIGH MOTOR TEMP
The X indicates the system and FAULT indicates the
system is in a “FAULT” condition and will restart when
the fault clears or “LOCKOUT” and will not restart until
the operator clears the fault using the keypad.
System Control Voltage Cutout Fault
The System Control Voltage Cutout alerts the operator
the 115VAC Control voltage to one of the systems is
missing. This could be due to a system fuse that has been
removed or is blown. The affected system will fault and
shut down immediately when the 115VAC supply is lost.
The safety will “not” shut down a system if the UNIT
switch is OFF, which electrically removes the 115VAC
to “all” systems. The safety is only used to indicate a
situation where a single system is missing the 115VAC.
The safety will not cause a lockout and the system fault
will reset when power is returned. A sample message is
shown below:
SYS X FAULT: CONTROL VOLTAGE
The X indicates the system and FAULT indicates the
system is in a “FAULT” condition and will restart when
the fault clears or “LOCKOUT” and will not restart until
the operator clears the fault using the keypad.