![background image](http://html1.mh-extra.com/html/york/ycul0045/ycul0045_installation-operation-and-maintenance_4223634085.webp)
JOHNSON CONTROLS
85
FORM 150.63-NM6 (1020)
UNIT SAFETIES:
Unit safeties are faults that cause all running compres-
sors to be shut down. Unit faults are auto reset faults
in that the unit will be allowed to restart automatically
after the fault condition is no longer present.
The Low Ambient Temp Cutout is a safety shutdown
designed to protect the chiller from operating in a low
ambient condition. If the outdoor ambient temperature
falls below the programmable cutout, the chiller will
shut down. Restart can occur when temperature rises
2°F above the cutoff.
The Under Voltage Safety assures that the system is not
operated at voltages where malfunction of the micropro-
cessor could result in system damage. When the 115VAC
to the micro panel drops below a certain level, a unit
fault is initiated to safely shut down the unit. Restart
is allowed after the unit is fully powered again and the
anti-recycle timers have finished counting down.
When the CURRENT FEEDBACK ONE PER UNIT
option is selected under the OPTIONS Key, the unit will
shut down when the voltage exceeds the programmed
trip voltage for 5 seconds.
The trip voltage is programmed at the factory according
to compressor or unit RLA.
Restart will occur after the anti-recycle timer times
out.
UNIT WARNING
The following messages are not unit safeties and will
not be logged to the history buffer. They are
unit warn-
ings
and will not auto-restart. Operator intervention is
required to allow a restart of the chiller.
The internal motor protector opens at 185°F - 248°F (85°C
- 120°C) and auto resets. The mechanical HP switch
opens at 405 PSIG +/- 10 PSIG (27.92 barg +/- .69 barg)
and closes at 330 PSIG +/- 25 PSIG (22.75 barg +/- 1.72
barg).
The compressor is also equipped with a discharge
temperature sensor for the purpose of sensing internal
scroll temperature. This sensor protects the scrolls from
overheating due to inadequate cooling that may occur
when the refrigerant charge is low, or superheat is too
high. When the sensor senses a high temperature, it
opens the motor protect circuit in the compressor caus-
ing the compressor to shut down.
During the first two faults an MP/HP INHIBIT message
will be displayed and the system will not be locked out.
Only after the 3rd fault will the MP/HP Fault message
shown below be displayed on the status display. Ad-
ditionally, the system will be locked out.
Whenever the motor protector or discharge sensor shuts
down a compressor and the system, the internal com-
pressor contacts will open for a period of 30 minutes to
assure that the motor or scroll temperatures have time
to dissipate the heat and cool down.
After 30 minutes, the contacts will close and the system
will be permitted to restart. The micro will not try to
restart the compressors in a system that shuts down on
this safety for a period of 30 minutes to allow the internal
compressor timer to time out.
When System Current Feedback option is selected (Op-
tion 11 under OPTIONS Key Current Feedback), this
safety will operate as follows. If the actual voltage of
the system exceeds the programmed trip voltage for 5
seconds, the system will shutdown. This fault will not
be cleared until the condition causing the high current
is no longer present.
2
S Y S 1 M P / H P C O F A U L T
S Y S 2 M P / H P C O F A U L T
U N I T F A U L T :
L O W A M B I E N T T E M P
U N I T F A U L T :
H I G H M T R C U R R
U
N I T F A U L T :
1 1 5 V A C U N D E R V O L T A G E
S Y S 1 H I G H M T R C U R R
S Y S 2 H I G H M T R C U R R
Summary of Contents for YCUL0045
Page 13: ...JOHNSON CONTROLS 13 FORM 150 63 NM6 1020 This page intentionally left blank...
Page 31: ...JOHNSON CONTROLS 31 FORM 150 63 NM6 1020 1 This page intentionally left blank...
Page 35: ...JOHNSON CONTROLS 35 FORM 150 63 NM6 1020 1 This page intentionally left blank...
Page 71: ...JOHNSON CONTROLS 71 FORM 150 63 NM6 1020 1 This page intentionally left blank...
Page 79: ...JOHNSON CONTROLS 79 FORM 150 63 NM6 1020 This page intentionally left blank...
Page 117: ...JOHNSON CONTROLS 117 FORM 150 63 NM6 1020 2 This page intentionally left blank...
Page 120: ...JOHNSON CONTROLS 120 FORM 150 63 NM6 1020 Unit Controls THIS PAGE INTENTIONALLY BLANK...
Page 139: ...JOHNSON CONTROLS 139 FORM 150 63 NM6 1020 3 This page intentionally left blank...
Page 141: ...JOHNSON CONTROLS 141 FORM 150 63 NM6 1020 4 LD08801...
Page 145: ...JOHNSON CONTROLS 145 FORM 150 63 NM6 1020 4 LD08946...
Page 147: ...JOHNSON CONTROLS 147 FORM 150 63 NM6 1020 4 LD08800...
Page 151: ...JOHNSON CONTROLS 151 FORM 150 63 NM6 1020 4 LD08776...
Page 153: ...JOHNSON CONTROLS 153 FORM 150 63 NM6 1020 4 LD08804...
Page 155: ...JOHNSON CONTROLS 155 FORM 150 63 NM6 1020 4 LD08781...
Page 157: ...JOHNSON CONTROLS 157 FORM 150 63 NM6 1020 4 This page intentionally left blank...
Page 159: ...JOHNSON CONTROLS 159 FORM 150 63 NM6 1020 4 LD08803...
Page 161: ...JOHNSON CONTROLS 161 FORM 150 63 NM6 1020 4 LD08807...
Page 163: ...JOHNSON CONTROLS 163 FORM 150 63 NM6 1020 4 LD08785...
Page 165: ...JOHNSON CONTROLS 165 FORM 150 63 NM6 1020 4 This page intentionally left blank...
Page 167: ...JOHNSON CONTROLS 167 FORM 150 63 NM6 1020 4 LD08806...