Johnson Controls YCIV0157, Установка, эксплуатация и обслуживание

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JOHNSON CONTROLS
245
SECTION 8 - MICROPANEL
FORM 201.23-NM2
ISSUE DATE: 3/9/2015
8
fault with the associated fault information stored at the
instant the VSD fault occurred (i.e.: IGBT Gate Drive,
Single Phase Input, VSD CT Plug, etc.). The control
panel fault that occurred prior to the VSD fault will be
stored with the associated complete data related to the
fault as a numerically lower numbered history in the
history buffers.
High Discharge Pressure Cutout (Software)
Fault
The High Discharge Pressure Cutout is a software fault.
A system will fault and shut down with a controlled
ramped shutdown on high discharge pressure when the
discharge pressure rises above 274 PSIG for 0.5 sec-
onds. The system will be allowed to restart when the
discharge pressure falls to 259 PSIG. The system will
also be inhibited from starting if the pressure is above
259 PSIG. The fault message for this safety is shown
below:
SYS X YYYYYYYY HIGH DISCHARGE PRESSURE
X indicates the system and YYYYYYYY indicates
the system is in a “FAULT” condition and will restart
when the 120 second anti-recycle timer times out, or
“LOCKOUT” and will not restart until the operator
clears the fault using the keypad.
High Discharge Pressure Cutout (HPCO)
(Hardware) Fault
The mechanical High Pressure Cutout protects the
system from experiencing dangerously high discharge
pressure. A system will fault and shut down immedi-
ately when the mechanical high pressure cutout con-
tacts open. The fault will occur immediately and not
wait 3 seconds, which is typical of most system faults.
The HPCO is wired in series with the VSD Run Signal
and will only be checked by the Chiller Control Board
when the system is running. The mechanical cutout
opens at 315 plus or minus 8 PSIG and closes at 230
plus or minus 10 PSIG. The Status display fault mes-
sage for this system is shown below:
SYS X YYYYYYYY HPCO FAULT
X indicates the system and YYYYYYY indicates the
system is in a “FAULT” condition and will restart when
the 120 second anti-recycle timer times out or “LOCK-
OUT” and will not restart until the operator clears the
fault using the keypad.
Low Suction Pressure Cutout (Software) Fault
The programmable Low Suction Pressure Cutout is
a secondary back-up for the flow switch and protects
against operation with low refrigerant charge, which
helps protect the chiller from an evaporator freeze-up,
should the system attempt to run with a low refrigerant
charge. The Status display fault message for this cut-
out is shown below:
SYS X YYYYYYYY LOW SUCTION PRESSURE
X indicates the system and YYYYYYY indicates the
system is in a “FAULT” condition and will restart when
the 120 second anti-recycle timer times out or “LOCK-
OUT” and will not restart until the operator clears the
fault using the keypad. Typically, the cutout will be set
at 24 PSIG for chilled water applications.
The cutout is ignored for the first 30 seconds of system
run time. During the next 3 minutes of run time the
cutout point is linearly ramped from 10% of the cutout
value up to the programmed cutout point. If at any time
during the first 3 minutes of operation the suction pres-
sure falls below the ramped cutout point, the system
will shut down with a controlled ramped shutdown.
The cutout pressure during operating periods of 30 sec-
onds to 210 seconds is ramped and can be calculated
by:
Cutout = (Programmed Cutout x Run Time)–1.2 PSIG
200
After the first 3 minutes and 30 seconds of run time, if
the suction pressure falls below the cutout as a result
of a transient in the system, a transient timer is set at
30 seconds and a linearly ramped cutout is set start-
ing at 10% of the programmed cutout. If over the next
30 seconds, the suction pressure does not stay above
the ramped cutout, which ramps between 10% of the
cutout and the programmed cutout over the 30 second
period, the system will fault on low suction pressure.
Low Motor Current Cutout Fault
The Motor Current Cutout shuts the system down with
a controlled ramped shutdown when the microproces-
sor detects the absence of motor current (less than 10%
FLA), usually indicating that a compressor is not run-
ning. This safety is ignored for the first 10 seconds of
operation.