Johnson Controls YORK OPTIVIEW CONTROL CENTER, Operation Manual

Page: 112 / 142

JOHNSON CONTROLS
112
FORM 160.10-O1
ISSUE DATE: 4/27/2018
SECTION 3 - OPTIVIEW DISPLAY MESSAGES
The harmonic filter logic board generates a filter DC
link voltage by switching the filter IGBT’s. This DC
level is higher than the level that could obtained by
only rectifying the input line voltage. By generating
the DC link voltage, the harmonic filter performs a
voltage BOOST function. This is necessary in order to
permit current to flow into the power line from the fil-
ter when the input line is at peak level. This varies with
the input line-to-line voltage. If this shutdown occurs,
the likely cause is a severe sag in the input line voltage.
Harmonic Filter – Precharge – Low DC Bus
Voltage
During precharge, the filter’s DC link must be equal
to or greater than 50 VDC (41 VDC for 50 Hz) within
1/10 second after the precharge relay is energized. If
this condition is not met, a shutdown is performed and
this message is generated.
Harmonic Filter – DC Bus Voltage
Imbalance
This shutdown occurs when the shared voltage be-
tween the DC link capacitors is not within specifica-
tions. The electrolytic capacitors, rated for 450 VDC,
are wired in series to achieve a 900 VDC capability for
the DC link. The voltage must be shared equally from
the junction of the center or series capacitor connec-
tion, to the negative bus and to the positive bus. This
center point should be approximately half of the total
DC link voltage.
Harmonic Filter – Input Current Overload
The three phases of RMS filter current are monitored
and if any one of the three phases continuously exceeds
a given threshold for seven (7) seconds, a chiller shut-
down is performed and this message is displayed. The
maximum permissible continuous RMS current ratings
for the harmonic filter are as follows:
• 351/292 HP: 128 AMPS
• 503/419 HP: 176 AMPS
• 790/658 HP: 277 AMPS
• 1048/917 HP: 385 AMPS
Harmonic Filter – Logic Board
Power Supply
The low voltage power supplies on the filter logic
board have decreased below the allowable operating
range. The filter logic board receives power from the
VSD logic board via a ribbon cable that connects the
two boards.
Harmonic Filter – Run Signal
When a digital run command is received at the filter
logic board from the VSD logic board (via the 16 posi-
tion ribbon cable), a 1/10 second timer is started. If a
redundant RUN command does not occur on the serial
data link from the VSD logic board before the timer
expires, a shutdown is performed and this message is
generated.
Harmonic Filter – DC Current
Transformer X (1 or 2)
During initialization, with no current flowing through
each DC Current Transformer (DCCT), the DCCT out-
put voltages are measured and compared with a preset
limit via the filter logic board. If the measured values
exceed the preset limits, the DCCT’s are presumed to
be defective and a message indicating which DCCT is
affected (1 or 2) and a chiller shutdown will occur.
SAFETY SHUTDOWN MESSAGES
Condenser – High Pressure
The condenser pressure, as sensed by the condenser
transducer, has increased above 29.7 PSIA. The chiller
can be started after the pressure decreases below 23.7
PSIA and the compressor switch is placed in the STOP/
RESET (O) position.
Condenser – Pressure Transducer Out of
Range
The Condenser Pressure Transducer is indicating a
pressure greater than 35.3 PSIA. This is outside the
normal operating range of the transducer and gener-
ally indicates a defective transducer. The chiller can be
started after the transducer indicates a pressure that is
within range (at or below 35.3 PSIA) and the compres-
sor switch is placed in the
STOP/RESET (O)
position.