VYPER
™
VARIABLE SPEED DRIVE
MAINTENANCE
100-210 IOM (
JUL
09)
Page 67
occurrence of this message typically indicates the level of
coolant in the Vyper
™
cooling system is low.
Fault 71: Harmonic Filter Low DC Bus Voltage
Message
Quantum: “Fault 71”
Quantum LX: “Harmonic Filter Low DC Bus Voltage”
The DC link voltage magnitude should remain within -80 VDC
of the bus voltage setpoint determined from the peak input
voltage. If the DC link voltage magnitude falls outside this
range for 100 msec, the unit will trip and the Quantum
™
LX
panel displays Fault 71.
The harmonic filter dynamically generates its own filter DC
link voltage by the interaction of the filter choke and switching
its IGBTs. This DC level is higher than what could be achieved
by rectifying the input line voltage. Thus, the harmonic filter
actually performs a voltage “boost” function. This is neces-
sary in order to permit current to flow into the AC line from
the filter when the AC line is at its peak level.
This particular shutdown and the accompanying message is
generated if the filter’s DC link voltage drops to a level less
than 80 VDC below the filter DC link voltage setpoint. The
filter DC link voltage setpoint is determined by the filter logic
board via the sensing of the three phase input line-to-line
voltage. This setpoint is set to the peak of the sensed input
line-to-line voltage plus 59 volts, not to exceed 760 volts and
varies with the input line-to-line voltage. If this shutdown oc-
curs occasionally, the likely cause is a severe sag in the input
line voltage. Install a power monitor to determine if a power
problem exists. Also, verify the operation of the AC line volt-
age isolator board, by comparing the phase to phase voltage
on J5 pins 1-3. The three voltage measurements should be
almost the same voltage, approximately 5.2 VAC.
Fault 75: Harmonic Filter DC Bus Voltage Imbalance
Message
Quantum: “Fault 75”
Quantum LX: “Harmonic Filter DC Bus Voltage Imbalance”
The one-half DC link voltage magnitude will remain within
± 50VDC of the total DC link voltage divided by two during
the precharge interval for both 60 and 50 Hz 519 filters. If
voltage is outside ± 50VDC, the Quantum
™
LX panel displays
Fault 75.
The one-half DC link voltage magnitude will remain within ±
50 VDC of the total DC link voltage divided by two for both
60 and 50 Hz 519 filters. If the one-half DC link magnitude
exceeds this ± 50VDC window, the unit will trip and the
Quantum™LX panel display s Fault 75.
The Filter DC link is filtered by large, electrolytic capacitors
which are rated for 450 VDC. These capacitors 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 connection, to the negative bus and to
the positive bus. This center point should be approximately
half of the total DC link voltage.
Verify the problem exists using a pair of digital meters, mea-
suring from the series capacitor connection point (wire 525A)
to the positive bus (wire 526A), and from the series capacitor
connection point to the negative bus (wire 524A). When the
filter precharge relay engages, both voltage readings should
register simultaneously with values that is within ± 50 VSD
of each other. If the voltages are equal, check the filter bus
isolator board, the filter logic board, or the wiring/connectors
between the boards. Check the voltages at the input to the
filter logic board, J5 pin 4 to J5 pin 5 and J5 pin 5 to J5 pin
6. The voltages should be approximately equal. If voltage
are not equal, the likely cause is a defective isolator board
or a loose connection.
If the voltages are balanced, the filter logic board is defective.
If the voltages are not equal, check the wiring between the
bleeder resistors 12RES and 13RES and the filter power
module. Also check the value of these resistors. They should
be 3000 ohms nominally. If a problem is not found by perform-
ing these steps, replace the filter power module.
Fault 76: Harmonic Filter 110% Input Current Overload
Message
Quantum: “Fault 76”
Quantum LX: “Harmonic Filter 110% Input Current Overload”
The overload threshold and timer functions reside in software
on the Harmonic Filter’s Logic board. The unit’s three phases
of RMS output current are compared to the overload thresh-
old magnitude. If this threshold is exceeded for 7 seconds
the unit will trip and the Quantum
™
LX panel displays Fault
76. The nominal RMS current trip levels are set at 110% of
the maximum expected RMS input current when running at
100% FLA and are as follows:
•
700/572 – 277 Amps
•
912/752 – 385 Amps
Fault 77: Harmonic Filter Run Signal
Message
Quantum: “Fault 77”
Quantum LX: “Harmonic Filter Run Signal Fault”
When a digital run command is received at the filter logic
board from the Vyper
™
Logic board via the 16-pin ribbon
cable, a 1/10 second timer is begun. A redundant run com-
mand must also occur on the serial data link from the Vyper
™
Logic board via the ribbon cable before the timer expires. If
both signals are not received, the Vyper
™
will be shut down
and this Fault message will be displayed. If this shutdown oc-
curs, check the integrity of the 16-wire ribbon cable installed
between the Vyper
™
Logic board and the Filter Logic board.
If the problem persists, replace the Vyper
™
Logic board.
Fault 81: Interface Board NovRAM Failure
(Warning Only)
Message
Quantum: “Fault 81”
Quantum LX: “VSD Interface Board NovRAM Failure (Warn-
ing Only)”
The integrity of the NovRAM is verified on every power-up.
A known value is written to a specified location in NovRAM,
read back from that location, and compared to the value
originally written. If the two values do not match, the NovRAM
Failure fault is set.
