VYPER
™
VARIABLE SPEED DRIVE
MAINTENANCE
S100-200 IOM (MAY 08)
Page 55
Fault 44: Vyper
™
Low Converter Heat Sink Temperature
Message
Quantum: “Fault 44”
Quantum LX: “VSD Low Converter Heatsink Temp Fault”
The phase bank assembly heatsink temperature and the
inverter module base plate temperature are compared to
a lower limit of 37°F. If the inverter base plate temperature
or the converter heat sink temperature falls below 37°F,
the message displayed will be Fault 44. In addition, if both
temperatures fall below the 37°F limit, the unit will trip and
the fan(s) and water pump will be energized. This feature
provides the Service Dept. with a means to run the water
pump while fi lling the cooling system (by pulling VSD logic
board plug P2).
A thermistor sensor is located behind the last SCR/Diode
block on the copper chill plate of the Vyper
™
Power Unit. If at
anytime this thermistor detects a temperature of 37°F (3°C)
or lower a shutdown will occur. In most cases, the problem
will actually be an open thermistor or broken wiring to the
thermistor. The normal thermistor resistance is 10K ohms at
77°F (25°C). Check the circuit for continuity at Vyper
™
Logic
board plug J2. Also, make certain one side of the circuit is
not shorted to the cabinet. Sometimes a thermistor wire can
be pinched against the enclosure.
Fault 45: Vyper Low Current Imbalance
Message
Quantum: “Fault 45”
Quantum LX: “VSD Current Imbalance Fault”
When the average of the three output phase currents (see
section 10.1) exceeds 80% of the 100% Job FLA (see sec-
tion 13.1.6), the % Output Current Imbalance is calculated
using the following equation: [ (
⏐
I
a
-I
ave
⏐
) + (
⏐
I
b
-I
ave
)
⏐
+
(
⏐
I
c
-I
ave
)
⏐
/ {2}{I
ave
}] [100]: I
ave
= {I
a
+ I
b
+ I
c
}/3. If the % Imbal-
ance exceeds 30% continuously for 45 seconds the unit shall
trip and the Quantum
™
LX panel shall display the message
Fault 45. The imbalance fault is disabled when the average
of the three output phase currents drops below 80% FLA.
Fault 46: Vyper Precharge – DC Bus Voltage Imbalance
Message
Quantum: “Fault 46”
Quantum LX: “VSD Precharge DC Bus Voltage Imbalance”
The 1/2 DC link voltage magnitude will remain within
± 88VDC of the total DC link voltage divided by two during
the precharge interval for both the 60 and 50 Hz VSD’s. If not,
the Quantum
™
LX panel will display the message Fault 46.
The defi nition for this fault is identical to “ VSD - DC Bus Volt-
age Imbalance”, except that the fault has occurred during the
precharge period which begins during prelube.
Fault 47: Vyper Precharge – Low DC Bus Voltage 2
Message
Quantum: “Fault 47”
Quantum LX: “VSD Precharge Low DC Bus Voltage 2”
The DC link voltage will reach at least 500 VDC within 20
seconds after the precharge signal has been asserted on
the 60 Hz VSD and at least 414 VDC within 20 seconds on
the 50 Hz VSD. If not, the Quantum
™
LX panel will display
the message Fault 47.
The unit is shut down and this message is generated if this
condition is not met. If this shutdown occurs, measure the
bus voltage at the laminated bus structure, verify the wiring
between the Vyper
™
Logic board and Quantum
™
LX Vyper
™
trigger board, and the input SCR’s, and the DC bus isolator
board and the Vyper
™
Logic board.
Fault 48: Vyper Precharge – Low DC Bus Voltage 1
Message
Quantum: “Fault 48”
Quantum LX: “VSD Precharge Low DC Bus Voltage 1”
The DC Bus voltage must be equal to or greater than 50 VDC
for 60 Hz (41 VDC for 50 HZ) 4 seconds after precharge has
begun. The unit is shut down and this message is generated
if this condition is not met. If this shutdown occurs, measure
the bus voltage at the laminated bus structure, verify the
wiring between the Vyper
™
Logic board and Quantum
™
LX
Vyper
™
trigger board, and the input SCR’s, and the DC bus
isolator board and the Vyper
™
Logic board.
Fault 50: Harmonic Filter High DC Bus Voltage
Message
Quantum: “Fault 50”
Quantum LX: “ Harmonic Filter High DC Bus Voltage Fault”
The harmonic fi lter’s DC link voltage is continuously moni-
tored and if the level exceeds a range of 822 to 900 VDC, a
Filter Bus Over-Voltage shutdown is initiated. Keep in mind
that the harmonic fi lter has its own DC bus as part of the
fi lter power unit, and this DC Link is not connected in any
way with the drive’s DC Link. If this shutdown occurs, it will
be necessary to look at the level of the 460 VAC applied to
the drive. The specifi ed voltage range is 414 to 508. If the
incoming voltage is in excess of 508, steps should be taken
to reduce the voltage to within the specifi ed limits. The cause
of this message will typically be high line voltage, or a surge
on the utility supply.
Fault 51: Harmonic Filter High Phase C Current
Message
Quantum: “Fault 51”
Quantum LX: “ Harmonic Filter High Phase C Current Fault”
The three output lines from the 519 fi lter to the three phase
output inductor are monitored via two Hall effect DC current
transformers (DCCT1 and DCCT2) within the drive. The third
phase is derived using the equation I
f2
= -I
f1
+I
f3
. The unit’s
three phases of instantaneous output current are compared
to a prescribed limit, which is contained in hardware. If any
one of these three signals exceeds the prescribed limit,
the fi lter will be inhibited from operating by inhibiting the
Current Regulator Run signal for fi ve to six input line volt-
age. If any one of the three signals exceeds the prescribed
threshold three times in 60 line cycles, the unit will trip and
the Quantum
™
LX panel will display the message Fault 51.
The peak current levels seen by the IGBT’s under an over-
current trip condition are as follows: 305 Hp (60 Hz) / 254
Hp (50 Hz) = 378 + 59 Amps.
If you experience this shutdown and the Vyper
™
auto-restarts
and continues to run properly with the fi lter operating, it is
likely the fi lter tripped on over-current due to a sag or surge
in the voltage feeding the chiller. If this message reoccurs,
preventing the unit from restarting, you will need to check
the fi lter power unit for shorted transistors. This is done by
measuring resistance from wires 519, 518, and 517 to the
fi lter’s positive bus, checking in both polarities - and from 519,
518, and 517 to the fi lter’s negative bus in both polarities.
None of the readings should be less than 5 ohms.
