User Manual - Rev AJ
California Instruments
7.4.6 Other No Output Conditions
If one or more outputs (phase A, B or C) do not produce an output, it may be caused by an
amplifier failure. Amplifier failures can either be input (PFC) or output related (Amp). To
determine if this is the case, the cover of the amplifier has to be removed. Contact customer
service
before attempting to diagnose on your own.
ink
, the PFC power devices must be replaced. If not, they need to be
checked for continuity using a DMM or diode checker.
e
drive section of the board and the board itself may have
to be replaced. MX Systems with later generation 7003-716 PFC control boards generally will
only require replacement of the 2A gate fuses to restore functionali
I
ks intact, o
witches ay have shorted.
The usual scenario is one or two of the IGBT
s
if the B+ device
short. When these devices
short, one or more of the 30A fuses (F1 through F8) on the DC power distribution board will be
open.
An amplifier device failure is not audible at all so there may be no indication of this other than
checking as follows:
1. Measure the output voltage with Zero AC volts programmed.
2. Remove any EUT from the o
3. Turn output ON and measure
ould
4. If the output reads –225VDC on the low range and close to 0 Vdc on the high range, then it
is almost certain that th
s
ices are shorted.
Note that the measurement screen will not report the DC faulty output voltage in the AC mode,
as the measurements in this mode are AC coupled. Therefore, it is necessary to measure at the
output terminals with a DMM to determine the actual output. Alternatively, the MX45 can be
switched to AC+DC mode in which case the internal measurements can be used instead.
If it is determined that it is an amplifier failure, the affected IGBT's need to be replaced. If no
local service support is available, the amplifier may be exchanged completely. Contact customer
service
PFC failure denotes one or all three of the IGBT power modules on the large PFC heat s
have shorted, and damaged the devices. This type of failure is sometimes accompanied by a
popping sound as the large PFC power devices give out. To diagnose this failure mode, the
amplifiers must be removed and the cover removed for inspection.
If there is any sign of damage
In case of a PFC failure, older generation PFC control boards (7003-705 or 7003-712) may hav
sustained damaged in the isolated gate
ty.
f the PFC section loo
ne of the output amplifier s
m
switch devices on one of the 4 heat sinks get
is failed, the B- device will also
horted. Usually
utput connections.
the AC and DC output. It sh
be close to zero.
e fuse i blown and 1 or 2 IGBT dev
for module exchange information.
7.5 Factory Assistance
If the problem with the cabinet or one of the power modules cannot be isolated, contact the
factory for assistance.
MX
Series
180