Largest Load Test Facility in the UK at Quantum’s Repair Centre in Prudhoe
What All Engineers Should Know About
Variable Speed Drive Repairs
I
’m sure we can all agree Variable
Speed Drives are expensive pieces
of equipment that require regular
maintenance to minimize premature
failure and maximize the life span of
your asset.
However, all makes of Drives do fail
and one of the most common faults is
IGBT (Insulated-gate bipolar transistor)
failure. An insulated-gate bipolar
transistor is a three-terminal power
semiconductor device primarily used as
an electronic switch in Variable Speed
Drives.
When a drive suffers an IGBT failure
the best practice is to replace all three
devices, even if only one has actually
failed, as the fault condition more often
than not weakens the remaining devices
which will inevitably lead to a further
premature failure and more costly
downtime for the user.
So far, I’m sure I’ve not told you
anything you don’t already know, but
the real issue with drive repairs is this…
it is imperative that each repair is fully
load tested. This is important because
each IGBT has a free-wheeling diode
8
which you can only accurately be tested
with a full inductive load test.
Most companies that offer Drive Repair
do not have the required load test
facilities and hence they simply carry
out a resistive load test which actually
does not show if the IGBT’s are fully
functioning as a power device.
This leads to a very high percentage of
IGBT drive repairs simply failing again
as soon as they are fitted to the original
application when load is introduced,
leading to another repair cost and more
costly downtime for your process.
In summary all engineers should only
send their valuable variable speed drive
assets to drive repair facilities that have
fully qualified Drive Engineers who have
attended the relevant manufacturers
courses. But also insist that the repairer
has suitable load test facilities, that they
carry out a full load test on your drive
and they give you the option to attend a
witness test or at the very least request a
video of the final test.
Insisting on these simple steps for all
your drive repairs ensures 100% that
Replaced IGBT Modules must be Load Tested
your drive is repaired correctly and fully
functioning before you put back into
service on your plant, thus ensuring
minimum repair cost and minimises
expensive lost production costs.
Quantum Controls have an 8,000 square
foot Drive Repair Facility near Newcastle
with full load testing facilities and are
Official Drive Service Partners for all
major Brands of Drives.
When you next have a Drive failure get
in touch with our expert team for repair
estimate.
Kevin Brown, Owner, Quantum Controls
Email: [email protected]
Tel: 01661 835566