Power, Grounding, Surge Protection for Industrial, Factory, & Laboratory
Applications
Think of power going into your electronics as putting food
into your body. If you put bad food in your body then you'll get sick!
If you put bad power into your electronics then you will have
problems. If you
want a stable, error free process, then clean up the power before it gets to
your equipment.
There are several layers of protection:
Circuit breakers and fuses protect in case of shorts. If you have
three phase power it is important to make sure all three phases are
disconnected if only one phase shorts.
Surge suppressors
Isolation transformers
Noise filters
Reactors
Uninterruptible Power Supply (UPS)
Circuit breakers and fuses perform the same function so you don't use both.
Also you can have several layers of circuit breakers / fuses -- on each piece of
equipment, on the machine, electrical branch, area power, etc.
Isolation transformers, noise filters, and reactors perform the same
function so typically only one of these is used.
One important thing to think about is how important is noise suppression
in a specific application. For example, if an application only has
discrete inputs and outputs that are all 120 VAC (no analog) then it probably
does not make sense to spend a lot of money on noise suppression. However,
on systems with both variable frequency drives and accurate analog I/O, we install
considerable filtering on the drives and the control system to keep them
isolated and reduce the noise as much as possible.
Links
Acopian -- (AC/DC and DC/DC) Power
Supplies including 24 VDC power supplies
Use fuses and circuit breakers liberally. This protects the
equipment, users, facilitates troubleshooting, and minimizes potentially
dangerous situations.
Power is like putting food into your body. Clean up power to
reduce problems.
Follow good grounding practices.
For control systems, use a surge suppressor, isolation transformer, and
Uninterruptible Power Supply (UPS). Your control system will have
fewer "glitches" and you'll have fewer problems.
Any cables that go outside should have lightning protection.
The more accurate the signal you are trying to measure -- the more you
need to do to clean your power.
Motors and drives are the
worst at generating noise. Use (preferrably) EMI filters or at least
reactors to minimize the noise.
Do you like "phantom" problems that occur when you least expect
it? Do you like getting pressure calls at night and on the weekends?
A lot of people won't pay for proper grounding, isolation transformers, noise
filtering, surge protection and other items listed on this page because they can not see all of
the problems that they eliminate. Follow the ideas presented on this page
and you will find that many difficult to diagnose problems are eliminated.
We try to offer a fair and balanced opinion on every
page of our website. We would appreciate more
information from other users to express their opinions which we will
then incorporate. If you have questions or comments please post them
on our message board (see button in left hand column) so that others can
read and benefit.