| Article #kba124pmr |
| Troubleshooting for a Phase Reversal (Phase Sequence) Problem |
| Issue |
| I have purchased one of your three phase monitor relays and have connected it per the diagram on the unit. However, I cannot get the unit to operate--it just won't turn on. What's wrong? |
| Solution/Resolution |
Most problems when first installing and applying a three-phase monitor
relay are due to phase sequence issues. Although you may have connected
Phases A, B & C per the diagram on the product, this does not necessarily
mean your three phases are in the same sequence as what the relay is
looking for. The first thing to try when a three-phase monitor does not
work on power up is to switch two of the three wires connected to the
unit.
After all, there are only two true
phase sequence possibilities, so if the initial set-up of A-B-C does not
work, all you have to do is switch the wires coming to the A & B terminals
on the unit (see diagram at right). That should solve the problem.
Remember: it is not required that the phase designation of your system
match the connections to the three-phase monitor relay, i.e., Phase A from
your system to terminal A, Phase B to terminal B, etc.; the connections
from your system must be in the same sequence as what the unit is set up
to use as the basis for offering phase reversal, or sequence,
protection.As always, if you have any problems with selecting, installing or applying any Macromatic three-phase monitor relay, please contact us for immediate help. |
| This article applies to the following Macromatic products: |
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Last Reviewed: 02/27/2006 |