Master contactor question

On Sat, 31 Oct 2009 18:38:56 -0500, Dan wrote:

RST Engineering - JIm wrote:
One trick worth trying is to put a pretty good sized (say, 100 amps or so)
load across the contactor when in the closed position and then open the
contactor. The arc thus formed will be enough to melt any oxidation on the
contacts and you will be left with a fresh metal surface nearly as good as
the original.

Do NOT put the load across the line and then turn the contactor on. You
have every chance of welding the contact surfaces together.

Jim




If it's not a sealed unit one can use contact a burnisher.

Dan, U.S. Air Force, retired
But the VAST majority are sealed.

wrote:
On Sat, 31 Oct 2009 18:38:56 -0500, Dan wrote:

RST Engineering - JIm wrote:
One trick worth trying is to put a pretty good sized (say, 100 amps or so)
load across the contactor when in the closed position and then open the
contactor. The arc thus formed will be enough to melt any oxidation on the
contacts and you will be left with a fresh metal surface nearly as good as
the original.

Do NOT put the load across the line and then turn the contactor on. You
have every chance of welding the contact surfaces together.

Jim

If it's not a sealed unit one can use contact a burnisher.

Dan, U.S. Air Force, retired
But the VAST majority are sealed.

I know. It's a pity since the old, unsealed ones, were at least
repairable.

Dan, U.S. Air Force, retired