Volt Drop across a contactor
Volt Drop across a contactor
(OP)
What is the acceptable volt drop across a electrical contactor before replacing it. Never seen a standard spec for replacement.
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Volt Drop across a contactor
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RE: Volt Drop across a contactor
RE: Volt Drop across a contactor
As an example a contact that has a 'relatively' hih resistance may last forever if itonly has a small current running through it. The same contact might fail in a week if instead a large ocurrent is running through it.
Good'ol I*squared*R.
RE: Volt Drop across a contactor
RE: Volt Drop across a contactor
RE: Volt Drop across a contactor
RE: Volt Drop across a contactor
RE: Volt Drop across a contactor
We decided on a "replace contactor" limit after looking on measured values and checking contacts for 30-40 units.
I remember this as a much more reliable indicator than pure resistance measurements or visual check, and we discovered a few bad crimpings and terminations during these tests also. Looking back I think this method was very useful. I do not remember exact value we used...think it was somewhere in the 50-200 mV range with full load, but the best is to do some testing on your own with some representative equipment, and use measurements as reference values.
When mV increases with same load, it is indeed an indicator of worsening contact sets. How good indicator it is will probably be disputed by some...thermal imaging is nowdays very common and very good method for checking continously connected equipment, but with an immense amount of rental equipment to check....and quickly....I still think this old method was pretty good...
RE: Volt Drop across a contactor
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