NO switch insulation resistance failure

[Richard Burns]

Any switch that is being run at its rated voltage and current should not experience any flash over, however switches do fail at times.
A common type of failure is for a switch to weld itself closed and therefore could cause the sort of problem you are describing if there are other parts of the circuit holding off power from the switch until a certain point in a process.
For a switch to fail such that it spontaneously conducts I would expect would be rare unless the switch managed to develop point contact surfaces through contact erosion.
However if there are metal dust particles about or frequent arcs on switching generating carbon residue or copper vapour depositing over the enclosure then it may happen.

 

[static zap]

Manual switch ?
Industrial / House hold conditions?
What is the load ? (inductive / lamp / motor - Pure resistance)
..we have barely starter ...!
( Un expected - I would be dusting for fingerprints !)

 

[sysrq]

Any switch that is being run at its rated voltage and current should not experience any flash over, however switches do fail at times.
A common type of failure is for a switch to weld itself closed and therefore could cause the sort of problem you are describing if there are other parts of the circuit holding off power from the switch until a certain point in a process.
For a switch to fail such that it spontaneously conducts I would expect would be rare unless the switch managed to develop point contact surfaces through contact erosion.
However if there are metal dust particles about or frequent arcs on switching generating carbon residue or copper vapour depositing over the enclosure then it may happen.

Another reason why using low voltage ohmmeter alone during troubleshooting is never enough. By using the most basic logic this kind of fault should be resolved in the matter of few minutes.
I wonder how often this kind of fault develops on more dangerous machinery. Couldn't find anything convincing by quick Google search.

 

[sysrq]

Manual switch ?
Industrial / House hold conditions?
What is the load ? (inductive / lamp / motor - Pure resistance)
..we have barely starter ...!
( Un expected - I would be dusting for fingerprints !)

Inductive load in the form of contactor coil.

 

[PEG]

Another reason why using low voltage ohmmeter alone during troubleshooting is never enough. By using the most basic logic this kind of fault should be resolved in the matter of few minutes.
I wonder how often this kind of fault develops on more dangerous machinery. Couldn't find anything convincing by quick Google search.

...Or twenty or so posts,should do it

 

[sysrq]

...Or twenty or so posts,should do it [/

It just was one of those cases when by fixing something else next thing brakes down, that was the reason for confusion. Although the particular culprit was on a completely separate circuit within the machine lacking any wiring diagrams or anything.

 

[PEG]

Nope,sorry,i know less now,than when we started

 

[sysrq]

Nope,sorry,i know less now,than when we started

Early lexicographers made little attempt to match spellings, hence homophones.

 

[ipf]

Early lexicographers made little attempt to match spellings, hence homophones.

Like when Mr Rite had the rite to rite his own funeral rites?
.......rite handed, of course...

 

[PEG]

Early lexicographers made little attempt to match spellings, hence homophones.

No such thing as spelling,with a spoken only language,such as Romanes....and as for bringing ones sexual leanings in to the mix...

 

[ipf]

No such thing as spelling,with a spoken only language,such as Romanes....and as for bringing ones sexual leanings in to the mix...

Never talk phobias on your phone....they'll take you as a phoney phucker.

 

[Chris1234]

I’ve never seen it.
Plenty of Stop buttons (NC) with plastic dust in stopping the machine from working though.

 

[static zap]

New equipment ,or well fiddled with / by unskilled ?
(Touching up plastic parts with a hot soldering iron = FAIL)