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Re: Window Screen Tamper



"Jim" <alarminex@xxxxxxx> wrote in message
news:67e77a2b-22a8-4d30-b270-2e046235a672@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
On May 23, 10:12?pm, "ABLE1" <royboynos...@xxxxxxxxxxxxx> wrote:

>
> By a 'Hipot Tester' ?you mean a Megger(brand name). ?I have used a Megger
> to
> test insulation on motor windings to ensure the resistance is within
> correct
> values after a motor re-wind and it did not have any possible shorts to
> the
> motor case. ?It may work in this case but I would think it is
> questionable.
> I say this because it would seem to me that the insulation at the point of
> failure would have to be in close proximity to the frame if not touching
> it.
> That being said, how can this be assured inside of the frame?? ?Then again
> maybe a tolerance value can be developed if you do enough QC and a bell
> curve can be produced. ?The voltage on the contacts would not be an issue
> unless it is directly shorted to the frame.

> I'm not so sure about that. If there is any resistance ( which there
> will be) across the contacts of the reed, the Hypot could cause an arc
> and either burn or weld the contacts together.


Actually no.

When you connect the Megger leads you would connect to the metal frame and
the end of one wire lead.  There is no current flow................. unless
there is bad wire insulation and a short is produced to the frame at the
high voltage potential.  It all happens when you turn the crank.  If all is
in good condition the needle never moves since no current flows.

If current does flow and the reed is destroyed.............. well it was a
bad set up to start with so it makes little difference.

Of course the test needs to be performed with the tamper magnet in place to
keep the switch closed, otherwise you are only testing one side of the loop.




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