amprobe heating up dimmers burned out

[hotwire62]

I am trying g to check out a friends house which burned out some dimmers after a power outage, I checked all connections in main and sub panel and voltage and frequency are normal , when I plugged in my amprobe insp 3 it started smoking and it did this on more than one circuit ,I tried plugging it in at my house and it won't do the voltage drop test any.ore,I was hoping to use the tested to check the wiring but now it won't work but lights in the house are working fine , any ideasof what's going g on

 

[John120/240]

Have you checked from hot to neutral at your switch box ? Or ahead of this junction ?

 

[ActionDave]

I am trying g to check out a friends house which burned out some dimmers after a power outage, I checked all connections in main and sub panel and voltage and frequency are normal , when I plugged in my amprobe insp 3 it started smoking and it did this on more than one circuit ,I tried plugging it in at my house and it won't do the voltage drop test any.ore,I was hoping to use the tested to check the wiring but now it won't work but lights in the house are working fine , any ideasof what's going g on

Why test for frequency on the main of a house?

I think your amprobe insp 3 was cooked the first time it started smoking. I don't have an amprobe insp 3, I don't know what it is, but if it started smoking I wouldn't use it any more.

I doubt the problem in the house was voltage drop.

The lights are working fine. Are the dimmers working fine?

 

[GoldDigger]

I think your amprobe insp 3 was cooked the first time it started smoking. I don't have an amprobe insp 3, I don't know what it is, but if it started smoking I wouldn't use it any more.

The INSP-3 is a combination function unit which plugs into a receptacle via a three-wire cord and in addition to polarity, voltage and GFCI function testing it measures voltage drop in all wires using a built in controlled load.

User selectable 0, 10, 15 and 20 amps loads to verify performance of the electrical system

My guess is that either the unit just happened to fail or that a bad neutral condition caused the internal load to try to pull 20A from a 240V source voltage and the quadruple-normal power smoked the load resistor(s).
The rated operating voltage of the unit is 95-140VAC. Even if it has protective circuitry designed to monitor the applied voltage before engaging the internal current load, that circuitry may have seen a close to normal voltage until it actually tried to send significant current through the impaired neutral. A neutral which opened only when subjected to high current could have caused the applied voltage to jump from near 120V to near 240V depending on what other loads were present in the system at the time.
Or it just may not be protected against 240V input in the first place.

From the manual:

The INSP-3 wiring inspection Tester is conformed
to EN61010-1:2001; CAT II 120 V, class II and
pollution deg.2

Do not exceed the maximum overload limits
(see specifications) nor the limits marked on the
instrument itself. Never apply more than 120
VAC rms between the adaptor prongs of the
wiring inspection tester.

 

[ActionDave]

The INSP-3 is a combination function unit which plugs into a receptacle via a three-wire cord and in addition to polarity, voltage and GFCI function testing it measures voltage drop in all wires using a built in controlled load.


My guess is that either the unit just happened to fail or that a bad neutral condition caused the internal load to try to pull 20A from a 240V source voltage and the quadruple-normal power smoked the load resistor(s).
The rated operating voltage of the unit is 95-140VAC. Even if it has protective circuitry designed to monitor the applied voltage before engaging the internal current load, that circuitry may have seen a close to normal voltage until it actually tried to send significant current through the impaired neutral. A neutral which opened only when subjected to high current could have caused the applied voltage to jump from near 120V to near 240V depending on what other loads were present in the system at the time.
Or it just may not be protected against 240V input in the first place.

That would explain the smoke coming out. That would not explain checking more than once to see if the smoke would stop coming out.

 

[GoldDigger]

That would explain the smoke coming out. That would not explain checking more than once to see if the smoke would stop coming out.

If you keep it up long enough, either the smoke will stop completely or it will be replaced by flame.

 

[PetrosA]

I was told by Steve at Tasco (the manufacturer of the INSP-3) that the units will withstand 240V as they are designed to work in both N. America and Europe. Try calling them (phone number's on the website) and ask one of the engineers. It would be helpful if you tell them what the voltage was and any other details from when it happened.

 

[hotwire62]

I don't know why I would test the frequency thats why I'm asking someone who is probably a better troubleshooter than I, I did test the voltage from hot to neut and hot to ground at receptacle where my insp3 started getting hot and the voltage was normal about 120v, I plugged the insp3 in a different circuit to see if the problem was isolated to that one circuit what would you do just throw it away, as far as the dimmers go there were two that weren't working and I replaced them and now they work.

 

[hotwire62]

I don't know why I would test the frequency thats why I'm asking someone who is probably a better troubleshooter than I, I did test the voltage from hot to neut and hot to ground at receptacle where my insp3 started getting hot and the voltage was normal about 120v, I plugged the insp3 in a different circuit to see if the problem was isolated to that one circuit what would you do just throw it away, as far as the dimmers go there were two that weren't working and I replaced them and now they work.

I also tested phase to phase and hot to neutral at the main service and subpanel and all was normal as well as making sure all neutral terminals were tight, there was no sign of arcing.

 

[RLyons]

I had to have mine replaced after hitting the AFCI test one to many times on a GFCI circuit :slaphead:....no smoke though it did indicate on the screen it needed to be repaired. I don't know how much I trust this thing as you plug it in and it says it fails voltage drop then you unplug it and plug it in again and it passes. On GFCI circuits you are suppose to hit the GFCI test button before plugging it in so it gives you polarity and voltage drop then instructing you to "hit GFCI" to test. Allot of the times it just trips the GFCI and doesn't give me the polarity and voltage drop. Another weird thing I came across was a GFI recept that didn't trip when I hit the test button or when using a plug tester the isp3 tripped it and said the gfi was working properly.

 

[ActionDave]

I don't know why I would test the frequency thats why I'm asking someone who is probably a better troubleshooter than I, I did test the voltage from hot to neut and hot to ground at receptacle where my insp3 started getting hot and the voltage was normal about 120v, I plugged the insp3 in a different circuit to see if the problem was isolated to that one circuit what would you do just throw it away, as far as the dimmers go there were two that weren't working and I replaced them and now they work.

I have never seen one of these testers but after reading this thread I am in no hurry to buy one. I think you should try and get your money back.

The other checks you did are the same ones I would. Sounds like the power outage had something to do with the dimmers failing and replacing them was the appropriate action.

 

[StarCat]

Test Instruments

Test Instruments

I would agree with not rushing out to buy some of the " new " tek thats out there.
Out of 3 recent past purchases I have secured from Extech, Amprobe, and Fluke, all contain engineering defects that seem to be a sign of the times.
I really have to wonder who these guys are trying to kid with such shoddy products.
I have some older generation gear thats infinitely more reliable about giving accurate readings.

 

[cowboyjwc]

So back to the OP, my guess would be that when the power came back on, it surged just enough to burn out the dimmers.

Also remember that smoke=electricity, when all the smoke is gone the device will no longer work.

 

[readydave8]

I like my Tasco Inspector (might be II instead of III) because of all the red and green lites, on voltage drop I can select loads and change lite pattern, makes the homeowner feel like he's getting hi-tech evaluation. But when no one's watching I usually use wiggy-style vol-con, I can check for polarity and trip GFCI's with it.