Possible crackling noise from outlet?

[Caddybill]

Some background. Last bad rain storm, my wife calls me at work in a panic crying. She said she just called the Fire Dept. because she thinks she heard a cackling noise from our dedicated AC outlet. FD shuts breaker to the outlet B4 I get home. We had a leak from a window just above this outlet but when I checked it the outlet was dry.
Power has been turned of to this line since
I just got around to fixing the leak and am now checking the outlet again. First I disconnected the hot and neutral from the panel then I checked for continuity to either the hot to neutral or neutral to shielded cable and visa versa. Did not find a problem.
Then I checked the outlet. Pulled the receptacle out and it looks good, no evidence of arcing.
Does anyone have any suggestions of what to check next?

 

[Jlarson]

Replace the receptacle.

And you have shielded cable running to your window shaker? That's weird.

 

[raiderhillbilly]

I would also replace the outlet. I have recently started buying the Commercial grade ones at Lowes or Home Depot. They are much better built.

 

[Caddybill]

Replace the receptacle.

And you have shielded cable running to your window shaker? That's weird.

In NYC shielded cable (BX) was code until last year.

 

[Caddybill]

I forgot to mention that the AC was NOT plugged in at the time.

 

[CNGsaves]

Is this a 120v or 240v run for the air conditioner??

+1 to replace outlet and examine wires closely on both ends . . . thus check out the breaker panel side as well. What size of wire and distance to breaker box?? What size breaker for this AC?? What amp draw is shown on AC unit??

Sparkies will give you all the details if you provide enough information. Good luck.

 

[Jlarson]

If you are still concerned after replacing the receptacle or don't want to handle it yourself have an electrician come out and do a insulation resistance test on the circuit. More then likely there is just internal damage to the recep.

In NYC shielded cable (BX) was code until last year.

That's not shielded cable. BX is just trade slang for plain jane armored cable.

 

[Caddybill]

Is this a 120v or 240v run for the air conditioner??

+1 to replace outlet and examine wires closely on both ends . . . thus check out the breaker panel side as well. What size of wire and distance to breaker box?? What size breaker for this AC?? What amp draw is shown on AC unit??

Sparkies will give you all the details if you provide enough information. Good luck.

120v. Wire size is 12. Looks to be about 30ft to panel.15 amp breaker.
AC was not plugged in at the time.

 

[Caddybill]

If you are still concerned after replacing the receptacle or don't want to handle it yourself have an electrician come out and do a insulation resistance test on the circuit. More then likely there is just internal damage to the recep.

Is that what a megomeater is used for?

 

[Jlarson]

Yes, megger, megaohmeter, megameter... all names for an insulation resistance tester.

 

[sberry]

because she thinks she heard a cackling noise

I may have found the problem.

 

[Caddybill]

I may have found the problem.

We're on the same page. I'm not sure what she heard and I'm not finding any evidence of a problem. Except for the water leak near the outlet.

 

[sberry]

I remember a problem in a bar once where the wall sheet was stainless, I cant recall exactly what happened but it involved a spark 3 ft long. It probably did look frightening and scared the **** out of the help but the 3 ft might of been a bit of a stretch. .

 

[rlitman]

Yes, megger, megaohmeter, megameter... all names for an insulation resistance tester.

Exactly what I was going to say as I read down this thread. Checking for continuity with a regular multimeter won't tell you much, because the voltage used for testing is so very low.

 

[sberry]

That's just a story but it is comforting to know there are several masters here, some of these guys run million dollar jobs and are hi level trouble shooters in case my guess is off.

 

[Caddybill]

This might be the excuse I need to get a Megohmmeter. I've looked at them before but I did not know what specs to look for. I work in the gas and oil heating field, doing installation and service. Can anyone recommended a reasonably priced one that would suit my needs?
In order to check the wiring in my case is the megohmeter used the same way I would check for continuity between the wires with my DMM ?

 

[wyliesdiesels]

That's not shielded cable. BX is just trade slang for plain jane armored cable.

Exactly. Shielded cable is for noise filtering....such as STP CAT 5e

This might be the excuse I need to get a Megohmmeter. I've looked at them before but I did not know what specs to look for. I work in the gas and oil heating field, doing installation and service. Can anyone recommended a reasonably priced one that would suit my needs?
In order to check the wiring in my case is the megohmeter used the same way I would check for continuity between the wires with my DMM ?

A megger uses high voltage and u really need to know what youre doing with it. I would suggest if u buy one to really familiarize yourself with it and get some training on it.

Fluke makes some good models. Depends on what features u need!

 

[404]

A megger uses high voltage and u really need to know what youre doing with it. I would suggest if u buy one to really familiarize yourself with it and get some training on it.

Fluke makes some good models. Depends on what features u need!

Also, to my surprise, A megger can leave a high voltage charge in a length of cable. I was testing a length of cat 5 for fun, and minutes later picked it up and touched the bare ends.. boy did that hurt.

 

[Jlarson]

This might be the excuse I need to get a Megohmmeter. I've looked at them before but I did not know what specs to look for. I work in the gas and oil heating field, doing installation and service. Can anyone recommended a reasonably priced one that would suit my needs?
In order to check the wiring in my case is the megohmeter used the same way I would check for continuity between the wires with my DMM ?

Unless you are an electrician or a test technician that is going to use it every day to troubleshoot, do PM's, timed tests and recording a SUPCO M500 is a good go-no go tester. Just about every HVAC house sells them.

 

[sberry]

You don't need one. Right off hand no one I know has one. This is a tool for an expert specialist.

 

[TheEquineFencer]

LOL... I know another tech that went to a job to do the start up on 26 Automatic Transfer Switches...all 26 were bad. Turns out someone disconnected utility power and generator power and megged the system...it fried all the PC Boards in each ATS. Be careful with a megger.

 

[LS6 Tommy]

I have a megger. All my HVAC compressors get megged and the results logged annually.

That being said, most of the meggers designed specifically to test HVAC compressor motor windings have lower voltage output than the ones used for the heavier duty electrical testing stuff. Less chance to burn up a winding.

Tommy

 

[Caddybill]

I have a megger. All my HVAC compressors get megged and the results logged annually.

That being said, most of the meggers designed specifically to test HVAC compressor motor windings have lower voltage output than the ones used for the heavier duty electrical testing stuff. Less chance to burn up a winding.

Tommy

What specs would I look for to check out household wireing?

 

[LS6 Tommy]

What specs would I look for to check out household wireing?

I'll take a "pass" on that and pose the question to our more qualified guys that are actually electricians.

Tommy

 

[rlitman]

LOL... I know another tech that went to a job to do the start up on 26 Automatic Transfer Switches...all 26 were bad. Turns out someone disconnected utility power and generator power and megged the system...it fried all the PC Boards in each ATS. Be careful with a megger.

Gasp! Yeah, I'd expect that was an expensive mistake. A megger is fine for testing out parts like the outlet in question (on an insulated bench), or circuit breakers, or coils, but certainly not for an ATS.

The worst part is, as it fried the boards, it should have shown some continuity. That alone would make all but the biggest of idiots stop before frying the third one. But 26...

Mine tests at 500, 1000 and 2500 VDC. Note that 500VDC is hardly much of a test for 480VAC equipment. It's Chinese **** I got for $40, so I put on my 15kV gloves before using it (because I don't trust it as far as I can throw it). But in my case, it saved me from trashing two $500 circuit breakers, so it has paid for itself.

Back to this thread. If you suspect an outlet was damaged, REPLACE IT. Don't test it with a megger that will cost you as much as several cases of outlets. NO, water has not damaged the insulation of the wiring (unless you have cloth covered wires). The only potential issue is with the receptacle, so just replace it and move on.

 

[Caddybill]

Back to this thread. If you suspect an outlet was damaged, REPLACE IT. Don't test it with a megger that will cost you as much as several cases of outlets. NO, water has not damaged the insulation of the wiring (unless you have cloth covered wires). The only potential issue is with the receptacle, so just replace it and move on.

No question at all, I will replace the outlet. I had planed to do that all along. But i would like to rule out any problems with the wireing before going through the trouble to run new wire to 2nd floor.

 

[rlitman]

Ok, but THHN insulation is rated for use inside wet conduit. Sure, water will corrode BX sheathing, and I'd recommend it be kept dry, but the reality is that if you have solid wires with plastic insulation, water will not harm the wire.

 

[sberry]

It would be cheaper and easier to run a new wire but its so rare that there is a problem with it that its near some lucky loto numbers. You are fishing unless you definitely know someone pounded a nail thru it, if you still feel this way get afci breaker and stick on it but you plain aint got no business with a megger pretty much period.
This is a device for a professional not one for someone writing a DIY forum cause the wife thinks she heard a cackle in an outlet and needs trouble shooting help,,, to top it off some well meaning professional mentions megger and while they are experts the advice is amateur for even introducing a megger to this conversation.

 

[Kevin54]

Replace the outlet, and kudos to the wife for calling the FD. Our neighbor had a similar incident a few years back during a big storm. She called me and asked what to do. I told her to call the FD, and they can come with a thermal imaging camera and check the walls. One outlet was smoked, and her phone, VCR, TV, and some other electronics were fried. Luckily, there was no other damage. But that is what the fire department is for. They would rather check things out and find nothing than get a call and have to fight a huge fire.

So replace the outlet, and take the wife to dinner. She at least knew to do the right thing and possibly prevent a larger catastrophe.

 

[rlitman]

Replace the outlet, and kudos to the wife for calling the FD. Our neighbor had a similar incident a few years back during a big storm. She called me and asked what to do. I told her to call the FD, and they can come with a thermal imaging camera and check the walls. One outlet was smoked, and her phone, VCR, TV, and some other electronics were fried. Luckily, there was no other damage. But that is what the fire department is for. They would rather check things out and find nothing than get a call and have to fight a huge fire.

So replace the outlet, and take the wife to dinner. She at least knew to do the right thing and possibly prevent a larger catastrophe.

Now THATS a great idea. Forget the megger, buy a FLIR.

Actually, the fire department is a good idea. Many (most) have FLIR cameras. If they're nice enough to bring it to check out your walls, that would be a great test.

But again, a little water isn't going to hurt the wires in your walls (unless they're stranded copper, or use cloth insulation). Now in the case of lightning damage, checking your wires with a megger, and/or a FLIR makes good sense.

 

[Caddybill]

It would be cheaper and easier to run a new wire but its so rare that there is a problem with it that its near some lucky loto numbers. You are fishing unless you definitely know someone pounded a nail thru it, if you still feel this way get afci breaker and stick on it but you plain aint got no business with a megger pretty much period.
This is a device for a professional not one for someone writing a DIY forum cause the wife thinks she heard a cackle in an outlet and needs trouble shooting help,,, to top it off some well meaning professional mentions megger and while they are experts the advice is amateur for even introducing a megger to this conversation.

Tjanks for your responce. No offense taken, but I'm not just some DIY guy. While I am far from being an electrician I do have more than 10 years in the oil and gas heating business as a service mechanic . I posted here on this forum rather than on of the pro forums I belong to, because I like the vibe of this place.

 

[sberry]

I agree guys have a lot of experience and are often capable but are not sure, this I understand and the are a judgment call which of often difficult and not always clear. A service electrician has a different view than other types and sees this regular and figures out early on if someone hit the panic button and if there is a real likelihood there is a problem.
These types of questions are like many other, the ones that come to mind are usually where someone wants to spin off from the norm especially in a common garage or residential setting,,, and often have a tint of,,, if you have to ask flavor, imagined or not.
We get questions about plugs and connectors like this,,, usually started with, "whats the best" followed by I don't want to spend.
I do a lot of self comparison, chances are if I don't need it then someone else asking probably doesn't either. I don't have 100A sleve and pin connections and Bill who is setting up his garage probably doent need them either and while one tries to think of every conceiveable app the world had ever come up with the reality is standard 50A are adequate for moist people and the likelihood they have several pieces in a home garage with 100A demands is about nill and should a guy get a 300 tig for free hard wire is so easy and he is not likely to put several 100 in to a connector he really doesn't need.

 

[sberry]

Most electricians service vans do not carry a megger.

 

[rlitman]

Most electricians service vans do not carry a megger.

Reminds me of something that happened to me years ago.
I was tracking down an internal evap leak in my Jeep, and narrowed it down to two possible parts. At the dealership parts counter, one was cheap and in stock, the other was expensive and special order. Before I ordered the expensive one, the helpful counterman pointed out that if they don't have it, I probably don't need it.

 

[Jlarson]

Only reason I recommend meggering is because he says he has armored cable and we don't know the vintage it. It's our policy to megger any armored cable that isn't the modern stuff with the bonding strip. The old stuff would often allow faults to go on sometimes for ever and heat up baking the conductors.

Newer AC, MC, NM or THWN in conduit I just replace the device. We probably replace about 3-5 devices a week in wash down environments in manufacturing plants. If you do service in restaurants and commercial kitchens it becomes one of your main functions.

 

[sberry]

I missed the metal cable part. To tell the truth if it was mine and humanly possible it would get a new cable pulled. That's just me though, I replace where I can. Not always due to a fault but simply to out old obsolete wire.
I was watching TOH and now they got a couple sparks on there. They were adding an addition that was worth more than the core and tying on some old alum wire and he was showing the right way,,, ****, I would have had a tuff time leaving that alone.

 

[sberry]

I have as much error as anyone, maybe more due to the variety of what I do and I post a few things that get me labeled hack but I replace a lot of old stuff. A lot I don't intend to once I start.
I got caught in 2 repairs I missed last week, one a tire should have been out a long time ago and its rare I shove something off cause I cant afford it. Have added a lot of circuits and added them behind contractors too.
Saw one the other day, sold a service upgrade they didn't need (should get a pic of this) and left the real work they did like 2 new kitchen top and fridge circuits, now all piled on one and a fault in a switch circuit near a hot tub.
I heard this outfit retired recently, so long.