Melted wire nut in Hot tub disconnect

Status
Not open for further replies.
D

Dark Sparky

Member
Location
USA
Occupation
Electrical Engineer
Sort of the longer story but I have an apparently failed hot tub disconnect. That was discovered a while back, but now I have another issue in attempting to replace it. The original issue was that upon one of our power outages, the GFI function of the hot tub disconnect ceased working. That rendered the hot tub without power. For about 6 months now it has been wired straight through ( we have not been using the tub) but this allowed it to keep cycling and filtering.

Now I am going to replace the disconnect with a similar one. Upon opening it, I found that one of the wire nuts is melted. Picture attached. This is a 50 amp, 2 pole, breaker. So that should be 240 volt single phase. There are three wires coming from the panel, red, black and white. The same colors run out from the box to the hot tub. The only other aspect is that the red and white wires coming from the hot tub are very short, so there are approximately 12 inch jumpers. It is the connection between the short red wire coming directly in from the hot tub, and the jumper cable, which has the melted wire nut.

I'm hoping this is simply a poor connection, but looking at the thread linked below, it seems like there are some potential other issues?

Insight welcome - I want to keep my family safe!

Potentially similar issue? -

Melting wire nuts

Here is the situation. I can't find the cause. In wiring a bathroom addition the building contractor uncovered many wires in a floor that had been covered up. Some of these were hot some were not. We were able to pull the wires into accessible j-boxes. After all the wiring, the contractor...
forums.mikeholt.com
 

Attachments

  • PXL_20230401_190604136.jpg
    PXL_20230401_190604136.jpg
    1.8 MB · Views: 57
Taking off the wire, not, both wires are very corroded. My gas is that because the one wire coming from the hot tub is so short, rather than stripping it back, it was used as is.

I would welcome thoughts on how to solve this.
 
letgomywago said:
Is there room in the LB to splice just that one after cutting back the burnt part?
Click to expand...
That's a good possibility, I'll check...

First off to Lowe's because I discovered the one conduit entry was apparently glued. Had to cut it off, so now I need to go figure out how to recreate that.
 
It plain and simple was a poor connection that caused it to heat up. Short wire length to work with probably did not help. Always pull on conductors after making up such a connection. If one pulls out of the connection it was a bad connection but at least you caught it before it does something like you ended up with.
 
kwired said:
It plain and simple was a poor connection that caused it to heat up. Short wire length to work with probably did not help. Always pull on conductors after making up such a connection. If one pulls out of the connection it was a bad connection but at least you caught it before it does something like you ended up with.
Click to expand...
This is good advice. Something I've done on 120V home wiring projects, but didn't occur to me as checking this existing installation.

Appreciate the insight, all.
 
letgomywago said:
It's a box adapter you'll need to get a new LB and split it at the entry's with a multitool and screw driver
Click to expand...
I wish I knew what it was. Not sure if it's clear on the photo, but it appeared as if the conduit out the back of the LB continued into the disconnect, and then had a "flange" of PVC that was larger diameter, right inside the disconnect box. That's not really possible (couldn't be installed), but I sure couldn't see where the plastic was glued or would split. There were also metal "rings" on both the inside and outside of the conduit entry (the penetration into the disconnect), tight against the inside & outside, but I couldn't tell their purpose.

I ended up cutting the PVC right outside the box. Bought a short 1/2" to 3/4" electrical PVC adapter, and PVC glue. Planning to use this to reconnect that conduit to the new box.
 

Attachments

  • PXL_20230401_200700239.jpg
    PXL_20230401_200700239.jpg
    1.6 MB · Views: 14
Dark Sparky said:
I wish I knew what it was. Not sure if it's clear on the photo, but it appeared as if the conduit out the back of the LB continued into the disconnect, and then had a "flange" of PVC that was larger diameter, right inside the disconnect box. That's not really possible (couldn't be installed), but I sure couldn't see where the plastic was glued or would split. There were also metal "rings" on both the inside and outside of the conduit entry (the penetration into the disconnect), tight against the inside & outside, but I couldn't tell their purpose.

I ended up cutting the PVC right outside the box. Bought a short 1/2" to 3/4" electrical PVC adapter, and PVC glue. Planning to use this to reconnect that conduit to the new box.
Click to expand...
It is a fitting typically called a box adapter.

1680610223515.png

insert from inside a box or cabinet into socket end of some other fitting like a conduit body or coupling and of course use PVC cement to secure it. Depending on how well it was cemented in sometimes you can cut or chisel one out and not have to completely replace the fitting it was cemented into. If cemented really well it will take long time to chip it all out or you even end up destroying the other fitting.

Metal rings were probably "reducing washers" and were used because the KO was knocked out too large for size of raceway being used.
1680610640362.png
 
Continuing the saga...

To summarize: my original GFI disconnect stopped working one day, seemingly after a lot of power outages that were happening back to back. My electrician tested it and could find no problem with the lines. We decided that the problem must be the disconnect. I spent hours replacing the disconnect (#6 AWG wire is not fun!). The replaced disconnect acts just like the original once it had failed.

Today I completed installing the replacement GFI disconnect. Unfortunately after hours of work replacing it, it is no better than the original. That is - it acts like a mis-wired GFI. The two pole breaker will go fully in one direction (which I assume is "off" ) and only partly in the other direction (which I assume would be "on" ). The test button has no effect.

This is exactly how the original disconnect was acting, prior to me installing this one.

This leads me to conclude that perhaps the problem is not the disconnect. The circuit in its entirety consists of a 50 amp, 2 pole breaker in a sub panel. From there, it runs into this disconnect (located on the outside of the house, opposite the hot tub), and from there underground to the hot tub. It seems unlikely that the wiring itself could have failed. The breaker in the panel seems to be functioning fine. That leaves... the hot tub electronics?

Thoughts welcome. I am ready to hire another electrician, but would like to have an idea about what's likely the cause, especially since the first electrician was incorrect!
 
Dark Sparky said:
Continuing the saga...

To summarize: my original GFI disconnect stopped working one day, seemingly after a lot of power outages that were happening back to back. My electrician tested it and could find no problem with the lines. We decided that the problem must be the disconnect. I spent hours replacing the disconnect (#6 AWG wire is not fun!). The replaced disconnect acts just like the original once it had failed.

Today I completed installing the replacement GFI disconnect. Unfortunately after hours of work replacing it, it is no better than the original. That is - it acts like a mis-wired GFI. The two pole breaker will go fully in one direction (which I assume is "off" ) and only partly in the other direction (which I assume would be "on" ). The test button has no effect.

This is exactly how the original disconnect was acting, prior to me installing this one.

This leads me to conclude that perhaps the problem is not the disconnect. The circuit in its entirety consists of a 50 amp, 2 pole breaker in a sub panel. From there, it runs into this disconnect (located on the outside of the house, opposite the hot tub), and from there underground to the hot tub. It seems unlikely that the wiring itself could have failed. The breaker in the panel seems to be functioning fine. That leaves... the hot tub electronics?

Thoughts welcome. I am ready to hire another electrician, but would like to have an idea about what's likely the cause, especially since the first electrician was incorrect!
Click to expand...
Why are you installing this and not your electrician
 
letgomywago said:
Swapping a hot tub disconnect and these tests should be like 2 hours max
Click to expand...
In the end, the electrician said he did not want to do it. It may have something to do with the fact that the disconnect is located behind a wire trellis. Not a lot of fun to work on.

Between trips to Lowe's, having to cut out the old box, and dealing with very, very short wiring, it took hours. I had to make extra splices because the original wiring coming from the hot tub was extremely short, only stuck into the box about an inch or two.
 
You should find a new electrician

And the control board may be toast if the gfi breaker was toast also. There's other things that could trip it like the heater starting to fail. You can get a hot tub repairman for those parts usually though.
 
letgomywago said:
That's not how you hook up the nuetral on a gfi breaker and an electrician should know. It's in the instructions.
Click to expand...
The electrician did not hook this one up. I hooked it up. The instructions were useless, they included nothing specific to this unit. They covered something generic and entirely unhelpful.

The neutral pigtail had already been connected to the neutral bus at the factory.
 
letgomywago said:
You should find a new electrician

And the control board may be toast if the gfi breaker was toast also. There's other things that could trip it like the heater starting to fail. You can get a hot tub repairman for those parts usually though.
Click to expand...
Sounds like perhaps I should get the hot tub repair man before an electrician.
 
Status
Not open for further replies.
Top