We purchased a home last year and it has a detached garage in the rear of the property. We have a 30amp breaker for the rear garage sub panel. Inside the the garage has its own sub panel with multiple breakers. It has two 220 breakers, one for an air compressor and an older style 220 plug for an old table saw.

We have had no problems with anything....until today. None of my light switches work. I reset the main breaker for the garage and also all of the breakers in the sub panel. I checked all of my connects and they are all tight, also reset all of my GFI plugs.

Only one side of the garage works and those are the plugs only. Something that is strange is that if I flip the switch that is on the air compressor which is 220v. The compressor does not turn on but sounds like it wants to turn over, and the kicker is that with the air compressor switch on the ceiling lights turn on. I unplug the compressor from the wall and it did not make a difference in making the lights work.

What the heck is going on? Is it a possible bad breaker kicking back into the bus? Any and all help is appreciate.

 

It's 240 not 220. It sounds like you lost one leg of the 240. Measure the voltage across the breaker supplying the subpanel and at the main breaker in the subpanel. Do you get ~240v?

 

Thank you for the quick response. As you can tell I'm new to electrical. I will check tonight when I get back home

 

So I checked the lines coming into the sub panel in my back garage and one line has 12v and the other is dead

I went to the panel in the front of the house and checked the wires that feed the back garage and both the wires on the 30amp breaker each show 120v totaling 240v. Looks like it is safe to say that the dead line is broken somewhere?

It looks like they ran the lane from the house box into the attic and then across the house and down throw PVC into the ground and then it runs about 150FT underground to the back garage.

What a nightmare. Any suggestions?

Also what guage wire would you run for 240v on a 30amp breaker for a spand of about 200ft or so.

thanks.

 

You missed the main test. You must measure between the two terminals on the breaker.Probably #8 but #10 would work if the load was small enough. What is in the PVC? If cable what is the color of the outer jacket?

 

I did test the 30 amp breaker at the main box on the house. It shows 240v.

When testing the lines where they hook up to the subpanel in the back garage only one shows power, the black line.

The current wire that is ran from the breaker at the front of the house is 2 white wires and one black wire. It appears that they colored the end of one wire red both at the main box at the hoouse and also where it connects to the sub panel in the back garage (which is the dead line. )

Thanks again for all of your help. I'm just not sure why the line would suddenly go dead? We did have a crazy ran storm follow by a 4.6 earthquake the next day.

 

So they used individual wires from the house to garage? What did they use to run through the house? Have you tested voltage where they converted from cable to individual wires?

Note: If individual wires to garage the wires do not meet code probably in force at time of installation assuming #6 or smaller because a white smaller then #6 can't be remarked as an ungrounded conductor (red). It is not code under current code because you don't have a ground. I'd suggest running new wires. That leaves the question of the inside wiring.

 

Thanks again for the help. The wires are individual wires from box at the house all the way to the sub panel in the back garage. They are thick but I can't made out the awg writing. They are ran inside of metal flex conduit starting at the house and then PVC conduit once it exits the house.

When running new would you recommend 8-3 uf? Is a ground required ? There is a 8ft deep ground rod at the sub panel in the rear garage.

Was thinking about putting the new cable in schedule 40 PVC conduit that should be ok and overkill right? I never want to mess with it again.


Think maybe just digging a new trench would be easier then trying to pull the cable?

 

It would be over kill and not needed plus very difficult to pull. Individual THWN, two black, one white, one green will be fine. I'd suggest 8-3 NM-b (Romex) through the attic and then #10 THWN (two black, one green, one white) to the garage (assuming a distance of less then 150 feet between garage and house).

You may be able to use the Cable in the attic if it is at least #10 and 3-conductor.

If you don't have a ground bar in the subpanel you will need to add one and you will need to isolate the neutral bar and move all grounds to the ground bar.

 

I just got off the phone with the previous owner of the home. We still stay in contact. He told me that when he had the garage in the back built they ran 6# wiring from the front panel all the way to the back. In the attic it is in flexible metal conduit and in the ground it is in PVC conduit. I'm not sure how this could have broke.

He suggested that I switch the two wires at the subpanel. And then power the system up. Then see if the same wire that was showing dead before still showing dead. What do you think?

 

So there is no electrical connections where the FMC meets the PVC? How did they connect the two conduits?

Yes turn the breaker off and disconnect the feed wire. Turn the breaker on and measure the voltage between them and from each one to neutral.

Not relevant to the problem but you should consider bringing this up to code.

 

He said there is a junction box in the attic where the pvc conduit and the metal flex conduit come together. I will have to get up there later tonight to check it out.

You say it is not upto code. why? the garage was built in 1986. Not sure why it is not upto code. Here is a picture of the sub panel in the garage, The red wire going into the panel is the dead one.



The previous owner also worked for a telephone company and mentioned that there is a tool that can send a signal down the line and it will tell you how far away the break in the line is? every heard of anything like this?

 

• Nine circuits no disconnect. More then six circuits requires a disconnect at the subpanel (six throw rule). Probably not code compliant even in 1989.
• No ground wire, no separate ground bar, bonded neutral bar (guess, can't see). Grandfathered but not up to current code.

There is but it doesn't do any good. No way to splice the break since it is in conduit. Once you know a wire is bad you have to pull it out and replace it.

 

Couple of questions. I'm trying to make this as easy on myself as possible.

Would you just pull the one #6 wire that is dead and replace it with another #6 wire? My concern with this is damaging the other 20 wires in the conduit, the strap on the wall says its 1 1/4 pvc conduit. Also I'm not sure if there is a break in the existing conduit that cause the wire to fail in the first place?

What is the best way to go?

 

There should be three wires in the conduit based on you picture. What 20 wires?

 

20 that was a typo, meant 2. I fixed the issue today. I found a "hidden" junction box where the wire came into the house above the patio. I had to remove a 2x8 fireblock to get the front cover off of the junction box. I felt so lucky to find that one of the wires came out of the wire nut!! Back to full power. Sucks i spent so much time in the attic sweating

 

Good job. You need to make sure that box is permanently accessible. When you have time you can bring the subpanel up to current code. Do you have a make and model number for the subpanel?

 

The box up by the roof is about 2 inches wide by 5 inches in height. It is such a tight fit for the connections with the wire nuts. Is there something that is very secure but more streamline? I would like to replace the box but the roof of the patio and fascia of the house are in the way. I can access the box but it is very tight.

I would love to use these, but not sure they will fit in the small box.

http://www.polarisconnectors.com/pdf...ISR_series.pdf

ISR-1/0 I believe is the one I would need, need three of them.


Lastly is there an extension for the box I have to make it deeper? Or a deeper lid?

Thanks for the help with advice about the connectors.

 

I wondering if something like this would be better and smaller then the wire nuts? the big plug wire nuts take up so much space in the little box.

Amazon.com: Gardner Bender HSB-28 Butt Splice Kit: Home Improvement

would need three of them.

 

It would work. Choice is up to you.

 

I know these are made for automotive use, but would they work also? they are $6 vs $10. I could put some shrink tubing over them.

Stinger SPT5211 Coupler 4 Gauge Power Wire Terminal Splice Chrome Input Output | eBay

 

No. If they are not rated for at least 240v/60a they can not be used.

 

I went ahead and bought these and some heavy duty shrink tubing. I should be ok to use these right? they seem to be rated for what I'm doing.


http://www-public.tnb.com/ps/fulltil...i?part=ASR0214

 

If it was my choice I would just use big blue wirenuts. However, you're last post is OK too.

As for Ray's "What is this?" in the picture, those are cover stand offs or cover adjustment screws. They are normal and supposed to be there.

 

If you cant fit the splices in the box with standard wirenuts for some reason, you likely have a bigger problem. What you intend to use is not going to make any significant difference if you just use a standard wirenut.

You'll need to do some carpentry and replace the box with a larger one.

What type of box is this? How many wires are in it and what gauge?

It sounds like you have a small switch box or a device box. Do you have full access to the opening of the box? If there is something partially covering the opening, whether its ceiling or facia as you mention then that ceiling and facia needs to be cut. Safe wiring comes before aesthetics.

Your best course of action would be to call a licensed electrician to tackle all these issues.

EDIT: I re-read your post and I see your talking about #6 feeders and not standard branch circuit wiring. Someone will need to take care when splicing such large wire. Call a professional.

 

While those connectors will work, your description of the junction box leads me to believe it isn't big enough for these connectors to be used.