Newb with weak 15A circuit

[Firm]

Hi everyone, I am a long time lurker finally turned poster, looking for some help with the circuit in my garage.

I have a typical subdivision home built in 1989. It has a single 15A circuit servicing the garage. Originally there was only 1 outlet and a light in the garage. I added 3 additional outlets to the circuit (simple series wiring from the existing light).

Now, I have intermittent issues with the circuit breaker tripping while using my compressor or newly installed 4-post lift (with 15A 110V motor). When I use these I make sure I have all other loads off and I still get frequent tripping of the breaker.

If I run an extension cord to a different circuit (inside the house) I can run those items no problem.

So my first question is; is there something going on with my 15A garage circuit that's causing it to trip prematurely? Maybe the breaker itself is going bad?

Next, assuming there isn't anything wrong with the existing circuit, rather it's just overloading, whats the right solution here? I *think* the right thing to do would be to run a new 20A circuit from my panel in the basement to the garage so I can have one dedicated outlet from which to run my lift or compressor. Am I right?

My electrical knowledge is pretty mediocre, I've done some basic stuff (like adding or moving outlets) and I've wired our 240V GFCI Hottub circuit, but I had a little help from my FIL on that one. So any help or advice on what to do here is greatly appreciated.

 

[zmaxmotorsports]

Id start by looking for loose connections in the panel,or back stabbed outlets.

 

[Firm]

No back stabbed outlets, but I will check the connections in the panel for tightness. Good call.

 

[Dick in Wisconsin]

I think Zmax is right. I presume that the lift and compressor are down stream from the light.

How did you do the "series" wiring? Did you pig tail each outlet? or did you buy cheap "contractor" outlets at a big box and back stab them? I've learned on GJF that back stabbing often results in problems with poor connections. The sparkies often recommend pig tailing or using good quality outlets that support back wiring rather back stabbing.

Is the garage circuit on a GFCI? Code in 1989 might have required that for a garage. Is the garage circuit on its own circuit or an extension of a bathroom GFCI circuit? Try swapping out the GFCI outlet for a new, good quality GFCI outlet. I've also learned on the GJF that GFCI and GFI outlets can "go soft" over time and trip. I've replaced two like that in our house built in 1994.

Did the instructions for the lift indicate its OK to install on 15amp circuit? I've also come to learn on the GJF that we shouldn't expect to have a load on the circuit that more than 80% of the circuit capacity (on a 15amp circuit that would be a 12amp load).

I would have probably run separate 20amp circuits from the panel for the lift and the compressor. Trying to run the lift and the compressor on the "garage" 15amp circuit might not meet code ... especially if you have anything running on that circuit at the same time.

Keep us posted.

 

[G_P]

Running a 15a rated motor on a 15a breaker is going to cause a lot of trips. That circuit should be 20a.

your best bet is to get an amp clamp and put it on the wire coming out of the breaker, then have someone flip on the compressor and see what the meter says, then do the same with the lift. I bet you are drawing more than 15a on that circuit especially when the compressor starts on anything but an empty tank or when the lift has a strain put on it.

The circuit in the house you are running the extension cord from is probably on a 20a breaker and thats why nothing trips then.

 

[James-W]

Would it be practical for you to run a line from the main breaker panel to the garage so you can put in a sub-panel and then run several different circuits off the sub-panel?

 

[Firm]

Thanks for the great advice thus far.

I'll answer some of the questions here:

-The 'series' wiring was done using decent quality outlets and was "back wired" (using the screws on the side of the outlets). They were NOT back stabbed. The light is pigtailed.

-The garage is not on a GFCI circuit (in Canada this house pre-dates that code)

-Lift instructions do say that a 15A circuit is fine, but I agree that running a 15A motor on a 15A circuit is not ideal.

I think my course of action will be to leave the existing 15A circuit as is (aside from double checking the connections at the panel) and run a seperate 20A circuit from the main panel. A subpanel would probably be ideal here, but I think it's beyond my abilities and would be overkill for what I do in the garage. There wouldn't really be a scenerio where I would be running the lift and compressor at the same time, so I figure with one 20A outlet I'll be able to run whichever one I need.

So the next question is; does anyone have a good video or guide to running a new 20A circuit? I have a pretty good idea of what to do (I assume it's very similar to the 240V we did for the hottub), but it would be nice to have something to follow.

 

[justsam]

Is the garage attached or detached? Not sure of code in Canada but in US, if garage is detached, only one circuit can be run which pretty much forces a subpanel.

Not an issue if attached, run as many circuits as you like. Should be easy enough to install an additional 20 Amp circuit if you have an empty breaker slot.

 

[Firm]

Garage is attached. I don't have an empty slot in the panel right now, but it should be easy enough to free up a spot by installing a tandem breaker to consolidate some existing circuit to make space for the new 20A.

 

[WanderingSol07]

I would think if you have 12ga wire running on the circuit now, you can swap out the 15A breaker with a 20A. Even though your lift motor is rated at 15A, I doubt it pulls that much when running, that is probably the stall current rating.

I suggest you pull all but the last duplex out in the circuit, use wire nuts to connect the wires where you have taken out the outlets. Then see how the circuit handles the load.

Got a Kill-A-Watt meter you can use to see what the load is really like?

 

[Banjorear]

Would it be practical for you to run a line from the main breaker panel to the garage so you can put in a sub-panel and then run several different circuits off the sub-panel?

I just did this over the weekend. I was lucky in that I had an open 50A circuit due to the removal of a hot tub.

I was having the same issues prior to installing the new sub panel. Not sure what you can do with a full panel, but I would ask an electrician to see what can be done.

Thank goodness my dad is an electrician and helped me with the work. I forgot how much work this was going to be. I did an entirely separate service in my pervious garage about 10 years ago.

 

[ripperd]

Garage is attached. I don't have an empty slot in the panel right now, but it should be easy enough to free up a spot by installing a tandem breaker to consolidate some existing circuit to make space for the new 20A.

Tandem breakers are only allowed in certain boxes. Also, just because it fits, doesn't mean its allowed.

http://www.ashireporter.org/HomeInspection/Articles/Inspecting-Tandem-Circuit-Breakers/2047

 

[Firm]

Tandem breakers are only allowed in certain boxes. Also, just because it fits, doesn't mean its allowed.

http://www.ashireporter.org/HomeInspection/Articles/Inspecting-Tandem-Circuit-Breakers/2047

Great link, thanks! I'll have to check out my panel later and confirm whether or not it's allowed.

 

[ishiboo]

If the lift recommends 15A circuit, and has nothing else on it and trips, make sure all connections are okay and no other significant loads are on. Then replace the breaker or swap it with another (still 15A unless the circuit is all 12ga) and see what happens.

 

[Firm]

If I plug the lift into the first outlet in the series (which is actually before the light) would that eliminate the effects of any potentially loose connections? Or does a crappy connection somewhere downstream affect the integrity of the entire circuit?

 

[teamextreme]

Downstream won't affect rest of circuit. But I doubt a loose connection would cause your breaker tripping problem. If the connection is bad enough to cause a breaker to trip (which I don't think I've ever seen) you would have seen other symptoms of flickering lights, unstable power, etc.

You've got one of 2 things going on. Either the breaker is weak, which is very rare, or there's additional load on the circuit that you're not aware of that when added to the lift current, trips the breaker (my money is on this).

As some others have said, if you have an amp-clamp you can test the circuit for current draw without the lift on at the breaker panel. You only mentioned that the motor is 15 amp. Is that the actual FLA on the nameplate? If so, it shouldn't be on a 15 amp circuit anyway and any additional load will surely trip the breaker. In fact, even with nothing else on, it wouldn't surprise me that it would trip quite frequently at startup. My 15 amp FLA chop saw would trip a 20 amp breaker about half the time on startup.

 

[theoldwizard1]

First, all this info applies to US codes !

Second, if you are going to do the work, spend a bit more and "do it right". Install a subpanel in the garage. Use 8-3 NM-B and you should be good for 60A.

Unless you have a really old breaker panel, if the manufacturer makes a tandem breaker for it and you put it in the correct slot (not all slot accept tandems) you are good to go.

The cost difference between pulling a 12-2 NM-B and installing a 20A outlet and pulling 8-3 NM-B, installing a 6 slot panel and all of the appropriate breakers is less than $200. If you hire it out, the cost difference should be less than $300

 

[Firm]

Wow, lots of great advice here

Firstly, the circuit is mostly 14/2, so the idea of swapping to a 20A breaker is not an option.

I am thinking Teamextreme might be onto something with the "hidden" load idea, I am going to try to get my hands on an amp clamp so I can test. I am also going to double check the specs on the lift, I know I saw 15A written somewhere on the tag, but I'll double check exactly what it says and report back.

I would prefer to avoid running a sub panel if I can, just for the sake of keeping it simple as I am not too well versed in this stuff. Running an extra circuit is something I am pretty comfortable doing, and while a sub panel might not be much more difficult, I just dont see the need to complicate things at this point.

 

[maynard9089]

How far is the panel from the garage? My panel to my garage is over 60'. The resistance created on longer runs will require heavier wire and larger breakers.

 

[Firm]

Not far, Maybe 20ft. The panel is in the basement, but along a wall that's shared with the garage.

 

[Dick in Wisconsin]

I would prefer to avoid running a sub panel if I can, just for the sake of keeping it simple as I am not too well versed in this stuff.

Why? A sub-panel will go a long ways to solving your current problem and give you added flexibility down the road. Find a good electrician to help you on the weekend as a side job. You do all the time consuming work and let him wire the panels.

 

[Firm]

I generally try to avoid hiring contractors, and i was forced to use two of them within the last 6 months (1 roof repair, 1 garage door conversion) so I've had my fill of contractor B.S for awhile.

 

[Firm]

While I haven't had much time to investigate this too much yet; I did make a couple observations today.

Firstly, the existing 15A circuit had no trouble running my 1000W (8.5A-ish?) space heater for a couple hours this evening. Also had my exterior Christmas lights, radio, and 3 bulbs in the garage running off of it along with the heater. So maybe the circuit isn't as weak as I'd thought.

Also, a couple people asked about the actual Amp rating on the lift, I only see one rating here (15A), I am not sure if that's maximum or a continuous rating? But I took a photo of the actual sticker because maybe there's something I am missing?