Electrical panel

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Posted by: from Langley
11/7/2019 at 4:45:38 PM

I have 100 amp service to my shop and the mains are tripping with an estimated 60% load.

Can the mains be weak and need replacing?

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Date/Time11/8/2019 at 4:38:41 AM


Other possible causes.

Loose connections (most likly)

Attached equipment overloading one of the two 120 volt phases and therefore the 60% load gets placed all on one phase. The attached load is faulty.

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Jeff from JW Electric in Gananoque
Date/Time11/8/2019 at 7:59:18 AM

It's possible, you could also have a high draw on one of the phases or there could be other issues ie. loose connections.

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Date/Time11/8/2019 at 8:58:22 AM

Load must be calculated and measured properly then check for loose connection .

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Date/Time11/8/2019 at 11:34:07 AM

1. Load could be unevenly distributed onto one line of your 2line single phase system,

2. Main Breaker could be faulty and need of replacement.

3. Have your local electrician ensure that your service is compliant.

4. If you find half your shop is working then the utility supply transformer could be faulty as well.

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Date/Time12/3/2019 at 9:06:38 AM

In addition to what has been posted, what is the distance from the main panel to the garage and what is the size of wire that is being used?

You may have what is called voltage drop and you may think your current is only 60% but oculd be much higher.

A licensed electrical contractor will be able to determine the correct sized cable and / or breaker for your garage. Having said that, I would definitely check for loose connections and faulty breaker first.


J.L. Kuehnl-Cadwell, CD, ME

Master Electrician

Datawise Solutions Inc

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