Garage Consumer unit

[Taylortwocities]

Ok

So, does the house MCB trip if you turn off the MCB for the lights in the garage?

Then
does the house MCB trip if you turn off the MCB for the sockets in the garage?

That should narrow it down to sockets or lights.
Your problem could be the cable run to the garage.

Why don't you get your professional electrician to sort this out. It is, after all, his problem. If he is truly a professional he will want to sort it out.

 

[ban-all-sheds]

He tested all house circuits but not the garage ones

The garage ones are supplied from the new CU he installed - he should have tested them. At the very least he should have tested the cable supplying the garage CU.

 

[RF Lighting]

Could it be inrush current from the compressor that is taking out a B type breaker?

It doesn't take much to trip a B 16.

 

[blightfoot66]

Could it be inrush current from the compressor that is taking out a B type breaker?

It doesn't take much to trip a B 16.

If that is the case, would I be able to increase the size of the mcb in the house consumer unit that is powering the garage??

 

[ban-all-sheds]

• //www.diynot.com/forums/viewtopic.php?p=81696#81696
• http://www.tlc-direct.co.uk/Book/4.3.1.htm
• http://web.archive.org/web/20080213151445/http://www.kevinboone.com/cableselection_web.pdf
• http://www.tlc-direct.co.uk/Technical/Charts/VoltageDrop.html
  

 

[Monkeh]

Could it be inrush current from the compressor that is taking out a B type breaker?

It doesn't take much to trip a B 16.

If that is the case, would I be able to increase the size of the mcb in the house consumer unit that is powering the garage??

I would advise you to figure out if that's the case before committing to anything. Please, test and find out what trips it. It's not difficult.