Electrician Crossed 220vac and 120vac - need assistance verifying the damage

DEAD THREAD - TO BE DELETED. BRITISH SITE.
My Electrician made a mistake and I need assistance verifying the damage.
Environment:
A. Kitchen and Garage Remodel.
B. Range being changed from electric to gas.
C. Circuit Breaker 7/8 220vac Oven.
D. Circuit Breaker 31 120vac GFCI many outlets. (master bath, outdoor sockets,..)
E. Circuit Breaker 33/34 220vac to Pool Equip SubPanel.
Objectives and Request:
1. Electric Oven 220vac Circuit (breaker 7/8) no longer needed.
2. Two Garage GFCI 120vac Sockets (on breaker 31) were tripping too often with power tools(table saw etc), also since it is shared with 3 Master Bath sockets, and 2 exterior porch sockets. Request to have 2 garage sockets get own circuit.
Wiring:
3. Picture 1 - new attic Junction Box with original white 10 gauge 220vac coming in, yellow 12 gauge 220vac going out. (mistake 1, should be 10-2)
4. Picture 2 - Existing Garage Socket Junction Box - 3 wires coming in, 4 twisted together. (mistake 2, did not disconnect 31 wires)
5. Picture 3 - Garage Socket Junction Box - 3 wires coming in, 4 twisted together. (mistake 2, did not disconnect 31 wires)
Events and Problems:
a. Circuit Breaker 7/8 off. Everything fine.
b. Action: Circuit Breaker 7/8 turned on.
c. Result 1: Circuit 31 flips off.
d. Result 2: Pool Pump and hot tub not working. (in a subpanel off 33/34)
e. Examine 1: Subpanel breaker for Hot Tub had flipped off. Turned on, all well.
f. Examine 2: Pool Pump dead, verified 220vac (also verified each pole separate for 120 good)
g. With 31/32 off, 7/8 on, I have 120vac in Master Bath sockets and Garage Sockets.
h. With 31/32 on, 7/8 off I have 120vac in Master Bath sockets and Garage Sockets.

Solution: Disconnect existing 31 wire coming into one of the garage sockets, and somehow verify only getting on pole/leg?

Question #1: How to get only 1 pole/leg for that socket? (I would first un-nut all wires at garage sockets, kill 31. 7/8 on. ID 7/8 coming to sockets. Then?)

Question #2: How come I only get 120vac at sockets with 7/8 on, 31 off?

Big Big Key Question #3: Did electrician blow my pool pump? If so, how? He claims impossible.

This is a UK website and our electrical systems are very different to yours.

Try one nearer home.

You need another electrician to prepare an inspection and report.

If you do any do-it-yourself fiddling to try and identify or resolve the problems then the original electrician has a defence that you caused or worsened the problems and he's not liable.

(Yes, of course, the guy is crap. Yes, I need to hire a better professional someone else. Yes, I cannot touch or change anything until it is resolved or the evidence is gone. But I feel that simply opening the junction boxes to look is safe (legally). Yes, wires are fine and other things are fine, I will check. Yes, pool pump needs replaced $1,600. For now, lets forget about wire sizes and amps per breaker.)

THE key point That I wish several to confirm here:
If Neutral ANYWHERE has been compromised by attaching a hot, then ALL GFCI circuits (which depend on a clean Neutral) are no longer isolated and CAN interact through the panel. Only GFCI circuits?
Thus attaching A Hot and A Hot from a 240vac circuit (7/8) to a Neutral and a Hot from a 120vac GFCI circuit (31) in a socket box COULD AND WOULD cause issues on a separate 240vac GFCI circuit (33/34) for a pool pump. And could ruin the pump.
True? Seeking a few people to confirm.
Thank you all.
Walt

"If Neutral ANYWHERE has been compromised by attaching a hot,"

In our country you can't do that. It would be a short-circuit resulting in the immediate tripping of the breaker, failing that the main fuse, failing that a spectacular flare and possibly a house fire.

I told your, our electrical system is quite different. We don't have split phase, and we don't have two voltages in a house.

DEAD THREAD - TO BE DELETED. BRITISH SITE.

JohnD said:

This is a UK website and our electrical systems are very different to yours.

Try one nearer home.

Click to expand...

So what exactly is the point of having an "Electrics outside the U.K." section if anyone asking something within it is only going to be told that this is a U.K. site and to go elsewhere?

I don't know if the OP will be back to see this, however.....

As I understand it, what was supposed to have happened was that two of the existing garage receptacles on a shared GFCI circuit with many others were to have been moved onto a new circuit, which was to be fed in part using a now-spare cable which was formerly feeding an electric oven.

It's not clear from the original description, but presumably the oven circuit was a straight 2-wire 240V 30A circuit as it was wired with 10-2 cable. There would be nothing wrong with using this cable for a new 120V 15 or 20A circuit (extended with 14-2 or 12-2 minimum respectively) to regular 120V receptacles, so long as the original 30A double-pole breaker were replaced with the appropriate single-pole 15 or 20A type, and the white wire of the 10-2 moved over to the neutral bus.

Whatever existing circuit was running to the two outlets concerned would need to be disconnected from them. Depending upon the physical arrangement of cables, that might mean simply disconnecting at some other point, or leaving the circuit running through the existing boxes but isolated from the receptacles and the new wiring.

It sounds as though this "electrician" has run in new wiring but somehow tied everything together with the existing circuit. And it so happens that the original circuit to those receptacles and the new one are on opposite poles of the supply, which in some ways was a good thing, otherwise you might never have realized that he had two breakers paralleled via the cross-connection and would have been left with insufficient overcurrent protection on the wiring.

As for the pool pump, the issue would be whether or not he disturbed any of the wiring on the feeder to the pool sub-panel. If he did not, then the cross-connection between the other circuits wouldn't have had any effect. If he'd lifted the neutral from the pool panel sub-feeder and connected it to a hot line by mistake, then most certainly it could burn out things, since some 120V branch circuits on the sub-panel would then be receiving 240V. Or indeed if he'd just lifted it from the neutral and applied power to the sub-feeder it could cause excess voltage on one side of the panel, depending upon the loads connected at the time.

There's absolutely no reason why he should have done anything with the sub-feeder wirng to carry out the other task, but given the mess he's obviously made of the job, who knows what he might have done?

PBC_1966 said:

JohnD said:

This is a UK website and our electrical systems are very different to yours.

Try one nearer home.

Click to expand...

So what exactly is the point of having an "Electrics outside the U.K." section if anyone asking something within it is only going to be told that this is a U.K. site and to go elsewhere?

Click to expand...

Because quite a lot of British people (compared to USA) travel abroad, have holiday homes abroad, or even move abroad. However this is usually within Western Europe where electrical systems are fairly similar and wiring standards are often harmonised.

If that is what the owners of the board intend, then perhaps it might be a good idea to change the area description:

Electrics Outside of the UK
Questions, comments and enquiries related to household electrics outside of the UK from around the world.

Click to expand...

Electrics Outside of the UK

Click to expand...

Which bit of that do you think should be changed, and why?

Questions, comments and enquiries related to household electrics outside of the UK

Click to expand...

Ditto.

from around the world.

Click to expand...

Ditto.

ban-all-sheds said:

Electrics Outside of the UK

Click to expand...

Which bit of that do you think should be changed, and why?

Click to expand...

Nothing.

Questions, comments and enquiries related to household electrics outside of the UK

Click to expand...

Ditto.

Click to expand...

And nothing.

from around the world.

Click to expand...

Ditto.

Click to expand...

In relation to this comment:

OwainDIYer said:

Because quite a lot of British people (compared to USA) travel abroad, have holiday homes abroad, or even move abroad. However this is usually within Western Europe where electrical systems are fairly similar and wiring standards are often harmonised.

Click to expand...

If that was the aim of this area, it would seem more sensible to say "from around Western Europe" or "for Brits living in Europe."

"Questions, comments and enquiries related to household electrics outside of the UK from around the world" does rather suggest anywhere outside the U.K., don't you think?

on the other hand, is it wrong to suggest to an American who may not know that .com is international, and who may not understand the RoW is different, that he might do better asking nearer home?

See also "Appliances" 10 Jan 2009

JohnD said:

on the other hand, is it wrong to suggest to an American who may not know that .com is international, and who may not understand the RoW is different, that he might do better asking nearer home?

Click to expand...

No, but then what's the point of encouraging the posting of such queries by suggesting that the area is for enquiries from the whole world? It seems like it's just a waste of time for everybody.

The poster does not say where he lives. I know Algeria also has a 110 volt three phase supply system but wire colours were same as Europe. Jumping in both feet to try and help can cause problems when mistakes are made as to country involved.

However Brits abroad often can't use local forums as they write in English and country they are in does not use English on their local forums. So we try to help. But for Australia. New Zealand, and USA they write using English so there is no point in using a British forum.

To me for a post on outside UK site at least the poster should state the country they are in. And until that is done all we should as is where are you. As it is so easy to make errors.

It looks as though the poster's account has been deleted now, but for what it's worth, at the time of the initial replies it did show his country as being U.S.A., and everything else in his post in consistent with that.