electricians advice

i've just been quoted (well, estimated) for supply and fit of a split load consumer unit in a 3-bed semi. 9 circuits to connect. £200ish. Sounds a bit low in my opinion. Sparky lives just round the corner, never used him before, dont know him from adam. Said he will be here on friday at 5pm. I assume he will be pulling the supply fuse himself, since he didn't mention contacting the DNO. I am a little worried that this price wont include testing the existing circuits. Any comments from sparks welcome.

Also, asked his advice on how much work i could do in wiring my new shed up, he said if it is wired up when he comes to connect it, thats not a problem. So am i legally allowed to wire the shed up myself to the shed consumer unit, and just have him make the connection to the house? Again slightly concerned here too, but i know i have the skill to do the work within the shed myself. Can he test and certify work i have done?

My one question to you is, if you are concerned about this guy, why is he coming round on Friday???

He should at the very least issue a PIR (changing a CU is NOT minor works).

Can he test and certify? Well, others are most reluctant to do so.

Connections to a shed are notifiable, in terms of Part P.

Is this guy Part P certified?

securespark said:

My one question to you is, if you are concerned about this guy, why is he coming round on Friday???

He should at the very least issue a PIR (changing a CU is NOT minor works).

Can he test and certify? Well, others are most reluctant to do so.

Connections to a shed are notifiable, in terms of Part P.

Is this guy Part P certified?

Click to expand...

In a Nutshell really....

PIR will be about £150 - £200 so doesn't leave much for parts.
Is he registered?
Does he possess the test eqiupment?
Is he qualified?

If he's that cheap is he even insured? he should have £2mill indemnity.

thought we wernt allowed to discuss prices/costs on here???

screwi, shhhh! he is a registered installer with niceic and part p registered as far as i know (i checked the website). Could he do the work this cheaply because we are local? Dont forget we are in Doncaster, not London .

Connections TO a shed are notifiable, in terms of Part P.

Click to expand...

But are connections IN a shed notifiable? (connecting ring finals and lights to the CU etc)

According to the ODPM, if a circuit cable with quote, "suitable" connection points exists, then adding to the circuit is not notifiable.

ok, he's been now, we now have a shiny new Hager consumer unit, and tests have been carried out after 2.5 hours and £200. Pretty good value i think! However . . .



A few things concern me. As you can see, one of the MCBs has been labelled "fridge/freezer" however, the fridge freezer is plugged into the kitchen ring main, and it appears this MCB in fact controls the shed radial (16A) which i would rather have on the RCD protected side for now, until the new shed is wired up.

Initially, the upstairs/dining room socket ring was wired on the RCD side, but the RCD kept tripping, even when everything was unplugged, so he moved it to the other side.

The circuit simply labelled "sockets" in fact is the living room radial. If he didnt have labels for these circuits why didnt he just write them on?

The MCB that is off is spare, i suspect where the upstairs sockets were connected. Very nice of him to leave it there instead of another hole.

In order to connect the new CU, a lot of crimping and extending was nessecary (in new core colours). He didn't put a sticker anywhere to warn of new core colours.

The shower, which in fact takes 45.6 amps, has been connected to a 40A MCB. He didn't even query us as to what rating it was.

He left paperwork with us, but i am not sure what some of the items listed mean. Maybe someone on here can expain what it all means!
0.5 x I delta = no trip
1 (or l) x I delta = 117.3 + 36.9 mS
s (or 5?) x I delta = 30.7 + 33.9mS
Ramp (?) = 25mA
Prospective fault current at consumer units = .81kA

He used a Megger on the cooker socket. What exactly does this do?

Ye gods.

crafty1289 said:

Pretty good value i think!

As you can see, one of the MCBs has been labelled "fridge/freezer" however, the fridge freezer is plugged into the kitchen ring main, and it appears this MCB in fact controls the shed radial (16A) which i would rather have on the RCD protected side for now, until the new shed is wired up.

Initially, the upstairs/dining room socket ring was wired on the RCD side, but the RCD kept tripping, even when everything was unplugged, so he moved it to the other side.

The circuit simply labelled "sockets" in fact is the living room radial. If he didnt have labels for these circuits why didnt he just write them on?

The MCB that is off is spare, i suspect where the upstairs sockets were connected. Very nice of him to leave it there instead of another hole.

In order to connect the new CU, a lot of crimping and extending was nessecary (in new core colours). He didn't put a sticker anywhere to warn of new core colours.

The shower, which in fact takes 45.6 amps, has been connected to a 40A MCB. He didn't even query us as to what rating it was.

Click to expand...

Plus basketweave cables, drunken and incorrect labelling, a missing blank on the CU...

You were worried he was too cheap, and now you've got this. Does the phrase "you get what you pay for" mean anything?

crafty1289 said:

He left paperwork with us, but i am not sure what some of the items listed mean. Maybe someone on here can expain what it all means!
0.5 x I delta = no trip
1 (or l) x I delta = 117.3 + 36.9 mS
s (or 5?) x I delta = 30.7 + 33.9mS
Ramp (?) = 25mA
Prospective fault current at consumer units = .81kA

He used a Megger on the cooker socket. What exactly does this do?

Click to expand...

Assuming a 30mA RCD for supplementary protection;

0.5 x I delta is the RCD trip test at half trip current, RCD shouldn't trip.
1 x delta is the trip test at trip current, RCD (BS4293) / (BS7288 socket outlet) must trip within 200mS, RCCB (BS EN 61008) / RCBO(BS EN 61009) within 300mS.
5 x delta is the trip test at 5x trip current and must trip within 40mS.

Ramp is a newish test on some RCD testers which measures the current required to operate the RCD. This is sometimes useful in fault finding a faulty RCD, however is not one of the checks required by BS7671.

PFC is the maximum current under fault condition at the CU. This is important when selecting the correct kA rating of MCB.

A Megger (brand name) is usually reference to an insulation resistance tester. It basically introduces 500v into the circuit and measures the resistance of the cable insulation under voltage condition. 500v is for normal mains wiring, testers may have more than one range for other tasks.

ban, the basketweave cables were there before. This electrician actually tidied them up and fixed them to the wall. And you misquoted me

Pretty good value i think! However . . .

Click to expand...

Anyway, the upstairs sockets dont need to be RCD protected . . .

I can buy a colour warning sticker . . .

and a blank for the spare way . . .

and i forgot, our shower is 9.5Kw (41.3A), but i can buy a 45A MCB and do a straight swap . . .

And the labelling is nothing a bit of tippex cant sort out.

I also spotted this. He has extended the meter tails using this redundant henley block, but it looks a right mess now, and the old neutral tail looks like it is wrapped in cloth why didn't he just re-wire into the meter while he had the fuse out?


Im not worried, if anything goes wrong, he has left his name and adress on the new consumer unit and all over the test sheets.

Well for comparison, I recently did a CU change for someone that had a TT feed, the board will be upgrading to PME in the next 6 Months, but not just yet.

Anyway, I bought a Nive New MEM 12 Way enclosure c/w 100A 300mA 2.5sec Time delayed Type S RCD Main switch and 8 MCBs for the princely sum of £59.62 +VAT (£70.05). I then purchased two 32A 30mA RCBO's and one 40A 30mA RCBO (£67.89+VAT){£79.77} Total).

Materials costs were then £127.51 +VAT (£149.82)

I swapped over the boards and labelled them correctly using a Label Maker. Tested the Installation and completed a PIR.

Total Work Time, 4.5 hours Charge to Client was Materials @ £149.82 + 5 Hours Labour (inc VAT) @ £150.81, so the invoice totalled (Including VAT) £300.63.

Now I could, if not a TT supply have done this slightly cheaper, the board configuration would be different, the two groundfloor socket circuits would still have required RCBO's though as both supply equipemtn that is regularly used in the gardens, and the Shower would still be on the 40A RCBO. It would only be the Main RCD that would get changed for an Isolator, and this would have reduced the cost by about £15 +VAT fro the wholesalers.

So you can see, to have a Job done properly, you need to shell out some money.

I personally think that the standard of work you have recieved falled way below the acceptable minimum standard anyone should expect from any tradesman, and I would be horrified if I saw a spark leave a job in that condition. It certainly implies that the Test Certificate may not be correct, and you should consider contacting the NICEIC, sending them photo's of the work and how it's been left and asking them to step in..you said he is NICEIC registered, so let themn earn their fees.

Are the mcb's new as there looks to be two different styles installed?

This all makes my amateur DIY job look fairly polished...well at least not unreasonable (though some of the purists out there might like to comment).



Seriously though - if anyone can spot anything amiss here I'd like to know....

carefull_bodger the incoming tails look like they are only single insulated but there may not be much you can do about that.

other than that it all looks ok to me but its hard to tell with the covers on