RCD Tripping - Advice Needed

[jakeevans]

Hi Everyone,

So basically like a few other people, I really need some advice from some professional electricians and found this forum so I really hope someone out there can help.

Basically we had a hot tub installed back in June 2017, everything was running fine, till we went for a holiday in December 2017 so turned it off. When we came back, filled it back up and turned in on. Ever since that month 2 weeks after, our RCD seems to be tripping every now and again very randomly.

We called in a electrician who stated "I told you your old consumer unit may not supply enough power and it's given up". At that point, other devices in the home like our speakers were tripping the RCD instantly but yet at the neighbours house when tested, didn't.

So we went ahead with his advice of changing the whole consumer unit (he said it was worthwhile as the new 17th Regs came out and wouldn't hurt as it was 10 years old+)

So now once he fitted the new consumer unit, turned everything back on.. and voila all sorted. However, a week later, the new consumer unit RCD is tripping again! We tried to do our own fault finding and found that turning of the hot tub stopped the tripping. Called him and he said he doubts its the hot tub, so we called him out to come and see. In front of me, he showed and said the hot tub is fine, and is showing the correct voltage/amps at the tub. He said the next step is to do fault finding but its going to be running into the hundreds £££ and said the next time it happens try and unplug everything and plug one by one in to see if we can work out what's causing the RCD to trip, otherwise he's going to have to come and rampage through all the devices/sockets and made out it's a massive job.

So he left, and long and behold it tripped later on, so I did what he recommended, unplugged all our plugs from the sockets, and plugged them one by one..RCD didn't trip.

So having all circuits on again, the RCD seems to be tripping again and again daily. For example a 2 days ago, it tripped twice, just yesterday it tripped four times.

I still have a serious hunch its the hot tub, so yesterday night, turned it off at the consumer unit, and touch wood, it hasn't tripped up to now.

My question is to the electricians out there, is the hot tub causing the RCD to trip? The electrician said it's not the hot tub, yet when I turn the circuit off to the hot tub it hasn't tripped the RCD (as of yet).

I was also doing a bit of research about this earth leakage topic, and I'm not sure if I'm right, but am I right in thinking that if there is enough earth leakage on all the circuits it would trip the RCD? Reason being is that if I go with the theory its the hot tub, I'm guessing when the blowers automatically come on, or the pump/heater comes on, it's possibly sending a spike over the RCD limit?

The reason I came up with this theory is that we do run a small business from home, we have about 3 pc's, 8 monitors, 2 big laser printers, two freezers, three fridges..etc do you think that the earth leakage of all these are adding up, and the hot tub is the cherry on the top that's causing the it to trip randomly?

Just as background information, he's put a single RCD that's connected to our Kitchen Sockets, Upstairs Sockets, Downstairs Sockets, Shower, Utility Room Sockets and the hot tub. He has then used RCBO's on each lighting circuit.

Any help would be gratefully appreciated.

Kind Regards,
Jake

 

[ipf]

This is getting a bit daft.
It's a basic mistake for a qualified electrician to design such a layout with RCBO's, MCB's and RCD's. It's devoid of competence. Makes you think!

 

[sparksburnout]

No................ but after 2 attempts and no reasonable response from the OP one does wonder if it actually exists ....................... and then the OP gets arsy .....................

Edit : I see you are in Notts - you didn't do the install!

Shush don't tell em.

 

[UNG]

This is getting a bit daft.
It's a basic mistake for a qualified electrician to design such a layout with RCBO's, MCB's and RCD's. It's devoid of competence. Makes you think!

The OP made the comment that he checked that the operative carrying out the work was part p qualified which suggests he was using a Domestic installer and not an Electrician.
Bad installation design comes from a lack of proper training and on the job experience and as time passes rather than increasing the skills needed the profit before skills organisations are diluting the skill set needed to provide problem free installations.
As the world get's more technologically advanced the solution to installing it and even the basics appears to be a reduction in the level of training where it is at the bare bones of competence

 

[ipf]

The OP made the comment that he checked that the operative carrying out the work was part p qualified which suggests he was using a Domestic installer and not an Electrician.
Bad installation design comes from a lack of proper training and on the job experience and as time passes rather than increasing the skills needed the profit before skills organisations are diluting the skill set needed to provide problem free installations.
As the world get's more technologically advanced the solution to installing it and even the basics appears to be a reduction in the level of training where it is at the bare bones of competence

Maybe I should have said 'for a domestic installer' rather than a 'qualified electrician'. It is pretty basic after all....then again, I suppose they are 'taught', these days, that, in most cases, all domestic circuits should be rcd protected, so, if some aren't, does it matter which?

 

[Gasinspect]

This is copied from an article NAPIT did on requirements for replacing consumer units:
Requirements of BS 7671

Replacing a consumer unit is classed as making an alteration and falls into the category of new work. This must be designed, erected and verified in accordance with BS 7671 as required by Regulation 110.1.2 (vi) and the safety of the existing installation must not be impaired, as stated in Regulation 610.4.

Regulation 132.16 states the requirements of additions and alterations. This means existing equipment must be adequate for the alteration. The earthing and bonding must also be adequate for the installation.

The design will also need to consider Regulation 415.1 for additional protection by 30mA RCD and consideration of how to protect against unwanted tripping of the RCD(s) will be needed to comply with the requirements of Section 314, Division of Installation.

Account must also be taken of the manufacturer’s instructions, as required by Regulations 134.1.1 and 510.3.

On completion, identification notices in accordance with Section 514 will need to be fitted and an EIC must be issued in accordance with the requirements of Sections 631 and 632, as stated in Regulation 631.1. Finally, the work must be notified.

Industry best practice

The customer should be encouraged to have an Electrical Installation Condition Report (EICR) carried out before replacing the CU. This will help the contractor to establish that the requirements of Regulation 132.16 have been met to allow the new CU installation to take place. Suitability of the existing earthing and bonding arrangements will be confirmed, as well as the suitability of the DNO’s equipment and meter tails, including polarity of the incoming supply.