Under counter fridge earthing - Quick sanity check

[SparkyChick]

Morning all,

Did an EICR a couple of weeks ago and one of the things I commented on was the fact that the metal work of an undercounter fridge (the door hinge/skin mounting arrangements) did not have any continuity to the CPC of the circuit supplying it.

I can find no indication of it being a Class II appliance and this is backed up by the user manual I was able to find on-line which explicitly states the appliance should be earthed.

Today I'm doing the remedial work and obviously I'm going to need to investigate this lack of CPC continuity if it's 'a thing'

My sanity check question is am I correct in my assertion there should be continuity between the supply circuit CPC and the metal work that is accessible when the door is opened? I can find no reason in my head why that shouldn't be the case, but you guys may know otherwise.

Thanks

 

[telectrix]

check continuity from earth terminal to the metal chassis where the compressor etc.is mounted.

 

[SparkyChick]

Thanks Tel,

I was thinking about whether the main bulk of the fridge was insulated from main work horse courtesy of the typical rubber anti-vibration mounts. My concern came from the very obvious metallic links that exist in the form of the refrigeration circuit, so I was struggling to justify the lack of continuity to the door hinges in my own head.

Guess I'll be taking a mirror to see up the back of it... fingers crossed my arms are long enough to reach Think I'll leave this job till last as the floor under them is filthy and sticky... ewww

 

[telectrix]

pull the bugger out.

 

[bigspark17]

I would class this as an appliance and leave that to the isitee. Eicr radial/dedicated circuits tested to isolation points only & test to isolator imo.

 

[telectrix]

but she's probably doing isitee as part of the deal.

 

[bigspark17]

That would make sende then

 

[Paul228]

Rather than use a mirror, simply use your mobile to take pics. Then you can zoom into the pics to see an issues.

 

[Specialist]

Should be a Class 1 appliance, check continuity from the earth pin on the plug to one of the hinges. Where it attaches to the main body of the fridge, if you do it on the door itself then it can show no continuity. Most hinges have nylon inserts as bearing surfaces.

 

[Pat H]

Its more than possible that the compressor assembly and all the related electronics are isolated from the rest of the metal work.
As already posted I'd check continuity to the compressor and surrounding metal work.

 

[Marvo]

With a normal underbar fridge the refrigeration components such as the compressor, its associated pipework, the condenser and evaporator coil etc would by securely physically and electrically connected to the chassis of the fridge. The refrigeration pipework is usually continuous copper and various parts of the refrigeration system are in firm mechanical contact with the chassis of the fridge.

The doors often have plastic hinges but these would not usually be liable to introduce a potential.

 

[Octopus]

Maybe you need to check the ZS of the plug it's in first.....

 

[Pat H]

Maybe you need to check the ZS of the plug it's in first.....

Or maybe the socket rather than the plug....

 

[SparkyChick]

Unfortunately the designers of said kitchen weren't really considering our needs The socket to which they are connected is behind them (the fridge and freezer), they are securely fixed into place and the customer didn't want me to dismantle his kitchen.

There is no earth continuity to the door hinge (fridge body portion) or the fixing bolts for that, however there is earth continuity between the RFC that supplies the SFCU for them and the chasis members on the bottom at the rear of the units (accessible with the kickboards removed), so I'm happy.

I checked all four hinge brackets and got nothing, checked heat exchanger in the fridge and got nothing (and checked between the various exposed metal items and got no continuity between any of them), but the chasis member at the rear is connected to the RFC that supplies it.

And no, I'm not providing a ISITEE service to them and have made them aware of their obligations in that respect (a note to that effect will be going along with my final report and accompanying minor works certs for the fixes I've had to do on the lighting circuits - choc block ceiling rose replacements).

Thanks chaps

 

[The Ghost]

Was that with a wander lead. And dare I ask...what code if any did you give it?

 

[westward10]

None if they were plugged in.

 

[SparkyChick]

Yes, it was with a wander lead from the ring final circuit (which I had already established had a perfectly acceptable CPC connection) and from the MET in the consumer unit.

Originally I was going to code it C2 as it has the potential for danger if there was a lack of earth continuity between the metal fittings and other exposed metal accessible to users. But there is absolutely no continuity between any of the exposed metalwork, nothing. When testing this with the wander lead I was concerned that the earth was missing completely and not being able to see the connections I was concerned.

However, since there is earth continuity to the chassis members which appear to provide strength to the appliance at the rear (I had to lie on the floor and reach under them to access with the kick boards removed), I'm happy the appliance is earthed as required by the manufacturer.

I did try continuity tests between the various exposed metal elements to try and establish whether it was just a poor connection on one or two, but as I say there is absolutely no continuity between them, not even to the skin of the appliance, so for me it's no code. All the controls are plastic, the only electrical component that is remotely accessible is the lamp in the fridge and that requires a tool to access it.

 

[bigspark17]

so if you weren't doing an isitee why were you checking earth continuity on a fridge plugged into a ring final? did you go around checking earth continuity on all portable appliance? did you price this per circuit, not questioning your very thourough technique atall btw

 

[SparkyChick]

Was going round anyway checking CPC continuity to metal fittings (which turned up a couple of issues like missing earth to a metal light fitting that simply had a bayonet cap which plugged into the existing pendant and a chocblock ceiling rose replacement in the lounge which robbed the metal switch plate of it's earth).

So when I hit the kitchen I checked the appliances where I couldn't access their final terminations. The hob, oven, boiler (checked that because it's connected using a plug and just wanted to make sure) and the under counter fridge and freezer.

 

[davesparks]

I don't think I've ever had a fridge with earth continuity to the hinges when I've Been doing portable appliance tests.

If you are really concerned then IR test the hinges to earth.

Remember that bonding metal parts which don't require it can make things more dangerous.