RCD omission risk assessment

[Elgreko]

They definitely will not be used to supply equipment outside, I will have a look at the sample you guys have posted and will try and learn some new office based skills and make a draft.

 

[Elgreko]

Thanks.

Thank you i will see if I can use this.

 

[loz2754]

It's in an earlier post bit here you go

View attachment 64932

Interesting and useful but not really a risk assessment for justifying omission of RCDs for additional protection.
A risk assessment should identify the hazards, who or what is at risk and from what? And then should identify what has been put in place to minimise the danger presented by such hazards.

 

[Elgreko]

Interesting and useful but not really a risk assessment for justifying omission of RCDs for additional protection.
A risk assessment should identify the hazards, who or what is at risk and from what? And then should identify what has been put in place to minimise the danger presented by such hazards.

This unfortunately is the side of the job I’m trying to learn, I’ve spent my entire working life on the tools and not much time on the paperwork side of things, unfortunately also I have no one to turn to in our office for advice and help, hence why ive posted to the forum. Hoping someone would maybe have a suitable scenario that they have been through themselves.

 

[Lister1987]

Interesting and useful but not really a risk assessment for justifying omission of RCDs for additional protection.
A risk assessment should identify the hazards, who or what is at risk and from what? And then should identify what has been put in place to minimise the danger presented by such hazards.

The format was dictated by city and guilds so I can't really comment beyond that. It justifies omission with appropriate reg numbers, outside of the regs I'm not entirely sure what you'd want on it.

The point of it is we're justifying omission using the regs to present the argument.

 

[loz2754]

The format was dictated by city and guilds so I can't really comment beyond that. It justifies omission with appropriate reg numbers, outside of the regs I'm not entirely sure what you'd want on it.

The point of it is we're justifying omission using the regs to present the argument.

All I see is a somewhat useful list of where RCDs may or may not be required by BS7671, not a justification where it may be desired or necessary to deliberately omit an RCD in a situation where it would normally be required.

 

[Lister1987]

All I see is a somewhat useful list of where RCDs may or may not be required by BS7671, not a justification where it may be desired or necessary to deliberately omit an RCD in a situation where it would normally be required.

By all means take it up with C&G, I merely offered it as an example, you're welcome to expand on it or devise one to share.

 

[Elgreko]

Thank you so much for your help,

 

[loz2754]

Thank you so much for your help,

You're welcome

 

[Teddy Lop]

Interesting and useful but not really a risk assessment for justifying omission of RCDs for additional protection.
A risk assessment should identify the hazards, who or what is at risk and from what? And then should identify what has been put in place to minimise the danger presented by such hazards.

Is there a published document listing the reasons that socket outlets require RCDs?

And if not, why not? How can some regular bozo be expected to carry out a risk assessment permitting him (or her!) to contravene the laws set by a panel of experts without knowing their reasoning?

Perhaps 411.3.3 is insufficient without such qualifying information.

I'm on an EICR for a bakery with a dozen+ 32a 3ph sockets feeding large fixed floor standing machines of various functions and ages. The place runs 20+ hours a day and the 32a seems to be a standard presumably so they can be swapped out promptly. New DB reauired. I struggle to see what dangers are introduced by the bit of wire from each machine terminating in a plug+socket instead of fixed connections. In fact one could observe the enhanced safety of removing the plug as a way of preventing usage of a faulty machine.

 

[timhoward]

I struggle to see what dangers are introduced by the bit of wire from each machine terminating in a plug+socket instead of fixed connections.

Tempting as it is, it never really works to think in terms of the regulations themselves when considering the risks.
Changing all of the sockets and plugs to 63 amp would also comply, as discussed in a similar thread of mine. But neither fixed wiring or changing the sockets affects the safety of the end user if everything is installed correctly, the equipment is in perfect order, and no one does anything silly.

Off the top of my head, the obvious risks are:
-damaged flex impairing electrical safety, especially if the ovens are moved around
-damaged appliance impairing electrical safety
-unsafe equipment being unexpectedly connected to the sockets
-faulty elements causing increasingly significant earth leakage to Class I items increasing the risk of electric shock to operators.

The control measures could be as simple as a sign by each socket saying they aren't to be used for anything else, (or padlocking them), a more regular schedule of In Service (PAT) testing, and a stipulation that if the ovens are moved, they are tested.

You might decide that the above control measures sufficiently mitigate the risks and be willing to put your name to them.
I'm not saying they necessarily do, but that's the thinking process I use for risk assessments. The regulations themselves aren't too relevant!

 

[davesparks]

How can some regular bozo be expected to carry out a risk assessment permitting him (or her!) to contravene the laws set by a panel of experts without knowing their reasoning?

Regular bozos are not expected to carry out such risk assessments, qualified people with knowledge are expected to carry them out.
The risk assessment isn't a permit to contravene regulations, it is a means to assess whether or not RCD protection can be omitted without affecting safety.

I'm on an EICR for a bakery with a dozen+ 32a 3ph sockets feeding large fixed floor standing machines of various functions and ages. The place runs 20+ hours a day and the 32a seems to be a standard presumably so they can be swapped out promptly. New DB reauired.

Why is a new DB required? Surely this is just a recommendation at worst for that scenario?

 

[pc1966]

I'm on an EICR for a bakery with a dozen+ 32a 3ph sockets feeding large fixed floor standing machines of various functions and ages. The place runs 20+ hours a day and the 32a seems to be a standard presumably so they can be swapped out promptly. New DB reauired.

In this sort of scenario I really doubt the lack of RCD protection for those sockets represents anything more than a C3 code, so no need to replace the DB.

If a new TPN DB is needed for other reasons, you might find it is cheaper to change the 3P sockets for ones with the RCD built in than to install many 3P RCBO, that way it is also simpler for the operator to reset any RCD that does trip.

The risk assessment these days applies only to sockets where they are under some form of electrically skilled control, I guess to avoid idiots plugging in an extension cable to outdoor equipment, etc. However, for a lot of ovens you might find they are too leaky to be used with 30mA RCDs anyway so that aspect would suggest going down the road @timhoward suggested of sockets with some means of limiting their use to those that are skilled enough not to do dumb stuff might be necessary (e.g. padlocks or similar, not necessarily high security ones!).

 

[Simon47]

Just a thought ...
Does there exist a plug/socket similar to BS4343 (Commando) but with two earth pins ?
Seems to me that (for this discussion) the primary requirement is as backup for failed earthing. Similar to RFCs where high leakage currents are expected require high integrity earthing, having duplicated earth paths would go a long way to mitigating the risks.

 

[Teddy Lop]

Just a thought ...
Does there exist a plug/socket similar to BS4343 (Commando) but with two earth pins ?
Seems to me that (for this discussion) the primary requirement is as backup for failed earthing. Similar to RFCs where high leakage currents are expected require high integrity earthing, having duplicated earth paths would go a long way to mitigating the risks.

That's a great observation. And once again regulatory obligations and market options diverging.

From what I've observed doesn't the German schumo socket have dual earth contacts? Although they can be reversed too so it might be for that reason.