3 phase earth leakage protection

[ians]

A trick question for all you smart fellas.

When installing a 3 phase socket outlet in a shop which is only going to feed 1 appliance with a cord not longer than 3 meters, is earth leakage protection required?

[Dave A]

It's certainly possible in terms of 6.7.5.5.

In fact there's a high possibility for 6.7.5.5 b) to be applicable.

6.7.5.5 The following do not need earth leakage protection:

b) a socket outlet that complies with SANS 164-4 and that is intended only for the connection of an appliance for critical application (such as emergency lighting, a deep freeze, a burglar alarm, data processing equipment, or life-supporting equipment);

[AndyD]

I'd also say it was a possible yes. Lots of variables though, if the socket was fed from a control panel then it could fall outside the general installation regs.

[ians]

Will be fed from a standard 3 phase DB. It will be the supply for stationary appliances used for heating and cooking

[bergie]

i would say it has to be on earth leakage relay. if the socket outlet was dedicated for 1 particular appliance that shouldnt be on earth leakage ,such as alarms,etc then only can it be left off.

[ians]

It all starts at the design of the electrical installations.

A little while back i got into a dispute with a clever person (electrician) who knew everything and tried to make a fool of me in front of his customer, not a wise move. I may act like a fool most of the time but I do that to protect myself.

My point is when you design an electrical installations there are a lot of factors which need to be taken into account. One of the reasons i very seldom respond to electrical questions on public forums.

I have been doing some research into this issue with regards to 3 phase sockets and earth leakage protection and there is some interesting things popping up. For now all i am going to say is not all 3 phase sockets have to be on earth leakage. I need to finish my research before i say anymore.

The project i am busy with will be hugely affected by earth leakage and i have noted that none of the other installations use earth leakage protection. The meeting with the engineer is going to be rather interesting.

[AndyD]

I think the simple answer would be that yes, all 3phase sockets would require E/L protection unless they somehow qualify as an exemption. If it's cooking equipment in a commercial kitchen then I'd say it would be a good idea to RCD protect them anyway given the type of abuse they'd usually suffer in that environment. Under normal circumstances I don't see the point of having kitchen equipment on plugs and sockets, it just provides another place where faults can occur.