Generator connection and RCD advise

[BMW]

Hi wonder if you can help. Been asked to connect a new Hyundai 5KW generator. Basically it just to feed 2 double socket to power servers in the case of a power cut. Now I gather its just plug and sockets (32A) SWA and regular twin sockets with indicators on but, What about protection? do I need a 32A socket that the generator plugs into with an RCD if so do I just run an earth rod like a TT system? should it be 30MA? Is they anything else I should Know?.

Sorry been a sparky for years but never been involved with this before now.

Cheers

 

[ian.settle1]

Hi wonder if you can help. Been asked to connect a new Hyundai 5KW generator. Basically it just to feed 2 double socket to power servers in the case of a power cut. Now I gather its just plug and sockets (32A) SWA and regular twin sockets with indicators on but, What about protection? do I need a 32A socket that the generator plugs into with an RCD if so do I just run an earth rod like a TT system? should it be 30MA? Is they anything else I should Know?.

Sorry been a sparky for years but never been involved with this before now.

Cheers

Never seen a 30 Mega Amp RCD

 

[davethsparky]

For a start you need a 32A plug that the generator connects in to, the socket is mounted on the generator. Think about which bit is normally live and this will make sense. i'd be inclined to fit a surface mounted plug (often called appliance inlet) and have a short 32A extension lead to connect to the generator socket. If the generator doesn't have sufficient overcurrent protection you'll want to think about putting some in.

Afraid I cant help much on the rest of the question as my involvement with generators is normally bigger stand-alone units for outdoor events. Do check the voltage regulation of the generator aswell, many if those miniature sets have very poor voltage regulation which computers don't like.

 

[Marvo]

Can you give us the exact model number of the generator?

 

[BMW]

Can you give us the exact model number of the generator?

Hi

Yes its a DHY6000SELR Portable Generator rated 5KW, 22.6 A, voltage 115/230

 

[Marvo]

Are you looking to use it as a permanently installed back-up generator? Will it be supplying sockets that are also supplied by DNO power ie will there be an automatic transfer switch or an automatic mains fail control panel??

 

[BMW]

Are you looking to use it as a permanently installed back-up generator? Will it be supplying sockets that are also supplied by DNO power ie will there be an automatic transfer switch or an automatic mains fail control panel??

Hi No it is permanent but not connected to the DNO these sockets are only connect to the generator so i guess went power down the plug into these dedicated sockets and start the generator.

 

[davethsparky]

You need to make sure the generator is allowed to start and stabilise its output before connecting the load. You never start a generator under load.
This could be by a system of training and warning signs for a set up like this.

 

[BMW]

Cheers yes good point apart from that any issues? I was going to use a socket by the generator with the built in RCD and put a earth rod in. I'm guessing that's it?

 

[Marvo]

Yep, if it's just supplying sockets that aren't DNO supplied then it's straightforward. I'd knock in a decent length earth rod (at least 2x2.3 rods coupled together to get a stable Ra reading that's within your local reg requirements. You'll need to bond the chassis. Check the installation instructions to see if the N and E is already bonded internally in the generator.

 

[davethsparky]

Cheers yes good point apart from that any issues? I was going to use a socket by the generator with the built in RCD and put a earth rod in. I'm guessing that's it?

I assume you mean an rcd socket for the outlet? You need a plug for the connection to the generator which you won't find with a built in rcd.

 

[Knobhead]

I can see this ending badly.

I’ve gone through the specification, it looks good. But no mention of if it is centre or end tapped. It being dual voltage I would suspect centre tapped 230V which is bad news.
If it does prove to be centre tapped, double pole protection is required for any output.

Sorry to be a wet blanket, but generators and domestic equipment can be dangerous.

 

[Marvo]

I also couldn't find info on the internal configuration but I noticed that particular generator is sold as a 'back-up' power solution in several countries and is for use with automatic transfer and AMF so hopefully it will be end tapped but only the manufacturers literature will confirm. If it's center tapped I wouldn't use it on IT equipment, the high N-E voltage could cause damage.

 

[Engineer54]

Don't you have any manufacturer's data with this unit eg. wiring schematic, and recommended earthing and wiring hook ups??

Another important factor, is the proposed load that this standby gen-set is going to supply, it really needs to be over 50 to 60% if your not going to coke up the drive engine. So i hope this genset isn't sized too big for your needs on these 2 servers?

 

[Knobhead]

Unfortunately many countries use centre tapped 230V.

It’s up to the OP to be sure on this.

 

[BMW]

Many thanks

 

[Knobhead]

I take it you don’t intend to give any further information.