Any Suggestions Would Be Much Appreciated

[Lukerc]

Hello,

220V 3P+E SUPPLY.

POLYCARBONATE PANEL
63A TP ROTARY ISOLATOR
4x 16A 220V 2P+E SOCKETS.
PROTECTED BY INDIVIDUAL 16A 30MA 2P 'C' TYPE RCBO'S.
SOCKETS WIRED USING 2 LINES PER SOCKET SO (L1-L2) (L2-L3) (L1-L3) (L1-L2).

I've looked at protecting the sockets with 2P ABB RCBO'S which offer overload protection in both poles.
The issue is they are expensive compared to standard L+N RCBO'S.

I'm thinking of using an incoming RCD and protecting each socket with a DP mcb to cut costs.

Just wondered if any of you more experienced spark's out there have any suggestions on the best and most cost effective way to protect this system?

Also with regards to RCD testing, as there isn't a neutral present and I've got 110v between phase and earth, I think I may have issues taking readings?

Again any suggestions or advice would be much appreciated.

 

[Marvo]

Am I understanding the setup correctly? You have sockets which are 2-pin + earth and they're 240v (110v - 110v) across the two pins.

Just out of interest is the supply coming from an isolating transformer?

If you use one main RCD on the incoming supply it would need to be a t-pole RCD to ensure that no socket has one phase remaining in the case of a trip and there might be a nuisance factor where one faulty circuit means all sockets lose supply.

 

[derbylad]

Hello,

220V 3P+E SUPPLY.

POLYCARBONATE PANEL
63A TP ROTARY ISOLATOR
4x 16A 220V 2P+E SOCKETS.
PROTECTED BY INDIVIDUAL 16A 30MA 2P 'C' TYPE RCBO'S.
SOCKETS WIRED USING 2 LINES PER SOCKET SO (L1-L2) (L2-L3) (L1-L3) (L1-L2).

I've looked at protecting the sockets with 2P ABB RCBO'S which offer overload protection in both poles.
The issue is they are expensive compared to standard L+N RCBO'S.

I'm thinking of using an incoming RCD and protecting each socket with a DP mcb to cut costs.

Just wondered if any of you more experienced spark's out there have any suggestions on the best and most cost effective way to protect this system?

Also with regards to RCD testing, as there isn't a neutral present and I've got 110v between phase and earth, I think I may have issues taking readings?

Again any suggestions or advice would be much appreciated.

the cost of the materials is not your concern,price the job using the most suitable equipment and if the client cant afford it then they cant get the Job done.
also why no neutrals at sockets?

 

[Lukerc]

Am I understanding the setup correctly? You have sockets which are 2-pin + earth and they're 240v (110v - 110v) across the two pins.

Just out of interest is the supply coming from an isolating transformer?

If you use one main RCD on the incoming supply it would need to be a t-pole RCD to ensure that no socket has one phase remaining in the case of a trip and there might be a nuisance factor where one faulty circuit means all sockets lose supply.

Yes two hot wires 110v each leg. The panel is for a customer up north. To my knowledge it is going to be installed on a ship generating 440v 3phase then being stepped down to 220v 3phase via an isolating transformer.

Yes the idea was to use a 4P RCD and mcb's, yeah the nuisance factor is why I looked at individual rcbo's.

 

[Lukerc]

the cost of the materials is not your concern,price the job using the most suitable equipment and if the client cant afford it then they cant get the Job done.
also why no neutrals at sockets?

Just want to be competitive on the price is all, as long as I'm still offering a good level of protection I'm happy

It is a 3phase and earth supply, so delta configuration.

 

[Marvo]

..........To my knowledge it is going to be installed on a ship generating 440v 3phase then being stepped down to 220v 3phase via an isolating transformer.......

Ahh, a marine installation might have a special set of requirements but essentially what you have would be equivalent to the kind of setup you see on a building site. The difference with marine is that if it's a metal hull ship, barge or rig then corrosion is caused by standard supply arrangements such as TN-C-S so they using isolating transformers and avoid N-E bonds at the supply source.

I'd suggest you refer to the customer for their preferred spec.

 

[Lukerc]

Ahh, a marine installation might have a special set of requirements but essentially what you have would be equivalent to the kind of setup you see on a building site. The difference with marine is that if it's a metal hull ship, barge or rig then corrosion is caused by standard supply arrangements such as TN-C-S so they using isolating transformers and avoid N-E bonds at the supply source.

I'd suggest you refer to the customer for their preferred spec.

I see, that makes sense.

I would be using a standard RCD tester to take my readings, my only worry is that it won't allow me to proceed as I will have 110v to earth and no neutral present.

I've only ever tested at 230V to Earth on a 415v supply or 55v to earth on a 110v.

220v Is a new one for me

 

[malcolmsanford]

Are you an English based sparks, just that your using terms like hot wires which are American.

If this is going onto a ship then you may have to refer to the BS 8450 for on board equipment.

When you say there is no neutrals then your not going to have any 117 volt circuits. Your relying on the 2 phase giving you the 220v. This is an American system, why are they using this on a British ship, do you know?

 

[Lukerc]

Yes I'm based in the UK. I should of said 2 phases.

I know I won't have any 110v circuits but when carrying out the RCD test I will be testing between phase & earth which will be
110v.

I don't know why they are using this system, I just want to make sure that I'm able to test the panel using standard test
equipment.

It may be like you say that I will have to refer to BS 8450 for further information.