Couple of electrical questions

[lymmranger]

Are you not confusing MCB and RCD????????

 

You should only have ONE RCD fitted ideally in a consumer (distribution) unit. This is irrespective of how many circuits or sockets that you may have

 

This will then allow you to have a number (depending on size of consumer unit) of circuits, each protected by an MCB

 

Think of the RCD as a master safety trip switch which monitors the whole system for (earth) faults, and upon discovery switches off the power instantly

 

The MCB are likened to fuses they will trip on overload, but not necessarily trip the RCD.

 

A 3 to 5 circuit consumer unit should be more than ample for a boat.....

 

I have 2 "ring" cicuits, a circuit for the imersion heater and one controlling the battery charger

 

To be really safe you should choose an RCD with a quicker response than the supply (boatyard?) This way you wont be always tripping the supply but tripping just your boat.

 

Please, please, please make sure you fully understand what you are doing, we already have a virtual pub, we do not want a virtual chapel of rest!

[John Orentas]

Hi Ranger.

 

If there is any confusion it may well be that many people these days use combined units, RCD + MCB this is often a more cost effective way to do the job. It also has the advantage that having two RCD's only one of them will trip under a fault condition so you won't have a total black-out.

 

Thinking about it I suppose you could argue that a master isolator would then be needed, not sure about that.

[DHutch]

Speaking of getting it the right way round I've just had a look at the socket in screwfix and it is the wrong way round.

Yes, thats not what you want, do not fit on of these for the supply to your boat!

 

As said above, you need a plug, as in you first post.

- Infact, im my haste i posted the wrong farnell code, sorry about that.

 

 

Daniel

[lymmranger]

John, you are making the mix more cloudy!!!!

 

I think you are talking about a "split" board which effectively has a seperate RCD for each half of the unit...

 

I wasn`t aware you could get them smaller than a 12 way board which is a bit OTT for a boat! I thought my 4 way was big!!!!

 

Anyway back on topic....

 

240v AC should not be DIY`d - if you know what you are doing then great, if not stay away!

 

Remember you could kill people! (you can smell gas/petrol/diesel, you cannot smell electricity)

 

(We wont even go into badly installed electrics causing electrolysis and eating every boat in the marina)

[DHutch]

John, I think you are talking about a "split" board which effectively has a seperate RCD for each half of the unit...

No, i bealve he;s talking about a RCBO

 

RCD/RCB—Residual Current Device (formerly known as a Residual Current Circuit Breaker) - detects current imbalance. Does NOT provide overcurrent protection.

 

MCB—Miniature Circuit Breaker - A circuit breaker is an automatically-operated electrical switch which is designed to protect an electrical circuit from damage caused by overload or short circuit.

 

RCBO—Residual Current Breaker with Overcurrent protection - combines the functions of an RCD and an MCB in one package. In the United States and Canada, panel-mounted devices that combine ground(earth) fault detection and overcurrent protection are called Ground Fault Circuit Interrupter (GFCI) breakers; a wall mounted outlet device providing ground fault detction only is called a GFCI.

 

ELCB—Earth leakage circuit breaker. This detected earth current directly rather than detecting imbalance. They are no longer seen in new installations for various reasons.

 

- Info extracted from varous wiki pages.

 

 

Daniel

[Amicus]

Pin that up somewhere Daniel

[Moley]

Thanks Daniel.

 

RCD, RCB, MCB, RCBO, GFCI, ELCB, RCD again, BSS,

 

OTT!

 

If I find the SOB who started all these ABRV8Ns I'll be done for GBH or ABH or wind up with an ASBO at the very least.

 

So I think BW have got an RCD on the pontoon, then I've got an RCD and two MCBs on my NB. OK?

 

Bottom line is, I'm bloody careful with electrickery, I know what I'm doing, but treat it with considerable respect, and no-one, myself included, has ever taken a kick from anything I've wired. Nor will they.

Edited March 14, 2006 by Moley

[wrigglefingers]

Thanks Daniel.

 

RCD, RCB, MCB, RCBO, GFCI, ELCB, RCD again, BSS,

 

OTT!

 

If I find the SOB who started all these ABRV8Ns I'll wind up with an ASBO

 

So I think BW have got an RCD on the pontoon, then I've got an RCD and two MCBs on my NB. OK?

 

Bottom line is, I'm bloody careful with electrickery, I know what I'm doing, but treat it with considerable respect, and no-one, myself included, has ever taken a kick from anything I've wired. Nor will they.

 

As the late, great Linda Smith said "so many people knock ASBOs; but ....... it's the only qualification some of these kids will ever get".

 

Is it customary for your eyeballs to start bleeding after considering electricity matters for more than 3 minutes?

 

Jill

[DHutch]

So I think BW have got an RCD on the pontoon, then I've got an RCD and two MCBs on my NB. OK?

 

If i had to guess... (from what ive seen, understand, depending on the moorring, boat yard etc)

 

1) The boat yard will have a three phase supply, feeding though the boards fuses, into a Consumer unit.

 

2) There will them be a Dis board for the phase in question, with 1 or 2 RCDs, and then serveral MCBs

 

3) BW will have a largeish Dis board with one or more RCDs Followed by a MCB for each piller, or area of pillers (ie a finger of a marina, or whatever)

 

4) The BW piller will have an a MCB per socket/mooring often fused very low (say 5amps or less) to limit usage

 

5) And you will have an RCD followed by one or more MCB's (We have three, ring main, charger, 240v lighting)

 

However

- If the yard has only a single phase supply, 1) wil not exist.

- 2) & 3) may well be one of the same thing

- There may be another RCD in each piller

- And you boat may have more/less MCB

- And they may well be some RCBOs in there.

 

Also, there my be some utter crap wiring in there two, our shoreline when we first where at tarleton considted of an (un-armored) 13amp domestic extention lead, which feed 3 daisy-chained 4way addaptors, and was fitted with a 16amp plug at the boat yard, and pluged into a socket fused at 16amps, that triped about twice a day (not very supprising)

- I spend about a day wondering though the yard trying to trace where this 16amp socket was fed from, and could trace it at all!

- But i found some excenent bodge jobs on my way, and a lot of decaying rubbish (some of the dis board had holes that size of by arm where thay had just rotted though!)

 

 

That said, the new owners where working fast on sorting this out, and by the end of it our side of the canal had a nice big armored cable across to us, with several boxes, each with 4/6 sockets, each with there own breakers and meter.

- Including one with a threephase supply, so that they can do the odd welding job over there.

- That didnt go off once over the couase of about a fortnite, excpet once when they where working on some wiring "upstream" an turn it off deliberatly.

 

 

Daniel

[Moley]

 

ENUF. FO

Edited March 15, 2006 by Moley

[ChrisPy]

This has been mentioned on previous threads - I belive its only an RCD requirement not a BSS one??

 

Moley's boat doesn't need to comply with RCD as its not a "new build".

it's nothing to do with RCD or BSS or new builds, it's just safe practice.

 

if the phases are reversed somewhere through the marina or connecting wiring then the neutral may be live and the live neutral. (Can you trust that all the wiring by others is correct?) In which case putting a single phase isolator on the brown live wire (which is actually neutral) will give you a false sense of security. So the prudent course is to isolate both wires and to have a polarity indicator to let you know the incorrect condition.

[Jim Riley]

I've just got a replacement 240v "c" socket for my caravan, it has a flap on the front to cover the socket, meant to fit in the wall of a caravan, a bit neater than the sockets shown above, got it from the caravan place just north of carnforth.

[DHutch]

Like this one amicus posted?

http://www.canalworld.net/forums/index.php...&cmd=si&img=775

[lymmranger]

No, i bealve he;s talking about a RCBO

 

RCD/RCB—Residual Current Device (formerly known as a Residual Current Circuit Breaker) - detects current imbalance. Does NOT provide overcurrent protection.

 

MCB—Miniature Circuit Breaker - A circuit breaker is an automatically-operated electrical switch which is designed to protect an electrical circuit from damage caused by overload or short circuit.

 

RCBO—Residual Current Breaker with Overcurrent protection - combines the functions of an RCD and an MCB in one package. In the United States and Canada, panel-mounted devices that combine ground(earth) fault detection and overcurrent protection are called Ground Fault Circuit Interrupter (GFCI) breakers; a wall mounted outlet device providing ground fault detction only is called a GFCI.

 

ELCB—Earth leakage circuit breaker. This detected earth current directly rather than detecting imbalance. They are no longer seen in new installations for various reasons.

 

- Info extracted from varous wiki pages.

Daniel

 

Cheers Daniel,

 

feeling old again now!!!

 

it is a couple of years since had to look up stuff like this.......

 

they will invent machines that fly soon!!!!

 

Mind you I still stand by my warning!!!!!!!

Edited March 15, 2006 by lymmranger