PaulRainbow
Well-Known Member
This style of thing should do you: Electric Hook Up For Camping with RCD & MCD Campsite Approved Waterproof unit | eBay
(just an example, other options exist)
Recommend me a RCD please
- Thread starter Gixer
- Start date
This style of thing should do you: Electric Hook Up For Camping with RCD & MCD Campsite Approved Waterproof unit | eBay
(just an example, other options exist)
Gixer
Well-Known Member
Oh no, I really hoped this wouldn't come up. Both batteries are alternator charged by using the.... both switch. To be honest I never use both as my poor 1GM doesn't sound very happy when you connect both batteries.
Even though you have recommended a VSR to me before I didn't pull the trigger on one as I was concerned about permanently losing HP on such a small engine.
Feel free to give me a dressing down
Graham376
Well-Known Member
Agree but, UK boats often visit Europe with 50/50 chance of reverse polarity so double pole makes sense.
PaulRainbow
Well-Known Member
Some UK boats might visit Europe, but the vast majority of UK boats are not fitted with double pole circuit breakers.
Even if the polarity is reversed, a single pole circuit breaker will trip. The issue is, it will trip the neutral supply, so anyone working on the electrics could still get a shock. The simple solution for UK boats that were built with single pole breakers is to fit a reverse polarity warning lamp on the AC panel. If you're wiring your own boat (or having it wired) and are likely to be visiting Europe, you can always specify double pole breakers.
Channel Sailor
Well-Known Member
In the suggestion to install a little garage or builders consumer unit, there is in these examples a double pole RCD. The RCD protects against electric shock and is also the main isolator for safety during maintenance. The MCB is mainly there for over current protection, in other words to reduce fire risk. if there was excess current drawn the MCB will still trip to prevent fire or overheating damage, even if the polarity is reversed.
if you are stuck holding a live wire and want to wait a few seconds for a 16a MCB to trip off, then would will be disappointed because probably you will need to be dragged off it by someone else using and insulated rope/pole or if lucky it will have thrown you off with a muscle spasm. Hence why RCDs are such a good idea.
Any professional working on 230v circuits would switch off what they thought was the isolator, then use a proven voltage tester to make sure the power is off. Only then will they touch live terminals.
Perhaps this thread is highlighting that 230V installations on a yacht should be professionally installed. Or maybe the off the shelf products as were first suggested (the long lead time item) have their merits. The saving grace with 230v on a boat in a uk marina is there will be a tested RCD in the pillar on the pontoon, so a DIYer who makes an error is much less likely to kill themselves or anyone else.
Beware of tatty boat yard trailing 13A leads appearing from from under questionable plywood boxes. Sure it could be all proper under the lid and most likely it is OK, but worth enquiring further or put your own RCD in line at the plug top.
if you are stuck holding a live wire and want to wait a few seconds for a 16a MCB to trip off, then would will be disappointed because probably you will need to be dragged off it by someone else using and insulated rope/pole or if lucky it will have thrown you off with a muscle spasm. Hence why RCDs are such a good idea.
Any professional working on 230v circuits would switch off what they thought was the isolator, then use a proven voltage tester to make sure the power is off. Only then will they touch live terminals.
Perhaps this thread is highlighting that 230V installations on a yacht should be professionally installed. Or maybe the off the shelf products as were first suggested (the long lead time item) have their merits. The saving grace with 230v on a boat in a uk marina is there will be a tested RCD in the pillar on the pontoon, so a DIYer who makes an error is much less likely to kill themselves or anyone else.
Beware of tatty boat yard trailing 13A leads appearing from from under questionable plywood boxes. Sure it could be all proper under the lid and most likely it is OK, but worth enquiring further or put your own RCD in line at the plug top.
Aurai
Well-Known Member
Happy to discuss with anyone, metal consumer units are only “required“ in dwellings, plastic ones have a long life ahead of them. Though manufacturers may limit our choice. A plastic one on a boat like mine, highly recommended. As mentioned, you are buying into RCD protection, first and foremost. As Paul mentioned, stick with 2.5 mm as not sure you can wire 13A sockets with 1.5 mm. unless fused down to 6A. Distances on small boats do not usually affect the cable selection, other than avoiding domestic twin and earth.
JumbleDuck
Well-Known Member
I couldn't find a plastic one when I was wiring my barn. Didn't realise they were still available.
Gixer
Well-Known Member
Thanks guys, this info is great.
l’ve gone for the Plastic RCD mentioned by channel sailer and will buy 2.5mm artic cable for all wiring.
l’ve gone for the Plastic RCD mentioned by channel sailer and will buy 2.5mm artic cable for all wiring.
dankilb
Well-Known Member
Can I ask any opportunistic question on the topic - any advantage to specifying a lower amperage RCD, to match the shore power socket rating (i.e. 16amps)?
I might populate an empty consumer unit so could choose any rating.
I might populate an empty consumer unit so could choose any rating.
PaulRainbow
Well-Known Member
Short answer, no. The MCBs will provide overload protection.
prv
Well-Known Member
At least in a northern French marina, I’ve never had a shore power connection with the polarity reversed (I have a tester built into my panel).
Pete
Graham376
Well-Known Member
Seem to remember some of the old French ones had a male earth pin sticking out of the socket to stop reverse polarity. We have a 50/50 chance in boatyard we use elsewhere but I just leave as is. Have a double pole isolator in supply which is always off if I'm playing with 220v.
VicS
Well-Known Member
No .
The current ratings you see , such as 25A for the caravan unit mentioned at the top of the thread and 40A for the garage unit mentioned later, is the maximum current carrying capability for which the unit is rated. It is not the current at which it will trip. In fact RCDs are not designed trip in overload situations. That's what an MCB is for
You should choose an RCD rated above the maximum current you will draw.
It is the figure in mA. (most usually 30mA) which is the relevant figure for an RCD and defines the current ( vs time) flowing somewhere it should not (eg through someone touching the line conductor) which will trip the device
10mA devices may be used in some situations where a high level of protection is required. 100mA devices may be used for fire prevention
For more information, and an explanation of the way in which an RCD works, seek out the videoon RCDs in John Ward's excellent series of videos.
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prv
Well-Known Member
That's the standard French domestic socket (the common British idea that there's a single "European socket" across the whole continent is incorrect, though there's a fair degree of interoperability) but the marinas I've been to (admittedly not a large sample) all used the same 16amp ceeform connector as the UK.
Pete
dankilb
Well-Known Member
Thanks both. Clears that up. ??
Think I’d gotten myself confused research RCBOs and assumed the RCD was doing the same. I’ll watch the videos as suggested! But I get now that it detects the earth leakage and the MCBs do the overload.
BabaYaga
Well-Known Member
Or rated at? In a system using 16 A ceeform plug/socket and 16 A MCB, surely a 16 A rated RCD must be adequate?
TernVI
Well-Known Member
Many domestic consumer units have 'incomer' RCCBs which combine leakage current trips with over current trips.
The idea being that you might load up all your ring mains and a couple of electric showers or something, which could blow the 'company fuse'.
I'm not sure they are available at low enough ratings to protect a marina hook up cable though?
The idea being that you might load up all your ring mains and a couple of electric showers or something, which could blow the 'company fuse'.
I'm not sure they are available at low enough ratings to protect a marina hook up cable though?
VicS
Well-Known Member
Yes that will be adequate
dankilib asked , if there was any advantage to specifying a lower amperage RCD, to match the shore power socket rating .
No there is no advantage
The combined MCB and RCD is an RCBO.
16 amp ones are available
Remember when choosing MCBs, or RCBOs, there are several different "types" with different tripping characteristics.
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TernVI
Well-Known Member
RCBO's are generally to replace the individual MCBs, for instance when you want earth leakage protection on an individual circuit, so tripping the lawnmower doesn't turn the freezer off or something.
I'm talking about the double width main switch/RCD/overload which does the whole box.
The one in my garage has a fuse symbol as well as the RCD symbols.
Not all RCD breakers have the fuse symbol on though....
PaulRainbow
Well-Known Member
An RCCB is a Residual Current Circuit Breaker it does not provide any over current protection, you were mistaken in post #37 when you said it did.
An RCBO is a combined RCB and circuit breaker, Residual Current Breaker with Over-Current device. If the device in your garage is a combined RCD/breaker, it's therefore an RCBO.
An RCBO can be fitted in place of the RCD, with a current rating based on where it's installed, on a boat with a 16a shore power connection, that's obviously a 16a RCBO. It can, as you say, be fitted in place of MCBs too, but that would (i think) be rare in a domestic installation, more common in industrial installations.