Boats and the need for residual current devices (RCD's)

[juggernaut]

Fella's,

I'm having some electrical work done on my cruiser and the electrician says I need to install an RCD on the generator line and another one on the shore power line.

The boat is a 2006 Sea Ray and was not a grey import. The boat has RCD's for each 240 volt power point. Lighting is 12 volts throughout. The electrician says my 240 volt electrical appliances aren't protected. These include stove top, reverse cycle aircon, hotwater system, etc. These items are hardwired.

Just curious as to whether he is conning me or he is correct. Anyone know?

Thanks in advance.

[rayken1938]

Trip the rcd and see if stove etc still work.No idea what the standard is but safety is paramount. What do you think your life is worth?

Cheers
Ray

[juggernaut]

No RCD on the Stove - so yes it still works. Each power outlet has an RCD only. From what I can see even the local WA laws applying to houses only require RCD's on power points and lighting circuits.

https://www.commerce.wa.gov.au/energysafety/rcd-fact-sheet

Worksafe laws also seem to be similar.

No RCD on the hot water circuit in my office either.

Don't get me wrong - I'm all about safety - I'd just like to know what the laws are - if they are necessary I would have thought they would have been covered by laws.

[rayken1938]

I am in qld and no rcd on hot water but is on hard wired air cond.
From memory they are not necessary on stoves and hot water systems as there is always a small amount of leakage in most elements, But its 15 years since it had anything to do with it so could have changed.
Cheers
Ray

[Yobbo70]

I have a RCD on my shore power in, and it use to trip every now and then during storms until I found I had a small bit of rain water coming in from where the flybridge attaches to the cabin windows (right next to my sons berth), if i had no RCD I might have had "live" water in the boat.

[juggernaut]

Hi Yobbo,

There is an RCD on the shore power GPO on the jetty at the marina where I plug my shore power cord into but not actually on the line in on the boat. Obviously necessary in case someone drops the other end of the cord in the water when live.

To clarify - is your RCD on the boat or on the shore power GPO or both?

[trevs1979]

one rcd protecting all power points ,stove,hot water and reverse cycle is just asking for trouble if he intends on installing a 30ma rcd


id be doing either of the following
(1) nothing if all units are hard wired and correctly earth
(2) an rcd for each unit stove,hot water,aircon
(3) install a 100ma rcd on the shore power and generator...... that way you still have cable protection and with correct earthing hard wired devices would have below the lethal touch voltage (number 3 is what id be doing )

cheers trev

[ranmar850]

There is an AS (Australian Standard) which must be followed if a boat is to be plugged into shore power. Sorry, I don't have ready access to these any more as I have changed jobs and no longer have free access to the SAI Global site. I would assume your electrician knows what he is talking about. The installation must be certified by him once done as being compliant.

[shane450]

Would you make way without you boat being insured , RCD s are insurance for you and your families health and safety .

its a no brainer IMO

[BM]

In house wiring, appliances such as stove tops and wall ovens are direct wired to the mains and don't go via an RCD. Similarly, split system aircons also don't get wired via an RCD. If you wire a split system via an RCD it usually won't work.

[juggernaut]

Fella's,

I'm going with the RCD's despite everything being hardwired including TV's, microwaves, stoves, water heater etc. Any prob's and I'll be getting the leccy to sort it out.

All power outlets currently have their own individual RCD's as it came from the Sea Ray factory.

[marto78]

You could very well be up for a new stove and hot water system as well if they dont pass an insulation resistance test and start tripping the new rcds. More money for the sparky.

[marto78]

Hi Yobbo,

There is an RCD on the shore power GPO on the jetty at the marina where I plug my shore power cord into but not actually on the line in on the boat. Obviously necessary in case someone drops the other end of the cord in the water when live.

To clarify - is your RCD on the boat or on the shore power GPO or both?

If there is an rcd on the shore power then everything run from that shore gpo on will be protected by that rcd including your stove, ac and hot water.

I was also under the impression after a previous discussion on here a couple years ago that an rcd didn't work when hooked up to a generator.

[Feral]

I vaguely remember than having multiple RCD's on one circuit is a no no. IE if the shore system has one installed on the point your drawing power from, it might not be a good idea for you to then have one after it. (They don't function properly), also stoves and similar heating elements are notorious for not being RCD friendly.

[trevs1979]

have to agree with marto it is a legal requirement for 63amp and below both 3 phase and single phase outlets to be protected by an rcd on the wharf your docking at

you will have no worries with an rcd working on a genset as long as the star point of the gen is to earth ......(ie) mem link

multi rcds installed on one circuit are a pain in the ass as the end users always forget where they are all installed and cant figure out why the power isnt working but it will not effect function


what i cant figure out is why you need two rcds im assuming both the shore power and generator on board both feed into the same switch board on your boat in which case all out going circuits could be protected with one common unit both generator and shore power im hoping have some interlocking to prevent both being on at once or do you plug the units into the switch board ...

cheers trev

[juggernaut]

Fella's - this is my concern - that I'm going to have more RCD's than I can poke a stick at - and I hope it isn't going to cause any problems - as everything is working fine at the moment. Surely the shore power GPO RCD is going to protect any hardwired equipment. And on top of that all my power outlets are already individually protected.

Sea Ray have probably made more boats over the years than just about anyone else and I haven't heard about any safety concerns with their electrical setups. Still, if the law requires that I must have more RCD's then I guess I have too.

Trevs,

The shore power and generator feed the AC panel independently via switches and yes there is a lockout on the panel to prevent the shore power and generator feeding into the AC panel simultaneously. So I guess there are really two independent sources of AC power to the main board.

[ranmar850]

you will have no worries with an rcd working on a genset as long as the star point of the gen is to earth ......(ie) mem link That's MEN link,and yes that is correct. Which is why you can't just plug an RCD portable board into an inverter generator , and expect protection,but that's another story.


also stoves and similar heating elements are notorious for not being RCD friendly. Also correct, sheathed heating elements are notoriously leaky, and may give you problems with RCDs

I wish I could access that Australian standard, I could give you a firm ruling.

[barney1979]

The only answer to you question is to read AS 3004.2. That is the electrical Australian standard for recreational boats and it covers where rcds are required.
Unfortunately I don't have a copy, but the sparky carrying out the work should, So if it was me I'd ask him.


Sent from my iPad using Tapatalk

[trevs1979]

Fella's - this is my concern - that I'm going to have more RCD's than I can poke a stick at - and I hope it isn't going to cause any problems - as everything is working fine at the moment. Surely the shore power GPO RCD is going to protect any hardwired equipment. And on top of that all my power outlets are already individually protected
you are not going to have any safety issues buy installing more rcd units only potential hassles and thats only if you have earth leakage on the stove,hot-water and air-con as many people have already said heating elements can and do on occasion have low earth resistance which can cause rcd units to trip .

in most cases this is due to lack of use as moisture is absorbed into the heating element without an rcd this is removed once the element is heated again and no ones even realizes

and your correct the shore power you connect too should have an rcd

one benfit of having multi rcd units is they can and do fail more so if never tested (ie tripped monthly ) if anything ask your electrician to test your rcd units with an rcd tester on both wave forms and provide the test trip times he should have a test unit with him if not ask if he can borrow one off somebody who does

Sea Ray have probably made more boats over the years than just about anyone else and I haven't heard about any safety concerns with their electrical setups.
i agree in part with this ive seen multi million dollar ships with major defects repeated over and over again

Trevs,

The shore power and generator feed the AC panel independently via switches and yes there is a lockout on the panel to prevent the shore power and generator feeding into the AC panel simultaneously. So I guess there are really two independent sources of AC power to the main board.

sounds correct in config although they are both feeding onto a common swbd hence the lockout to stop two feeds being on at once as i stated earlier if it was me i would leave as is and install one 100ma rcd to cover the stove,hot water ,and air con after reading an earlier post of yours you say you are hard wiring your tv and microwave remember now each time it fails you need an electrician to rewire it instead of just buying another and plugin it in yourself