Tripping RCD's / new installation?

[Strads]

Morning all - and electrical one that I'd appreciate some feedback on the potenial issuse/cause and possible solutions.

 

Firstly - we have 24v electrics a Victorn 3000/70 24v Phoenix invertor.

 

We have recently wired the boat using artic blue cable and a proper distribution box with 16a RCD trip etc

this has 2 ring mains and spur for immersion, boat mans cabin and Stove - more on that in a moment

 

we are connected in the marina to mains power and that also has a 16 A rcd.

 

yesterday we commisioned our heritage stove, and when we turned it on both RCD's tripped.

 

After re-setting they then "appeared" to be ok - eg not triping out..

the calibration / set up tests all went fine and the engineer took the readings and checked the systems - all ok.

 

we then returned last night and the RCD both tripped - repeatly - we did the obvious visual checks,,

 

but found that when we re set the boat rcd but not shore one the system ran fine of the invertor - the stove functioned and the rcd did not trip

the stove states it uses a 100w and has a 3 amp protection fuse - and other than a standard grunfoss central heating pump thats it.

 

 

 

Any one able to suggest reaons for this annomally? as we rather need to have the mains connected !

 

cheers strads

[Arnot]

Morning all - and electrical one that I'd appreciate some feedback on the potenial issuse/cause and possible solutions.

 

Firstly - we have 24v electrics a Victorn 3000/70 24v Phoenix invertor.

 

We have recently wired the boat using artic blue cable and a proper distribution box with 16a RCD trip etc

this has 2 ring mains and spur for immersion, boat mans cabin and Stove - more on that in a moment

 

we are connected in the marina to mains power and that also has a 16 A rcd.

 

yesterday we commisioned our heritage stove, and when we turned it on both RCD's tripped.

 

After re-setting they then "appeared" to be ok - eg not triping out..

the calibration / set up tests all went fine and the engineer took the readings and checked the systems - all ok.

 

we then returned last night and the RCD both tripped - repeatly - we did the obvious visual checks,,

 

but found that when we re set the boat rcd but not shore one the system ran fine of the invertor - the stove functioned and the rcd did not trip

the stove states it uses a 100w and has a 3 amp protection fuse - and other than a standard grunfoss central heating pump thats it.

 

 

 

Any one able to suggest reaons for this annomally? as we rather need to have the mains connected !

 

cheers strads

It sounds as though at some stage, neutral and protective earth have connected together.

 

Is the stove connected via a plug or a fused spur? If it's a plug, unplug it and using a meter check for continouity between the earth pin on the plug and either of the two phase pins. If the resistance is less that about 10kOhms you have a problem. If its a fused spur you will have to completely disconnect it and dothe same check on the wires that connect to the stove.

 

Hope this helps,

 

Regards

 

Arnot

[Berty]

Hi,

 

I agree with arnot, but I'd add that it sounds like you don't have proper RCD protection on your invertor circuit.

 

You can test this by buying a plug-in tester, which will also warn you of things like reverse polarity, which can be handy when you plug into to an unknown shore supply, which will properly test the RCD.

 

Note that using the test button on the RCD does not constitute a proper test.

 

(Rather than buying a plug in tester, it is possible to construct an appropriate test plug yourself, but I'll leave it someone else to tell you how. Getting it wrong is dangerous, and I'm not confident in being able to give clear enough instructions as to it's safe construction!)

 

If you don't have proper protection for your invertor circuit, you risk electrocuting yourselves or someone else in the event of a fault!

 

Cheers,

Berty

[Gary Peacock]

I have installed a lot of Heritages and Victron kit together without a problem so there aren't any issues there.

 

My money would be on the wiring of the thermostats programmer and pump etc if you have a problem here it can all work until such a time that a thermostat switches then all trip off.

 

The other one to look out for is any leaks getting into the electrics.

 

If you unplug the green supply plug in the Heritage you in effect isolate it from the system and can see if it still trips.

 

Is it a Uno or a Compact because they work in slightly different ways?

Edited July 28, 2009 by Gary Peacock

[Strads]

Guys

 

Thanks for the feedback so far - appreciated -

 

and makes me wonder - the RCD is linked with neutral and earth to ensure that they cut should any positive come into the contact / wiring anywhere etc.

 

We did that based on what we understood to be the appropriate method - I will check that later with a meter to see if there are any stray "volts etc"

 

 

re testers - re the victron etc.

 

Will re-read thie manual but until now all has worked fine - including the other electrics - specially when I did short a pair accidently (drilled through a wire!)

 

hence why I am puzzled as to why the spur to the stove is now casuing the additional issues !..

 

cheers

 

Gary,

 

Hi and thanks for yr comments -

 

Its an Uno model -

 

we have used a honeywell board to link the parts together and although we followed the wiring etc,

 

the engineer checked both the room stat and cyl stat and we had to move a wire on each and the board - but he check with his meter

this was needed to get the feed to pump. =

 

also he needed to add 2 feeders within the board to power the board - this wasnt clear from the wiring details with the stove or the honeywell directions

(these were the reccommened items for a Y valve installation)

 

we did discuss intallation and wiring a while back... and appreciate yr knowledge of these beasts etc

 

cheers

[Mrs Strads]

Is it a Uno or a Compact because they work in slightly different ways?

 

Gary

Strads forgot to say it is an UNO does that make a difference?

[nb Innisfree]

When we ordered our Victron Multiplus 3000-70-24 (Jan 2004) we were told it should be the later model which has auto E/N bond disconnect when plugged in to shorepower. I subsequently found out it didn't have this facility and looking at it's specs online it seems it never has been fitted to this model. The upshot of this is for us to enable RCD when on inverter power requires E/N bond to be made manually, but this needs disabling when on shorepower that has it's own RCD otherwise it will be tripped. We fitted a manual E/N switch.

 

Is it possible that you previously never actually tested you RCD on inverter? if so then this could be your problem

Edited July 28, 2009 by nb Innisfree

[Gary Peacock]

Gary

Strads forgot to say it is an UNO does that make a difference?

 

The Uno is actually a bit simpler because its only got one burner and the programmer in integrated into the cooker, it would still be a good idea unplug the green plug and see what happens.

 

You should really have a double pole isolator in the spur too to fully isolate the cooker if needed.

[Strads]

The Uno is actually a bit simpler because its only got one burner and the programmer in integrated into the cooker, it would still be a good idea unplug the green plug and see what happens.

 

You should really have a double pole isolator in the spur too to fully isolate the cooker if needed.

 

Gary - Thanks

 

we can try that tonight -

 

We have a double pole isolator switch - so no issues there

 

cheers

 

Innisfree...

 

Interesting - without re reading / trawling through the manual ( of which i only understand a few words.. eg contents, power positive ...)

 

that sort of makes some sense...

 

Now I have to consult with SWMBO (she's more the expert than me)

 

but would be interested in how you configured your arrangement as sitting here with my butty - I'm not sure where a manual switch would go..

 

and how you checked tested it prior to the fix...

 

oh the joys of it all..

 

 

 

 

Some times I sit and wonder and some times I just sit..........

[RobinJ]

and makes me wonder - the RCD is linked with neutral and earth to ensure that they cut should any positive come into the contact / wiring anywhere etc.

 

We did that based on what we understood to be the appropriate method - I will check that later with a meter to see if there are any stray "volts etc"

The neutral and earth should only be linked for on board or portable supllies, they should be kept separate when using a landline, otherwise stray earth currents can cause problems!

People tend not to want to modify the wiring on inverters and generators, but that is the safest way, if instead of simply swapping plugs, you have siwthcing circuits, then these should take care of the earthing.

[nb Innisfree]

Gary - Thanks

 

we can try that tonight -

 

We have a double pole isolator switch - so no issues there

 

cheers

 

Innisfree...

 

Interesting - without re reading / trawling through the manual ( of which i only understand a few words.. eg contents, power positive ...)

 

that sort of makes some sense...

 

Now I have to consult with SWMBO (she's more the expert than me)

 

but would be interested in how you configured your arrangement as sitting here with my butty - I'm not sure where a manual switch would go..

 

and how you checked tested it prior to the fix...

 

oh the joys of it all..

 

 

 

 

Some times I sit and wonder and some times I just sit..........

 

I located a 230v 10A light switch between Victron output and RCD consumer unit, connects/disconnects neutral and earth. Checked Victron beforehand by using a plug in RCD tester when on inverter power only, and not on shorepower. If not disconnected when on shorepower, shorepower RCD will trip due to this. Only prob with manual switch is if you forget to reconnect when off shorepower there will be no RCD protection, tho on the other hand there will only be 110v on live and neutral respectively, which could be argued is more reliable than RCD unless of course you grabbed L and N together! but then again RCD may not operate in this scenario. I have thought of installing a relay instead of switch to make N/E bond automatic.

[WotEver]

I have thought of installing a relay instead of switch to make N/E bond automatic.

 

Sounds like an excellent idea to me

[Strads]

Chaps

 

Appreciated the suggestions.

 

being non techy some may take us a while to fathom out and test

 

as didnt follow the 110 v bit ( did you mean 230?)

 

 

Per Garys suggestion disconnected the green plug and there was no difference..

 

so suspect either either a short (as yet not visually detected in the control wiring box) or??

 

As the rest of teh electrics seem to be fine re the land line distributor box that is also a puzzle and leave the Spur to the cooker as the main culprit

 

advise on "relays" that switch to proect the boat rcd landline rcd details would be appreciated..

 

cheers

[RobinJ]

... as didnt follow the 110 v bit ( did you mean 230?)

This is in relation to things like inverters where the live and neutral (relatively speaking) are at -110V and +110V, so in theory exposure to 'live' wire and earth is at lower potential (as against 220V). Of course exposure between 'live' wires is still at 220V!

[Gary Peacock]

Try disconnecting the circulation pump that would be my next favourite.

[WotEver]

advise on "relays" that switch to proect the boat rcd landline rcd details would be appreciated..

 

Hi,

 

For a general understanding of the best way(s) to wire up your AC, have a read of Gibbo's advice here.

 

And before you go strapping your inverter's Neutral to Earth, take a look at this thread. In particular, Post #7. Unless of course, the manual for the Inverter tells you it's already done and/or it's safe to do so.

 

T

[nb Innisfree]

Chaps

 

Appreciated the suggestions.

 

being non techy some may take us a while to fathom out and test

 

as didnt follow the 110 v bit ( did you mean 230?)

 

 

Per Garys suggestion disconnected the green plug and there was no difference..ef

 

so suspect either either a short (as yet not visually detected in the control wiring box) or??

 

As the rest of teh electrics seem to be fine re the land line distributor box that is also a puzzle and leave the Spur to the cooker as the main culprit

 

advise on "relays" that switch to proect the boat rcd landline rcd details would be appreciated..

 

cheers

 

My suggestion of a relay was to relace a manual N/E switch, the actuating coil would be energised by shore power power thereby breaking the N/E connection, disconnect shorepower and relay will de-energise and re-connect N/E. To double check that your Victron is ok to bond earth to neutral, contact Victron's help line to confirm. Though it is the same model as mine and should be ok a phone call would not hurt.

 

You should check your RCD by plugging a tester in a socket with shorepower disconnected. This will indicate either RCD is faulty (assuming E/N is bonded) or whether Victron has auto N/E bond or not, if RCD doesn't trip then there is no N/E bond.

 

RCD needs N/E connection to function.

 

The worse that can happen if Victron is manually E/N bonded and you connect to shorepower is the shorepower RCD will prob trip.

[Gary Peacock]

If the Inverter/Charger is a new one it will have a ground relay that is used by default. (A good clue is it will have a sticker on it saying VE Bus enabled. I think all the Multiplus range had ground relays but the older straight Multi's didn't)

[nb Innisfree]

If the Inverter/Charger is a new one it will have a ground relay that is used by default. (A good clue is it will have a sticker on it saying VE Bus enabled. I think all the Multiplus range had ground relays but the older straight Multi's didn't)

 

Our 24/300/70 Multiplus doesn't have a ground relay, looking at their specs online there is no mention of it but it says the 1.6KW Multiplus does have it.

[Gary Peacock]

That could well be correct Victron did a bit tinkering with specs in 2003 and again 2007/8 when VE-bus came in, at both times numbers of discounted older versions found there way into the swindlers hands and were not always sold under the label they should have been.

[nb Innisfree]

That could well be correct Victron did a bit tinkering with specs in 2003 and again 2007/8 when VE-bus came in, at both times numbers of discounted older versions found there way into the swindlers hands and were not always sold under the label they should have been.

 

To be fair to Victron they have offered to update ours free of charge if we take it to them

[Gary Peacock]

To be fair to Victron they have offered to update ours free of charge if we take it to them

 

Victron tend to very good in that way and have a lot of pride in their products new and old, they are a very engineering and support orientated company with a surprisingly small sales and marketing department.

[Strads]

Again appreciate the comments -

 

Our invertor is @ 5 yars old (along with the boat) so suggest an earlier version as described

 

guess we will have an interesting w/e with the meter and wet fingers... following the suggestions to elininate potential issues ..

 

 

have a good one!

[Strads]

Gary / Innisfree et al

 

many thanks for the hints/tips

 

SWMBO made further checks and refined the wiring into th eocntrol box to insur ethat no stray strands were shorting and its all systems go now and running fine..

 

She is a happy (warm) lady..

[Gary Peacock]

Glad it's sorted, they are a good bit of kit those Heritage cookers.