Auto changeover relay for inverter

[Techno]

Fuse and holder from china £6.99

 

[Reallyretired]

Fuse and holder from china £6.99

Thats very good. The fuses alone are £15 from our local car audio shop. (hard to find anywhere else but they are used in those enormous subwoofers the kids have in their bangers.)

 

[Techno]

Sorry I seem to have not included that the relay is over the counter at RS components or online, easy to create an account! Part number is in the picture at the start of the thread.
I will be fitting this on our new van Robbie Rapido too in the near future

 

[Techno]

Well done Haganap
Paul has grasped the concept and is having a go

 

[dottyju]

I notice in the photo's that it appears the relay coil is fed straight from the incomming EHU mains ?
If the relay coil goes faulty when on EHU the coil could easily overheat and cause a fire.
For safety this needs an appropreate ( suggest glass 240v 160mA fuse ) in series with the coil live feed !

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[eddie]

Betcha glad you started this

The supply (mains) will be incoming protected by a RCCD. The load (inverter) should will not have protection. I agree that there is overload protection but those small units are designed to have a single appliance plugged straight into them, not have multiple plugs and metres of additional wiring.

If you check the installation notes for larger inverters, that are designed to be in series with your mains/sockets a RRCD is called for.

Lovely neat installation:thumb: by the way and well explained for people. As your using a small inverter, I would recommend (as you probably have) using the incoming main to energise the contacts and use the limited power of the inverter on the N/C contacts.

The way the you have used your in line connectors is clever as you can unplug your switch from the system should it go wrong and the "hot" wires are enclosed on the existing "ring" and out put.

Cheers

Eddie

 

[Techno]

Thanks Eddie

Re the coil overheating
The very nature of the coil renders it incapable of carrying sufficient load to overheat it would simply go open circuit like a fuse would. Also it is practically potted in its own enclosure and then in a further enclosure

 

[Techno]

Eddie I appreciate what your'e saying about metres and metres of extra cable and RCD protection. However mine is not strewn around outside or across floors or indeed anywhere where it could be subject to mechanical damage and earth leakage. It is all either fixed or inaccessible and overload protection is afforded by the 10 amp fuse in the 13amp plug going to my relay.
The actual length of cable is barely longer than that that is found on most portable appliances.

Cheers

 

[eddie]

Eddie I appreciate what your'e saying about metres and metres of extra cable and RCD protection. However mine is not strewn around outside or across floors or indeed anywhere where it could be subject to mechanical damage and earth leakage. It is all either fixed or inaccessible and overload protection is afforded by the 10 amp fuse in the 13amp plug going to my relay.
The actual length of cable is barely longer than that that is found on most portable appliances.

Cheers

Oh I agree that in practice it will be fine. I am simply protecting you, in as much that if someone followed your information and electrocuted themselves, in this wonderful culture we live in some one would look to sue

If you look at the instructions on the Sterling web site, the units that are designed to have an appliance plugged in using a 13amp plug show the inverter connected to the battery and the appliance plugged in. Link Removed

The units that are wired in, in series show a the inverter going through the RCD. The same advice is given to us from Mastervolt, Victron and Dometic

Link Removed

I personally prefer to give the inverter output it's own RCD to avoid confusion. For smaller inverters we have seen the in line types of device used, such as you would use on an extension lead for garden appliance.

Imagine knocking a kettle into a bowl of washing up water for example. When on mains the RCD would (should) trip fast enough to avoid electrocution. When the power is from the inverter no such protection is employed. Hence the manufacturers showing the inclusion when wired in:thumb:

 

[Techno]

It is possible to do that in many households that still have no RCD protection.
There has to be consideration of likely hood and I certainly wouldn't use and electric kettle on inverter with a sink full of water. Most motorhome sinks you struggle to get a cup in never mind a kettle

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[Techno]

For the have a go heroes !
[ame="http://www.amazon.co.uk/gp/product/B000RZDNZM/ref=pd_lpo_k2_dp_sr_3?pf_rd_p=103612307&pf_rd_s=lpo-top-stripe&pf_rd_t=201&pf_rd_i=B005OKG8CA&pf_rd_m=A3P5ROKL5A1OLE&pf_rd_r=10HEVAYCJNTSZBSQ12SW"]Masterplug ARCDKG Safety RCD Adaptor: Amazon.co.uk: DIY & Tools[/ame]

 

[eddie]

It is possible to do that in many households that still have no RCD protection.
There has to be consideration of likely hood and I certainly wouldn't use and electric kettle on inverter with a sink full of water. Most motorhome sinks you struggle to get a cup in never mind a kettle

That's why we struggle to get a cup of tea out of some of our customers then

Eddie

 

[Techno]

It may just be they don't want you to use their toilet

 

[olley]

Why make it so complicated? I just fitted a 16amp socket to the inverters outlet, and plug my EHU lead straight into it, simple. cheap and foolproof.

Ian

 

[Techno]

It's not the least bit complicated and I've no leads to get out I just switch it on when I want my microwave.

It's only complicated to those who don't understand it and I would not expect them to even attempt it by their very nature.

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[rainbow chasers]

what's an INERTER please

I was waiting for that comment! Scroll down , I said to myself, there has to be one somewhere.x
x
x
An inerter is actually an electricians cable, specially designed to make things look more complicated. It does nothing, serves no purpose, and doesn't need to be there - it's inert! x
x
x
Oh, and I am not blowing kisses here, my keyboard has gone wonky!

 

[haganap]

Why make it so complicated? I just fitted a 16amp socket to the inverters outlet, and plug my EHU lead straight into it, simple. cheap and foolproof.

Ian

Are you then not using the Inverter to charge your batteries?



Not really that difficult Ian. I followed the instructions to a letter with a bit of help from Andy and it works a treat.......

All fused as well,

 

[olley]

I turn the charger off haggers. If your on EHU you don't need the inverter, when I unplug the EHU I plug into the inverter, walk in the van and turn the charger off and turn the inverter on with its remote switch, now all my circuits 110 and 230v are live, fused and protected by the existing RCCD.

Ian

 

[Techno]

Better hope it's not chuckin it down

 

[haganap]

I turn the charger off haggers. If your on EHU you don't need the inverter, when I unplug the EHU I plug into the inverter, walk in the van and turn the charger off and turn the inverter on with its remote switch, now all my circuits 110 and 230v are live, fused and protected by the existing RCCD.

Ian

God Ian, and you said Andy's method was complicated


If it means more than pressing my remote control mate it's hard work.:thumb:

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[Reallyretired]

Just a question. Would an ordinary RCD work on an inverter output, as there is no earth?

 

[Techno]

You earth it to the vehicle chassis (or the same earth terminal used by the hook up lead) and the inverter earth terminal

 

[olley]

An RCCD measures the difference between the positive and negative supplies, unless you are using your chassis as a negative return, which I would think unlikely you wouldn't connect it to your chassis.

Ian

PS. sorry that's not very clear. If for example 10amps is flowing through the positive supply, 10amps should be flowing back through the negative, if their is more than usually a 30ma difference the RCCD will trip.

 

[Techno]

Live Neutral and reference earth. It's nothing to do with DC

 

[Techno]

Again IAN it is live and neutral not pos and neg and you require an earth
Link Removed

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[Reallyretired]

As I understand it an RCD measures the difference in current between line and neutral and trips if these are different by more than (usually) 30Ma. The difference being assumed to be due to leakage.

In my opinion any leakage is likely to be to earth, and I believe most inverters connect earth to neutral. If I am right, and I would be pleased if someone could tell me I am wrong, then a leak to earth would not be detected as the leaked current would still appear in the neutral line.
On second thoughts because the connection between line and neutral is before the rcd and any leakage will be after it, perhaps it will work.
I am not an electrician, so hopefully someone knows the answer for sure.

 

[Techno]

As per Eddies link earlier
Link Removed

 

[Techno]

My earth continuity is maintained here from the first post so it doesn't matter what position the relay is in. So when my relay is plugged into my inverter it earths the inverter through this common connection also. So mine would work fine with a RCD plug in adaptor if I believed I required it.

 

[olley]

Again IAN it is live and neutral not pos and neg and you require an earth

Sorry tecno I am guilty of terminological inexactitude I always refer to 230v AC as as pos and neg, although its is as you say correctly "live and neutral."

Ian

 

[Techno]

It's OK lol
One of the most important issues of the wiring regulations is to make sure everyone uses the correct terms so there is no confusion :thumb:

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