Me on the Motorhome Matt Podcast

[edina]

Can o worms you’ve opened here @Admin

 

[trevskoda]

Can o worms you’ve opened here @Admin

Well he wont wiggle out of it, and no you wont be getting them for bait.

 

[barryd]

Merl take another look at the video, its at the end after the main discussion on it I think. The 3 pin socket Matt uses to connect his ehu socket at his house could give the same fault as the adapter on the power bank from what they said. To make this safe he is going to install a ground spike at the outside socket, this in effect then becomes the same as an on site EHU socket. You need to have another look as its a bit beyond me but from what I am taking fro it you haven't quite understood what they are saying.

Merls explanation made sense to me as its what I thought initially but I never watched the full video. Here it is cued at the exact point where the "presenter" (not Phil or the other expert) makes the claim about the house socket. I thought though they said at the beginning that normal 240v sockets were already earthed and the point was floating powerpacks were not.

 

[colinm]

This is why our 'van shed', has a earthing point directly connected to the socket used for EHU.

 

[MERL]

Merls explanation made sense to me as its what I thought initially but I never watched the full video. Here it is cued at the exact point where the "presenter" (not Phil or the other expert) makes the claim about the house socket. I thought though they said at the beginning that normal 240v sockets were already earthed and the point was floating powerpacks were not.

Yep sorry my bad Barry. Campsites in the UK use a different set-up for earthing pitches called aTT system, I'd forgotten about that.
It's perfectly true that if the neutral in your EHU lead becomes disconnected while using the PME house wiring then the the whole van can become live via a route through an appliance. This is mitigated by using a TT system and connecting the van it's self to planet earth via an earth rod. A TT system isn't perfect because if the earth cable in your EHU becomes detached you no longer have this protection, also the TT system relies entirely upon RCD protection because there's a poor route through the earth circuit for over current protection unlike in a PME system. For this reason you MUST check your RCD operation regularly BUT couldn't you simply use a PME system in your MH and regularly check the sockets with a socket tester instead?
In the UK we use PME, in some countries like Japan and several other parts of the world they use a floating system (IT) just like you get from an inverter/power pack. Both systems are safe until something goes wrong, both systems get dangerous when certain things go wrong, the fact that each system becomes dangerous under DIFFERENT sets of fault scenarios leads to a debate about what is safe/safest and what is not.
It's complicated and nothing is 100% perfect.

 

[Robmac]

What I don't understand is just how lethal 240V is (I know it's down to Current).

But over the years I've had many 240V shocks and although it's not very pleasant I didn't suffer any serious harm, yet my mate had his first and sadly his last shock from a lawn mower (corded on wet grass).

I appreciate that the lawn mower would be high current in use, but he was a big strong man. When I was about 5 my brother dared me to put my hands around the bars of an old fashioned electric heater 'to see how long it would take to get hot'. I grabbed the bars, he switched it on and I was thrown the length of the room. I would have thought that was high current and I was a runt of a child at the time.

 

[MERL]

What I don't understand is just how lethal 240V is (I know it's down to Current).

But over the years I've had many 240V shocks and although it's not very pleasant I didn't suffer any serious harm, yet my mate had his first and sadly his last shock from a lawn mower (corded on wet grass).

I appreciate that the lawn mower would be high current in use, but he was a big strong man. When I was about 5 my brother dared me to put my hands around the bars of an old fashioned electric heater 'to see how long it would take to get hot'. I grabbed the bars, he switched it on and I was thrown the length of the room. I would have thought that was high current and I was a runt of a child at the time.

It doesn't take much current to kill a person Rob, a fraction of an amp will do it so any domestic circuit will do the trick. Most times you've had a shock the route of the power will be from live through you and then back to the local transformer via planet earth, the resistance of planet earth reduces the current flow somewhat and the 'belt' is often quite mild. Get between live and system earth.or neutral (which we know are the same thing in a PME system) and the current flow and belt are usually higher. Put 2 fingers of the same hand across live and neutral and the current will flow through your hand, put the fingers of left and right hands across live and neutral and you now have current flowing across your heart which effectively stops it.
The 'throwing you across the room' that we talk about isn't the actual force of the electricity doing the work, the current flow causes muscles to violently contract and this is what causes the jumping or pulling. It's this automatic pulling action that protects us nearly every time we get a shock because our arm muscles tighten and we pull away from the power.
Working on electrics up a metal ladder is particularly dangerous because the metal ladder provides a path to earth should you touch something live, the contraction of your leg muscles will normally throw you from the ladder. Hence glass fibre ladders in the industry.
A guy I worked with died when he accidentally came into contact with a live feed to an electric shower in a roof space, he was working tight in the eaves and consequently lying down and had nowhere to fall away from the power.

 

[Robmac]

It doesn't take much current to kill a person Rob, a fraction of an amp will do it so any domestic circuit will do the trick. Most times you've had a shock the route of the power will be from live through you and then back to the local transformer via planet earth, the resistance of planet earth reduces the current flow somewhat and the 'belt' is often quite mild. Get between live and system earth.or neutral (which we know are the same thing in a PME system) and the current flow and belt are usually higher. Put 2 fingers of the same hand across live and neutral and the current will flow through your hand, put the fingers of left and right hands across live and neutral and you now have current flowing across your heart which effectively stops it.
The 'throwing you across the room' that we talk about isn't the actual force of the electricity doing the work, the current flow causes muscles to violently contract and this is what causes the jumping or pulling. It's this automatic pulling action that protects us nearly every time we get a shock because our arm muscles tighten and we pull away from the power.
Working on electrics up a metal ladder is particularly dangerous because the metal ladder provides a path to earth should you touch something live, the contraction of your leg muscles will normally throw you from the ladder. Hence glass fibre ladders in the industry.
A guy I worked with died when he accidentally came into contact with a live feed to an electric shower in a roof space, he was working tight in the eaves and consequently lying down and had nowhere to fall away from the power.

Another one I had at a young age Merl was standing on top of a copper tank with bare feet in an airing cupboard changing a light bulb, the bruises from the fall were worse than the shock. I've also had a few from various dubiously wired microphones doing a mobile disco in the 70's.

There was a strange aspect to my mates story with the lawnmower. His wife witnessed it happening and ran out to help him, when she touched him she got a shock herself. She was told at the time that it would be 'residual electricity stored inside the body from the initial shock' but I know that this cannot happen. Maybe the current was still going through him and a fuse blew and cut it off as she touched him? or maybe the shock came through the wet grass as she knelt next to him? It baffled us all at the time.

 

[molly 2]

I bought a bluetti power station and solar when I plugged it into hook up I noticed the polarity light was illuminated on my sargent 328 unit ,I phoned Hampshire genarators my supplier, I was it was told the earth was wired differently and was normal and it was OK to plug into hook up socket , l have been plugging in my power station for about a year no problems, , but I am confident that admin is right ???

 

[trevskoda]

Im sticking to 12v and playing safe.
Try a shock from a outboard egn sys at 40/50 thu volts, litle current but one hell of a jolt and can kill.

 

[MERL]

His wife witnessed it happening and ran out to help him, when she touched him she got a shock herself

That'll happen, he was live so touching him would probably cause his wife to be shocked too. I recall watching a safety video about what to do if you witness someone getting electrocuted, you DON'T get hold of them to pull them off the power, you get something like a sweeping brush and push them off or pull the cable away, if nothing is available you take a run up and shoulder charge them off!

 

[Robmac]

That'll happen, he was live so touching him would probably cause his wife to be shocked too. I recall watching a safety video about what to do if you witness someone getting electrocuted, you DON'T get hold of them to pull them off the power, you get something like a sweeping brush and push them off or pull the cable away, if nothing is available you take a run up and shoulder charge them off!

I thought he must still be 'live' Merl. She was unharmed though, I believe he ran over the cable with the mower which caused the shock.

 

[barryd]

I am afraid I'm am none the wiser. Is it safe to plug your van into an ordinary home socket or not?

It sounds to me like it's not if your blue neutral plug somehow comes loose and you have two devices fail at the same time in the van but I thought the vans own board delt with all that and surely if your neutral connection failed in the hookup lead or plug it would cut the power to the van anyway.

 

[Mr and Mrs Tupcox]

I was straight on to admin.
As I have inverter which I connect to our 240v hook up point
We only run one thing at a time.
And we have A Type rcd so I think we good to go.

 

[Nabsim]

I am afraid I'm am none the wiser. Is it safe to plug your van into an ordinary home socket or not?

It sounds to me like it's not if your blue neutral plug somehow comes loose and you have two devices fail at the same time in the van but I thought the vans own board delt with all that and surely if your neutral connection failed in the hookup lead or plug it would cut the power to the van anyway.

It does say about the 240V protection in a van Barry, you need to watch it properly if you haven't yet. One type of RCB(?) won't protect you if it goes wrong using the power bank (or home socket ehu) and while the other should, it won't always.

I may be wrong so get Phil or someone else to say but I take away from it you are perfectly safe using the power bank with devices plugged directly into it but dot go through the EHU socket, if you want to charge batteries plug the charger into the power bank directly. With home EHU 3 pin plus using adapter you should have an earth spike fitted to the 3 pin socket. You need expert advice though as its beyond me and its only what I am getting from it all so no saying I m right or not.

 

[MERL]

Is it safe to plug your van into an ordinary home socket or not?

It's perfectly safe until you lose the neutral connection. It's then still safe until you power something from the mains within the van, at that point the van probably becomes live.
The house RCD MAY trip but it may not.
If it doesn't trip then anyone inside the van is still safe because they are floating at the same potential as the vehicle (like a bird sitting on a power line)
If you stand on the ground outside the van and touch a metal part of the van then you'll probably get a shock (depending on what you're standing on and how wet the ground is and what shoes you're wearing) At that point you'll shout "Oh you ****er!" and pull your hand away quickly, if you don't then the rcd inside the house should trip and save you from being killed to death.
You now have to decide if that's safe.
Alternatively you can add your own earh spike and connect it to the van somehow but technically when you do that you should remove the earth connection from the EHU lead. You've now removed one earth source and replaced it with another, If you forget to connect the earth rod or the connection becomes detached for whatever reason you're arguably in a worse scenario because you now have NO earth at all at your van.
You now have to decide if that's safe/safer than the 1st scenario.
I'm guessing but I strongly suspect that driving your motorhome too and from your destination is statistically way more likely to kill you than plugging your van into EHU from the house. Maybe just sell the MH and stay in bed mate.

 

[barryd]

It's perfectly safe until you lose the neutral connection. It's then still safe until you power something from the mains within the van, at that point the van probably becomes live.
The house RCD MAY trip but it may not.
If it doesn't trip then anyone inside the van is still safe because they are floating at the same potential as the vehicle (like a bird sitting on a power line)
If you stand on the ground outside the van and touch a metal part of the van then you'll probably get a shock (depending on what you're standing on and how wet the ground is and what shoes you're wearing) At that point you'll shout "Oh you ****er!" and pull your hand away quickly, if you don't then the rcd inside the house should trip and save you from being killed to death.
You now have to decide if that's safe.
Alternatively you can add your own earh spike and connect it to the van somehow but technically when you do that you should remove the earth connection from the EHU lead. You've now removed one earth source and replaced it with another, If you forget to connect the earth rod or the connection becomes detached for whatever reason you're arguably in a worse scenario because you now have NO earth at all at your van.
You now have to decide if that's safe/safer than the 1st scenario.
I'm guessing but I strongly suspect that driving your motorhome too and from your destination is statistically way more likely to kill you than plugging your van into EHU from the house. Maybe just sell the MH and stay in bed mate.

I've decided to forget about it, buy a pie and get pissed instead.

 

[MERL]

I've decided to forget about it, buy a pie and get pissed instead.

What kind of pie? Dont attempt to warm it up in the van microwave whilst on the drive and on EHU. Surely you know about the risks from cholesterol too? Just get pissed mate.....hold on.....isn't achohol pretty bad as well?

 

[colinm]

I bought a bluetti power station and solar when I plugged it into hook up I noticed the polarity light was illuminated on my sargent 328 unit ,I phoned Hampshire genarators my supplier, I was it was told the earth was wired differently and was normal and it was OK to plug into hook up socket , l have been plugging in my power station for about a year no problems, , but I am confident that admin is right ???

This is not about what happens if everything is ok, it's about what happens if there is a fault in your equipment.
The best analogy I can think of is a seatbelt, most people will have no need of one, and I guess like many on here as a child and young adult I was ferried about in cars with no seat belts, and when I first started driving never had a seatbelt, and I'm still here to tell the tale, but nowadays I 'clunk click' every trip.

 

[edina]

When I installed my multiplus, I'm sure there was something about it changing the earthing system to suit the supply. Would this overcome the probs mentioned in the video?