1.5mm or 2.5mm hook up cables?

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Tony68000

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Are there any issues using 16amp 1.5mm cables for electric hookups?

I'm sure I've read somewhere that they aren't acceptable, but the ones I'm looking at are BS rated and 16amps, so is there a problem or not?

Thanks.
 
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Some great information here. Thank you everyone.

I'm going to purchase a short 14m roll at 1.5mm rated at 16amps, and will probably look at a 25m 2.5mm the day after I need something longer :ROFLMAO:

I will uncoil! I'm already conscious of this requirement, I never run an extension lead to the garden without uncoiling in full. I'm the sort of person who takes peoples plugs apart to ensure they are wired correctly. My horror story is finding a lawnmower lead wired the wrong way - live pins! Goodness knows how someone didn't die. I take great pride in trying to be safe as possible so all your advice and suggestions will be taken on board.

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RustyRuss said:
EDIT, just had another look at the data sheet below, if the ambient temperature the cable experiences is 40 degrees C, so for example at the side of the MoHo in full sunlight on hard standing with no cooling breeze, the de-rating factor is 0.82, so 16amps max capacity x 0.82 = 13.12amps max capacity, at 50degrees C, so for example on a campsite on hard standing in full sunlight in the South of France or Spain the de-rating factor is 0.41, so that’s 16amps x 0.41 = 6.56amps max capacity. The 2.5mm 3 core’s max capacity is 25amps, 25 x 0.41 = 10.25amps!!
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If you have to derate for high temperatures, does that mean you can uprate for low temperatures? So that your 1.5mm2 cable laid over snow is more than OK for 16A when using the heating in winter?
 
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Bessy765 said:
Difference between 1.5 and 2.5 pennies. Loss of life priceless.
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Somebody who clearly knows little about electricity, modern protection systems or how electrical cables are rated.

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I've used the same 1.5mm blue arctic cable for 20+ years now, and never had a problem. I have one 10m and one 15m cable. I do know and fully understand all the issues involved. It isn't about money. Other factors come into play too, weight for instance, and ease of use. The highest current user in my setup is the heating, which implies that outside it is cooler, so better cable cooling. Thus Spain in summer would be no issue, apart from it is usually too hot for me to ever want to be there!
 
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I think that, even if 1.5mm2 is a bit under-specified, going up to 2.5mm2 is a bit over-specified for a 16A hookup. The ideal would be 2.0mm2, with a voltage drop of 3% at 16A. However it's a bit difficult to get hold of 3-core 2.0mm2 cable, don't know why.
 
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If you're only a modest consumer of electricity (not heating) 1.5mm2 should be OK. You could always use a lower rated breaker inside the van to protect the wire.
It depends where you go as to what length to get but, in the UK, pitches are usually within 25m of a hook-up point and often much less. If you want to be neat and route your wire indirectly, you will need the full 25m occasionally.
Get "arctic" wire. It's so much easier to gather up and manage (even for 2.5mm2).
Connections are a weak point (and outlawed on some sites), so I wouldn't split 25m into 10m+15m. With arctic wire, it's not so ungainly, anyway.

Be aware of the need to respect 'leccy but don't become afraid of it.
I've seen the 'rules' being broken many times but not yet seen anyone suffer.
 
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I originally had 2 x 25m 2.5mm2. Split one down to 8m which lives at home to cool the fridge prior to departure. On the rare occasions I use a hookup I deploy the remaining 17m cable until I find it's a metre short and have to get the other one out. If both are required I just connect the usual male/female sockets inside a Sainsburys bag.( other makes are available)
 
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Am I the only person that carries a 4mm cable to avoid voltage drop over the length of the cable?

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RustyRuss said:
it’s protected by a 10amp MCB so the very most current it will experience before the MCB trips is 1.2 x 10amps = 12amps. A 16amp MCB will trip/break/disconnect at 1.2 x 16amps = 19.2 amps, 20% more than the cable is designed to cope with.
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In reality, you should be protecting against live-neutral shorts using the instantaneous part of the MCB curve, not relying on the slow acting thermal protection which is intended to protect against long term overloading, not short circuit. For a Type B MCB, that is 5x at worst case, so a 16A cable will need to draw 80A to guarantee an instantaneous break. That requires total loop impedence to be low enough for a short to invoke that much current. From a safety perspective, this is the limiting factor on cable length. The voltage drop is more limiting, but is typically more of a functional/efficiency limit than a safety one.
 
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TheBig1 said:
Am I the only person that carries a 4mm cable to avoid voltage drop over the length of the cable?
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No, all Americans do as they only have 110v over there.

Its been explained above, voltage drop is rarely if ever a problem. Heaters may heat a fraction less but never noticeable. Modern electronic equipment uses switch mode power supplies which are very tolerant of the actual voltage.

In all the years I've been camping/caravanning/ motorhoming I've never seen anyone use 4mm cable, except of course in America.
 
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Old Gibber said:
Somebody who clearly knows little about electricity, modern protection systems or how electrical cables are rated.
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No just an Electrician of over 40 years, who has seen 1.5 m cable laying in the snow melting where it lays, also the actual ehu inlet in the side of a motorhome smoking. It’s all very well having safety protocols. But when one is running a 25 mtr 1.5 at max capacity before the trip will operate will result in problems

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RustyRuss said:
Follow this link for eland cables arctic cable. It clearly states on page 2 that 1.5mm 3 core cable has a current carrying capacity of 16amps. However as a safety conscious bod I would err on the side of caution, this it’s MAXIMUM current carrying capacity, I use 2.5mm 3 core max 25m long for 16amp EHU posts and 1.5mm 3 core only for 10amp EHU posts. I use the 1.5 when hooked up at home to my outside socket, it’s protected by a 10amp MCB so the very most current it will experience before the MCB trips is 1.2 x 10amps = 12amps. A 16amp MCB will trip/break/disconnect at 1.2 x 16amps = 19.2 amps, 20% more than the cable is designed to cope with. This is known as the MCB’s fusing factor; incidentally old fashioned fuses like you find in your 13amp plugs have a fusing factor of 2! So it’ll eventually break at 2X13amps = 26amps!! That’s 6.24KW and when you expose 1.5mm 3 core cable to that amount of current for 2-3 minutes the insulation, both inner and outer, gets so hot that it starts to melt. So it will catch fire before the fuse blows.
EDIT, just had another look at the data sheet below, if the ambient temperature the cable experiences is 40 degrees C, so for example at the side of the MoHo in full sunlight on hard standing with no cooling breeze, the de-rating factor is 0.82, so 16amps max capacity x 0.82 = 13.12amps max capacity, at 50degrees C, so for example on a campsite on hard standing in full sunlight in the South of France or Spain the de-rating factor is 0.41, so that’s 16amps x 0.41 = 6.56amps max capacity. The 2.5mm 3 core’s max capacity is 25amps, 25 x 0.41 = 10.25amps!!

Sorry to get technical but electricity is so much a part of our daily lives that we can become blase about how bloody dangerous it can be!!

https://www.elandcables.com/media/38199/arctic-grade-cable-h05vv-f.pdf


Cheers and stay safe boys n girls!!


Russ
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But unless you have fitted hab Aircon who is going to use much power in the south of France in the heat. We have no kettle hairdryer tongs etc the load would be the fridge and occasionally water heater. It won't really affect us as we generally come back from a holiday somewhere like that with the cable still in the bag but I think we could probably very easily manage with 1.5 mm cable. Same with uncoiling the cable I always do it but at the current we draw I suspect it won't make a difference
 
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Bessy765 said:
No just an Electrician of over 40 years, who has seen 1.5 m cable laying in the snow melting where it lays, also the actual ehu inlet in the side of a motorhome smoking. It’s all very well having safety protocols. But when one is running a 25 mtr 1.5 at max capacity before the trip will operate will result in problems
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If the EHU inlet is smoking then this would suggest a poor connection at the inlet rather than the lead itself.

If you have seen cable laying in the snow melting where it lays then it suggests something else is the problem here. If the snow is well below freezing then this suggests most likely a current overload. 1.5mm arctic cable is rated at 16amps at 30 degrees C. As any decent electrician knows the limiting factor on any cable's current capacity is the ambient temperature, and there are charts for reduced capacity in trunking for instance.

However, if the snow is close to melting point then it is quite likely the normal temperature rise in the cable due to its resistance will cause the snow to melt when running close to its current limit. Not a cause for concern, cables are desogned to handle such a current rise.

I'm still bemused at the likelyhood of loss of life due to this though, though I've never seen much about it in the news in the last few years, and one would have thought that such a significant loss of life would have made the day for a few newspapers.
 
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Unfortunately the latest version of the Regulations (ver 18) now say the only cable to meet the rules is 2.5mm orange cable. More importantly it now says there must not be any joints between the supply pedestal and the van inlet. So even if we have a waterproof box to cover the joint, a Warden can say you are not allowed to use the cable. This is probably just to stop people putting splitters in the cable and over loading the supply
However I still use my 10m and 15m with a waterproof cover as was allowed in the previous regs

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Always use 2.5 mm
Won't cost you that much more but far safer.
I know there are lots out there that will say 1.5 mm is OK, yes it is but buy the best and stay safe.

Don't leave you cable on the reel or coiled up this acts like a resistance creating a magnetic field generating heat and can cause a fire. Always run your cable up and down beside the van or get yourself a shorter lead.
 
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Two on Tour said:
We carry a 1.5mm EHU cable as we are rarely on EHU, and when we are the only 240v we use is the water heater at 6.5amps, the battery chargers which draws less than an amp and the fridge which draws bugger all, so well with the rated capacity for cable.
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It isn't about the load you are putting on the cable. It is about the "protection" i.e. the supply has a circuit breaker at 16Amps so that is what protects your cable against current greater than the cable can stand. Basically your cable should be capable of carrying the full load allowed through the supply circuit breaker. This means that under fault conditions the breaker will open before the cable fails.
 
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RobbieBobby said:
It isn't about the load you are putting on the cable. It is about the "protection" i.e. the supply has a circuit breaker at 16Amps so that is what protects your cable against current greater than the cable can stand. Basically your cable should be capable of carrying the full load allowed through the supply circuit breaker. This means that under fault conditions the breaker will open before the cable fails.
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You seem working on the basis that a 1.5mm2 cable rated at 16 amps, will fail at a 16 amp load and you have failed to account for the Factors of safety (FoS) that are always built into design codes on cabling.
 
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Two on Tour said:
You seem working on the basis that a 1.5mm2 cable rated at 16 amps, will fail at a 16 amp load and you have failed to account for the Factors of safety (FoS) that are always built into design codes on cabling.
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I'm not working on any basis except the basic principle of staged protection. Factors of safety are just that, safety. They are not there to be eaten into, but to provide protection for "variabilities". So everything downstream of the 16A breaker should be capable of carrying 16A to the point of the next protection device (which will be lower than 16A). Think about it like this: 16A circuit breaker feeds 16A rated cable which feeds the consumer unit in the vehicle. In that consumer unit there are various breakers for the individual circuits. Lets say there is a 5A breaker for a circuit. Now the cabling for that circuit only needs to be rated at 5A. If you connected something which pulled more than 5A then the 5A breaker would trip to protect the cable from overload. That's the reason that a table lamp at home should have a 3A fuse in the plug - because the (thin) cable to the lamp is only rated at 3A. If you put a 13A fuse in the plug then the cable is not protected.
 
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Tony68000 said:
If you could only carry one, what length would you get? At this point, until I have a requirement I don’t want to be buying 2. 15m or 25m?
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25 metre 2.5mm. This covers all options. I've just today connected the cable to my new van and it used almost all of 25metres. IMHO anything less is false economy - especially 2.5mm V 1.5mm. Should always be 2.5mm to be absolutely on the safe side.

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