1.5mm or 2.5mm hook up cables?

[Tony68000]

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.

 

[AndyT4]

Electrician for 45years, it's simple, the smaller the cable the warmer it gets, the longer it is the HOTTER it gets, BS7671 will explain it all. Seen too many wound up cable reels on site melt.

 

[cmcardle75]

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.

Whilst the resulting advice is the same (always unreel), the reason is nothing to do with magnetic fields (aka inductance). It is purely about having heat producing cables in close proximity with little chance for heat to escape. This is because the neutral and live are in close proximity within the cable and their inductances cancel each other out.

 

[Raul]

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.

Your cable does not have to be able to carry the full 16a downstream. You can have a 1,5mm and fused at 10a. That 10a will protect your cable. The Borland 16a protects upstream, not downstream, it does not care what you running, but it will limit you at 16a.

 

[Clive and Sally]

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.

I use H07RN-F rubber cable rather than artic or the normal orange cable as it's a lot more flexible & can carry more current. The 1.5mm 3 core is rated at 23amps at 30°C. I carry a 10m & a 15m one both terminated in IP65 16amp connectors so I can join them together if I need the full 25m.

^{_{Subscribers  do not see these advertisements}}

 

[Midnightflyer]

Whilst the resulting advice is the same (always unreel), the reason is nothing to do with magnetic fields (aka inductance). It is purely about having heat producing cables in close proximity with little chance for heat to escape. This is because the neutral and live are in close proximity within the cable and their inductances cancel each other out.

That's not what I was told by a lecturer in Electrical Engineering. He said if you coil any wire like a transformer or the coils in a motor winding the tighter these windings are when an electrical current is passed through them they will generate heat and in some cases enough to melt the insulation and cause a fire.

As for the magnetic field, if you have a small amount of cable left on the reel or coiled up tight on the ground try bring a compass near to it and see what happens to the pointer. Magnetic Field! Then move the compass to the cable leading to the coil, No magnetic field to speak of.

As we both said best thing is to not leave cable coiled up when in use.

 

[Richard n Ann]

As for the magnetic field, if you have a small amount of cable left on the reel or coiled up tight on the ground try bring a compass near to it and see what happens to the pointer. Magnetic Field! Then move the compass to the cable leading to the coil, No magnetic field to speak of.

A compass is VERY sensitive and is probably being affected by the (cancelling) magnetic fields. They're quite tiny and inconsequential.

 

[cmcardle75]

That's not what I was told by a lecturer in Electrical Engineering. He said if you coil any wire like a transformer or the coils in a motor winding the tighter these windings are when an electrical current is passed through them they will generate heat and in some cases enough to melt the insulation and cause a fire.

Indeed they do, but only because they are in close proximity with no ventilation. Nothing to do with the coiling, except that is an easy way to get lots of cables in close proximity.

As for the magnetic field, if you have a small amount of cable left on the reel or coiled up tight on the ground try bring a compass near to it and see what happens to the pointer. Magnetic Field! Then move the compass to the cable leading to the coil, No magnetic field to speak of.

There will be a measurable magnetic field, but not enough to cause any trouble to a 50Hz current. This is because with the cable carrying current in both directions simultaneously, the magnetic field created by the live conductor is cancelled out by the almost (but not quite) opposite field created by the adjacent neutral conductor. There's enough difference to detect using a sensitive device like a compass, but not enough to cause any significant difference in impedence.

If you wrapped the live conductor into one coil and the neutral conductor into another, all bets are off.

 

[gerry mcg]

Why can't one join a cable using proper IP67 waterproof connectors?

Amphenol 16A 2P+E Plug 250V - Screwfix

Order online at Screwfix.com. 2P+E. 250V. 16A Compact design, excellent grip industrial plug. FREE next day delivery available, free collection in 1 minute.

www.screwfix.com

 

[RobbieBobby]

fuse cable does not have to be able to carry the full 16a downstream. You can have a 1,5mm and fused at 10a. That 10a will protect your cable. The Borland 16a protects upstream, not downstream, it does not care what you running, but it will limit you at 16a.

I'm sorry, but there is no easy way to say this other than you are wrong. Electrical protection devices protect "downstream" of the device. e.g. 100A fuse protects 100A cable feeding a fuseboard. If that fuseboard contains outgoing fuses at 10A each then each circuit can have 10A cable. One of those cables could feed a further distribution board with smaller circuits, fused at say 3A each. Now the cable in each of those circuits only needs to be rated at 3A. The example I use here doesn't refer specifically to hook-up cables. It is more a generalisation of electrical distribution. Your house is wired this way. e.g 100A fuse at the incoming meter. 100A cable from the meter to the consumer unit. The main breaker on the consumer unit may only be 63A but the cable from meter to CU must be 100A cable and not 63A. Don't take my word for all this. There are plenty of books on the subject.

^{_{Subscribers  do not see these advertisements}}

 

[ukdw]

I carry two cables one short and thick (so I presume 15mx2.5mm ) and one longer and thinner (I presume 30mx1.5mm).

So it sounds like I have the thicknesses the wrong way around,

I store them wound around the flat black things pictured earlier in the thread, and I always fully unwind them.

i almost always try the shorter one first - so sometimes have to wind it back up again before switching to the longer one.

At a caravan club site last week I had a bit of trouble with their new power bollards - I couldn't get either cable to work, and even tried directly connecting a kettle up on a short bit of male blue connector to normal socket cable.

it turned out that with the new bollards whenever you disconnect the load the circuit breaker trips and you have to reset it. The confusing thing was that it turns out that tripped or disconnected has a green indicator, whereas connected has a red indicator,

The reason this fairly long post is that I couldn't find my socket tester plug which I usually keep in the van and may have helped me diagnose what was wrong with my understanding of the circuit breakers. So I bought a new one, which has a voltage indicator meter on it too. So next time I am away I am going to test out the voltage drop figures mentioned in the earlier part of the thread with both cables individually plus connected together.

If the drop off is as much as indicated might have to change my cables around and make up a shorter thin one and a longer thick one. Whch will actually end up being better in most cases - as the thinner long one is much easier to coil back up on cold mornings than the thicker short one,

 

[Raul]

I'm sorry, but there is no easy way to say this other than you are wrong. Electrical protection devices protect "downstream" of the device. e.g. 100A fuse protects 100A cable feeding a fuseboard. If that fuseboard contains outgoing fuses at 10A each then each circuit can have 10A cable. One of those cables could feed a further distribution board with smaller circuits, fused at say 3A each. Now the cable in each of those circuits only needs to be rated at 3A. The example I use here doesn't refer specifically to hook-up cables. It is more a generalisation of electrical distribution. Your house is wired this way. e.g 100A fuse at the incoming meter. 100A cable from the meter to the consumer unit. The main breaker on the consumer unit may only be 63A but the cable from meter to CU must be 100A cable and not 63A. Don't take my word for all this. There are plenty of books on the subject.

You are absolutely right, I worded bad that post.

 

[autorouter]

So I bought a new one, which has a voltage indicator meter on it too. So next time I am away I am going to test out the voltage drop figures mentioned in the earlier part of the thread with both cables individually plus connected together.

As long as you are aware that the voltage drop depends on the amps passing through the cable at the time. A voltage tester just on the end of an unconnected cable won't register any voltage drop. It will only show up if there is a substantial load drawing several amps.

 

[autorouter]

Why can't one join a cable using proper IP67 waterproof connectors?

Because apparently some UK campsites insist that the cable can have no joins in it. Anywhere else it would be fine.

But for me the main reason is these connectors don't fit in the mains inlet of my MH. I bought some of these connectors, wired them all up, then had to swap them back to plain old IP44 ones

 

[autorouter]

As for the magnetic field, if you have a small amount of cable left on the reel or coiled up tight on the ground try bring a compass near to it and see what happens to the pointer. Magnetic Field! Then move the compass to the cable leading to the coil, No magnetic field to speak of

A compass needle is not a good method of detecting a mains current that reverses 50 times per second. It only detects steady magnetic fields. The field averages out to zero over even a fraction of a second. Was the cable reel made of steel?

To reduce the magnetic field further, you can use 4-core cable. Connect the diagonally opposite wires to the same pin, either live and neutral. This is much better at cancelling the magnetic field. This idea is mainly used to reduce hum pickup on long microphone cables and sensitive instruments.

^{_{Subscribers  do not see these advertisements}}

 

[BouncyBoatFolk]

I think your initial idea was preferable, slightly less load and volts at the end of heavy lead, thus better for the lighter duty cable.

I had a load of 110v leads kicking around, so have converted a couple of them to 240v, with correct plugs on. They are 16amps as standard, and yellow, so a bit more visible.Mechanically robust as well as intended for site use.
Mike.

 

[Richard n Ann]

I had a load of 110v leads kicking around, so have converted a couple of them to 240v, with correct plugs on. They are 16amps as standard, and yellow, so a bit more visible.Mechanically robust as well as intended for site use.
Mike.

Our orange one turned yellow in the sun anyway

 

[Midnightflyer]

I don't know why I bother to help another Funster when this form is so full of smart arses.

Don't think I will bother to give any advise in the future.

 

[cmcardle75]

I had a load of 110v leads kicking around, so have converted a couple of them to 240v, with correct plugs on. They are 16amps as standard, and yellow, so a bit more visible.Mechanically robust as well as intended for site use.
Mike.

I'd check the spec. 110V cable may have lower insulation resistance requirements than a 230V rated cable.

 

[BouncyBoatFolk]

I'd check the spec. 110V cable may have lower insulation resistance requirements than a 230V rated cable.

Yes, it's fine, actually thicker cores to get 16amps, and upgraded insulation properties, it's not that old festoon lighting 2 core stuff.
Mike.

^{_{Subscribers  do not see these advertisements}}

 

[slowdriver]

A further question: I have 25m orange cable that came with my previous van. It's too stiff, especially when cold to tightly coil on anything, so I have always carried it loose in large loops stashed flat in the back of the van. Always completely unwound when in use. It works but it's untidy and a bit of a pain to store. On a recent trip to Germany I bought one of these, because they are rated at 16 amps and had 2.5mm cable and rubber insulated and therefore easier to coil. I'll use it fully unwound. My assumption is that either of these 25m cables are safe in either the UK or in Europe. Our hob is gas, the heating is Truma diesel/electric (when on EHU), no electric kettle , no hairdryers. Occasionally a 230v oil-filled radiator (500 watts). I am pretty sure I am OK using either of these cables separately to run that configuration What if I connected them up to create a 50m length to reach a remote pillar? As you may detect I am gormless about electricity.

 

[cmcardle75]

A further question: I have 25m orange cable that came with my previous van. It's too stiff, especially when cold to tightly coil on anything, so I have always carried it loose in large loops stashed flat in the back of the van. Always completely unwound when in use. It works but it's untidy and a bit of a pain to store. On a recent trip to Germany I bought one of these, because they are rated at 16 amps and had 2.5mm cable and rubber insulated and therefore easier to coil. I'll use it fully unwound. My assumption is that either of these 25m cables are safe in either the UK or in Europe. Our hob is gas, the heating is Truma diesel/electric (when on EHU), no electric kettle , no hairdryers. Occasionally a 230v oil-filled radiator (500 watts). I am pretty sure I am OK using either of these cables separately to run that configuration What if I connected them up to create a 50m length to reach a remote pillar? As you may detect I am gormless about electricity.

View attachment 561447

Both cables are suitable for your needs, unwound as you state. They could also be used together in series, provided they are protected by a B16A or C16A MCB or RCBO at the campsite end. Some UK clubs prohibit the connection of cables together, but should, instead, provide a connection within 25m anyway.

 

[autorouter]

I am pretty sure I am OK using either of these cables separately to run that configuration What if I connected them up to create a 50m length to reach a remote pillar?

As I said back in post #21, it's not a safety issue, it's a voltage drop issue. The 2.5mm2 cable is perfectly capable of carrying 16A, provided it is not coiled on the drum at the time. However with twice the length, the voltage drop will be twice as much. At 16A it will be 4.8%, which is worse than the recommended 3% limit.

However if you don't take so much amps, and keep it down to 10A, the voltage drop will be 3%, which is just OK. Many hookup posts are limited to 10A anyway, and also many MHs have a 10A breaker on the mains inlet, not a 16A. 10A at 220V is 2200W, so you should stay below that limit if you use both cables.

On UK campsites someone may complain if you have a join in the cable, and someone may complain that the wire is not orange. But I think you'd be unlucky for anyone to notice.

Note that the standard blue connectors have IP44 protection against water, which means it's rain-proof but not hose-proof or proof against immersion in a puddle. So lift the connection onto a fence or hedge to keep it off the ground if possible.