Current draw via the caravan power supply cord

patrol03 · Senior Member

RE: Current draw via the caravan power supply cord

oldtrack123 · Guru

Hi Tom
Yes I missed those two ,but seeing as the extension lead socket also has a problem, the Inlet on the van WILL be damaged &
need replacing by that electrician, And I mean ASAP before you have a more serious situation!!

When THAT is done then I suggest you immediately use a NEW approved extension lead!!
Do not use one that has previously been used in THAT inlet socket, or your troubles could start all over AGAIN.

oldtrack123 · Guru

patrol03 wrote:
I would think that most leads used by caravanners, while branded 15amp and having 15 amp fittings,are really 1.5mm wire with thicker than standard outer insulation.They feel heavier and actually are, but due only to the extra insulation. It took me a while to find 2.5 mm sq but now no more problems with discoloured wire ends at the plug due to overheating.It also never ceases to amaze me how many campers roll up their excess lengths of lead between the van and the power pole into a neat coil configuration.This coiling up of leads will also produce heat as a mini radiator has been created.

Hi

Yes , quite possible, as that is the normal "APPROVED" Extension lead & the 15A rating is the genuine rating for 1.5mmSq

2.5mmSq cable has a 20A rating.

The cable size is very very unlikely to be the problem in this case

There must be other factors one of which could be a faulty overload breaker, BUT they rarely fail to trip at their rated current.

Most failures are premature tripping, with currents under rated currents.

However as the op has decided to have it replaced with a RVD/ MBO, RATED 16A, as he intends to use a generator [a very wise move smile ], that will remove the possibility of the breaker failing to trip.

But he needs to get the inlet socket & the wiring from it in the van checked WITHOUT DELAY.!

Your point about coiling is very valid,

The current rating is based on the cable being in free air for its full length, not enclosed /rolled up/covered.

-- Edited by oldtrack123 on Sunday 15th of November 2015 05:44:49 PM

ShortNorth · Senior Member

While we are talking about power connections, I had an amusing situation a few days ago. I was walking down to the end of the park to dump some rubbish in the skip bin. On the way back I passed a brand new 'full size' Avida motorhome that had just arrived, and the bloke was trying to plug in his power cord - as I walked by, he asked me 'excuse me mate, I'm new to this, how does this plug in' - he was trying to plug his 15A motorhome cable into a 10A Amphibian into the park 15A socket. As a retired electrical engineer, I quickly explained the purpose of the Amphibian - the motorhome dealer convinced him he need to buy one, but FAILED to advise him he only needed to connect it at home. At least, now he knows how to use it properly.

Baz421 · Guru

Delta18 wrote:
I would seriously doubt your fridge is 1500w.
More likely 2 - 300w I would say.
Probably advisable not to run Microwave, electric jug & toaster at the same time.
I have unthinkingly done this in a park and the rcd on the power stand has tripped out.
Cheers Neil

Oldtrack you there??? Stop the bus,,,, Does the RCD trip for overload?????? or does it trip for current to earth.

KFT · Guru

G'day Baz

Usually the RCD and Overload functions are built in to a single device. If a current to earth fault occurs the RCD will trip the breaker

If a current overload occurs the breaker will trip

Either way the same switch lever trips downwards(normally)

Frank

Baz421 · Guru

KFT wrote:
G'day Baz

Usually the RCD and Overload functions are built in to a single device. If a current to earth fault occurs the RCD will trip the breaker

If a current overload occurs the breaker will trip

Either way the same switch lever trips downwards(normally)

Frank

OK thanks Frank. Just looked at the house (they are separate) and van single device.

oldtrack123 · Guru

Baz421 wrote:
KFT wrote:
G'day Baz

Usually the RCD and Overload functions are built in to a single device. If a current to earth fault occurs the RCD will trip the breaker

If a current overload occurs the breaker will trip

Either way the same switch lever trips downwards(normally)

Frank
OK thanks Frank. Just looked at the house (they are separate) and van single device.

Hi ,
And that is the problem with a single unit
What caused it to trip":
[a]an earth fault[ fast trip , almost instantly on resetting]
a short circuit [perhaps slightly longer ,but still fast]
[c] or an overload , the level of overload will determine how long it takes to trip
That could range from seconds to hours.

Unless the reason can be clearly determined as an overload, the reasons should be investigate urgently to avoid bigger problems!!

-- Edited by oldtrack123 on Monday 16th of November 2015 12:43:19 AM

greyhoundtom · Senior Member

Sorry guys but it seems I still have a question to find an answer to in regard to having an RVD fitted to the van's 240 volt supply circuit.

And that is, will the RVD function as it should when the van is plugged into a caravan park electrical supply as at that point in time it is most likely plugged into a MEN system circuit, or do I have to have both the RVD and a RCD fitted to cover all eventualities?

{Or I could just have an RVD fitted and disconnect the earth wire at the van's power entry point.} I'm joking...I'm joking....I'm joking............

electrician coming on Wednesday morning.

-- Edited by greyhoundtom on Monday 16th of November 2015 11:08:54 AM

KFT · Guru

G'day Tom

The RVD will cover all situations including generator or inverter supply as well as mains from a site supply or a home outlet.

The device will detect a fault and force the RCD to trip.

hope that helps

Frank

erad · Guru

Cord connections can vary and you get good ones and bad ones.One factor not mentioned here is coiling up excess cable. If the cable is left coiled up - either round a drum or whatever, or simply coiled up on the ground, it will get quite warm without heavy power draw. A coil can generate inductive loading, so unfurl it and lay it out on the ground. Thay way, more air can get to it to cool it as well. This doesn't help with the pin connections in the plugs, but it helps to keep the cable cooler.

I am always at my wife about loading up our van's power. She has the A/C running as a heater, the microwave going and then she turns the electric jug on. Surprisingly, the breaker doesn't trip, but you can tell the voltage has dropped dramatically because the fans on the microwave and the heater both slow a lot. She would turn the toaster on as well, except that we don't have enough power outlets in that area. I have only had the breaker on the van trip once. This was when I plugged a frypan in and turned it on. It hadn't been used for a long time. I tried a few times and it still tripped, so eventually I took it outside and plugged it in to another power pole (presumably no RCC Breaker). It worked OK there and afterwards, it worked fine in our van. I guess that there was some residual moisture in the control unit which dried out. A RCC or Earth Leakage breraker will trip at 30 mAmps. How that 30 mA comes doesn't matter. All appliances have some earth leakage, and if you plug enough in and the total leakage exceeds 30 mA, then the breaker goes. Remove one item and it may all be OK

oldtrack123 · Guru

Hi Erad

Sorry but saying that" A coil can generate inductive loading, " is not quite correct.

That does not occur with extension leads or where both active & neutral are in very close proximity to each other
It does occur when one or the other is coiled

The real problem with rolled up /coiled extensions is the lack of air for cooling to the full surface & length
The rating is based on the full length being exposed to air ,. not coiled, not covered , not enclosed in a box etc

-- Edited by oldtrack123 on Monday 16th of November 2015 02:46:25 PM

oldtrack123 · Guru

greyhoundtom wrote:
Sorry guys but it seems I still have a question to find an answer to in regard to having an RVD fitted to the van's 240 volt supply circuit.

And that is, will the RVD function as it should when the van is plugged into a caravan park electrical supply as at that point in time it is most likely plugged into a MEN system circuit, or do I have to have both the RVD and a RCD fitted to cover all eventualities?

{Or I could just have an RVD fitted and disconnect the earth wire at the van's power entry point.} I'm joking...I'm joking....I'm joking............
electrician coming on Wednesday morning.

-- Edited by greyhoundtom on Monday 16th of November 2015 11:08:54 AM

Hi

The quick simple answer is IF you purchased the RIGHT RVD it will function with ,all provided the MEN supply has the correct polarity as defined in the Standards.

Did you seek advice from Safelec or RVPowerstream regarding type??

Which model do you have??

-- Edited by oldtrack123 on Monday 16th of November 2015 02:52:19 PM

greyhoundtom · Senior Member

Hi Oldtrack123,

At this point in time I have made no enquiries about the type of device best suited to the van, as I assumed the electrician would be knowledgeable enough to select the right one for the job.

I have simply made him aware of the problems encountered in regard to the overheating of the active plug contact of the power supply cable damaging the plugs, the fact that the overload system was not tripping at a load level high enough to damage the plugs, and that I needed an appropriate RVD fitted so as to provide increased safety protection while the van was plugged into a generator.

oldtrack123 · Guru

greyhoundtom wrote:
Hi Oldtrack123,

At this point in time I have made no enquiries about the type of device best suited to the van, as I assumed the electrician would be knowledgeable enough to select the right one for the job.

I have simply made him aware of the problems encountered in regard to the overheating of the active plug contact of the power supply cable damaging the plugs, the fact that the overload system was not tripping at a load level high enough to damage the plugs, and that I needed an appropriate RVD fitted so as to provide increased safety protection while the van was plugged into a generator.

Hi Tom

Do not be surprised If he looks at you with a blank look & then says you mean a RCD

Just make certain it is A RVD, not an RCD!! ,which will not give any protection against shocks to earth with a generator plugged into the inlet socket.

Most Domestic style electricians have not heard about RVDS & certainly will not be carrying one in their van.

greyhoundtom · Senior Member

Oldtrack123

Thank you for all your excellent advice it is certainly appreciated, and this electrician was recommended by the van park I'm currently staying in, and should therefore have some additional experience with RV's. At least now I am clued up a little better about what is needed to best solve the problems with the vans electrical system.

I have also had an opportunity to learn a bit more about the functions and limitations of RVD's and hope to discuss this with the licensed electrician.

including this statement by associate professor Blackburn:

--------------------------------------------------------------------------------------------------------------------

4 Practical applications of the RVD device

The RVD device is not able to be used in all situations. It cannot, for example, be used in lieu of the MEN system used in utility-supplied distribution systems in Australia. The RVD method has to be used with an earth-free local system and thus the overall MEN earthing system of the extended public distribution supply system would have to be compromised to use RVD.

However the RVD system can be applied in local networks if those networks are isolated from the utility supply system by an earth free isolation transformer or if the local system is supplied from its own dedicated generator system. In such cases the local system is able to be operated earth-free and the safety advantages of the RVD system can be realised.

-----------------------------------------------------------------------------------------------------------------------

This statement still has me a little unsure in regard to the functionality of an RVD when used in a situation where the circuit is connected to a MEN system such as when the van is plugged into the caravan park power supply..... Hence my stupid quip about disconnecting the earth wire of the power supply from the caravan park.

[Doule Edit] Hi oldtrack123'

Just found one of your old posts that clearly stated that an RVD is not an replacement for an RCD and it functions in conjunction with an RCD, so at least now my mind is clear on all that and i will get the current RCD replaced plus a new RVD fitted.

Thanks again,

-- Edited by greyhoundtom on Tuesday 17th of November 2015 06:15:18 AM

-- Edited by greyhoundtom on Tuesday 17th of November 2015 09:04:22 AM

-- Edited by greyhoundtom on Tuesday 17th of November 2015 09:05:30 AM

oldtrack123 · Guru

Hi Tom
Yes , That is the way to go ,but you can get the combined unit, RCD/RVD direct from Safelec or RVPowerstream.

greyhoundtom · Senior Member

oldtrack123 wrote:
Hi Tom
Yes , That is the way to go ,but you can get the combined unit, RCD/RVD direct from Safelec or RVPowerstream.

Thank you I wasn't aware of that and will see if I can organise something in that regard ASAP.

mjt57 · Senior Member

Baz421 wrote:

I don't trust ANY overload protection in CP's. Have you seen the condition of some, barely able to move the switch.

Discussing this with the sparkies at work tonight. They were saying that some of the older parks have questionable electrical systems, often with no RCB/Earth leakage protection, and having a dozen or so outlets looped back to 40a fuses or similar.

The regs changed recently where new installations have to have proper protection systems in place, they were saying. But the regs aren't retrospective.

How common is it to find caravan parks with substandard electrical supplies for powered sites?

PeterD · Guru

erad wrote:
Cord connections can vary and you get good ones and bad ones.One factor not mentioned here is coiling up excess cable. If the cable is left coiled up - either round a drum or whatever, or simply coiled up on the ground, it will get quite warm without heavy power draw. A coil can generate inductive loading, so unfurl it and lay it out on the ground.

Yes, a coil can generate inductive loading, but only if the current flows one way in all the wires. However with a coiled power lead you have equal currents flowing in opposite directions. One current cancels out the other. That's how we constructed non-inductive wire wound resistors ig the steam driven radio days. The heat build up is totally from the resistance in the power lead.

Aus-Kiwi · Guru

If t don't uncoil my lead useing plasma cutter the lead gets warm .. Doesn't do the same uncoiled .. High loads though..
As said coiled covered wire de rates it..

Aus-Kiwi · Guru

We are confusing things here . Gone off subject .. The OP was asking about current draw of the supply cord..
There are devices which can be fitted to the house outlet to cord which protects the lead..
Oxidation on plug doesn't help make good contact . Salt air at the beach causes all sorts of corrosion issues ..
If anything check house breaker the Lead is plugged into is low enough for cable, plug protection..

An RVD protects from electric shock .. Fit proper circuit breaker you'll be fine ..
Your confusing the electrician with inside protection.. Nothing to with generaters etc

oldtrack123 · Guru

Aus-Kiwi wrote:
Yea seems he has each circuit in van protected only . I hope .. Nothing on sub wires ? Sheesh ..

HE WILL HAVE, SHALL HAVE, a 16 A OLCB in the van supply from the supply socket on the VAN!

Any Sub circuits in the van SHALL have at least 15A rated cable!

They cannot be overloaded as the RCD ? is no doubt A RCD/16A OLCB combo, acting as a mains switch/ RCD/ OLCB

ALL quite OK & normal practise!

oldtrack123 · Guru

Aus-Kiwi wrote:
We are confusing things here . Gone off subject .. The OP was asking about current draw of the supply cord..
There are devices which can be fitted to the house outlet to cord which protects the lead..
Oxidation on plug doesn't help make good contact . Salt air at the beach causes all sorts of corrosion issues ..
If anything check house breaker the Lead is plugged into is low enough for cable, plug protection..

An RVD protects from electric shock .. Fit proper circuit breaker you'll be fine ..
Your confusing the electrician with inside protection.. Nothing to with generaters etc

He was asking about overheating of the cord.

IF it is an approved 15A extension cable, it must be able to carry 15A without overheating

Both the van's RCD/OLCB & the park's RCD/OLCB SHALL be rated @16A

What size Additional in line OLCB would you suggest & just what would it gain ?

Or are you the confused or confusing one??

-- Edited by oldtrack123 on Friday 20th of November 2015 12:58:45 AM

Aus-Kiwi · Guru

He's talking about RVD safety switches to electrician which have bugger all to with cord .. As said proper breakers .. Done ..
As said any other issues is bad contacts ..

greyhoundtom · Senior Member

Found this article a great read in understanding RCD and RVD uses and limitations.

http://safe-electricaltechnologies.com.au/assets/Uploads/White-Paper-1-Associate-Professor-Trevor-Blackburn.pdf

oldtrack123 · Guru

greyhoundtom wrote:
Found this article a great read in understanding RCD and RVD uses and limitations.
http://safe-electricaltechnologies.com.au/assets/Uploads/White-Paper-1-Associate-Professor-Trevor-Blackburn.pdf

Hi Tom

Yes it is a good article & explains the differences nicely BUT, IT IS OUT OF DATE

The range of Protex , Safelec units has increased. smile

Different units NOW available cover:

[a]Small generators [fully isolated] which simply shut down the generator output

[ b]all "fully isolated" isolated generator or inverters & turn off supply

[,c]Non isolated" RCD protected "generators & inverters where they give that better line of protection as described in the article

[d]Polarised units that can be used with any M.E.N supply, again giving that additional level of protection

That is why ,at this time , it is best to contact the makers/suppliers direct to ensure of obtaining one suited for actual situation /type of supply .

You may find that many/ most electricians areas yet not familiar with the product

Around 4years ago just one type came onto the market/ was available, but there have ben great leaps since then. biggrin

PeterQ

-- Edited by oldtrack123 on Friday 20th of November 2015 03:39:01 PM

greyhoundtom · Senior Member

You are right as usual....... eventhough the electrician seemed to know what I was talking about when I explained the problem over the phone, and my wish that a RVD be installed as well as replacing the existing RCD so that this would provide an additional level of safety when my van was plugged into a generator or a non MEN power circuit, and said yes I do carry those in my truck.

When it came down to the crunch he replaced the RCD, said there is nothing wrong with the van wiring, all your problems with burned plugs were caused by loose connections, you don't need a RVD even when you are plugged into a generator as your RCD will function as normal.

I paid his bill and he went off again.

Bugger

KFT · Guru

G'day Tom

He does not appear to understand the principle of isolated supplies or the theory of operation of an RCD.

I can assure you the RCD component of your combined unit will not operate as normal when connected to a generator UNLESS the generator also has a correctly wired and permanently fitted RCD.

I am also sure PeterQ will agree with me.

Frank

oldtrack123 · Guru

KFT wrote:
G'day Tom

He does not appear to understand the principle of isolated supplies or the theory of operation of an RCD.

I can assure you the RCD component of your combined unit will not operate as normal when connected to a generator UNLESS the generator also has a correctly wired and permanently fitted RCD.

I am also sure PeterQ will agree with me.

Frank

Hi Frank

Sadly,

Totally agree

It still seems many electricians have some lack of knowledge, even as far as generators & RCDs operation is concerned

But again sadly NOT unexpected, but not good when THEY do not understand ,yet are giving people "advice"???

From my earlier post "You may find that many/ most electricians are as yet not familiar with the product" smile

TOM

if you contact Ian at Powerstream Rv , he may be able to help you with an electrician in the Melbourne area who knows, has installed the product

http://powerstream.com.au/contact_us.php?osCsid=c7ca694468b5c15369d01964d8509145

PeterQ

-- Edited by oldtrack123 on Sunday 22nd of November 2015 02:19:40 PM