Jump to content

cheekychops

Recommend a robust plug..

Recommended Posts

Just use a cheap robust connector designed to do the job:-

  • Speakon - a modern connector with screw terminals good for at least 40A which will take suitable 4-way cable.
  • XLR - good for typical layout requirements (more pins means less current, but the 4-way should be OK for 10A, and the 3-way for 15A). Available in good quality from reputable manufacturers, and cheap and shoddy from others! Different numbers of pins as well as male and female allows the use of multiple connectors for a single baseboard join. Needs to be soldered.
  • 'D' connector - lots of pins and should be good for 5A, but can only fit 16/02 wire or smaller so will usually need parallel wires for power and track bus circuits. Again can be variable in quality so go with a known good manufacturer.

There is really no need to go: giant (trailer plug), inadequate (SCART), short operational life (Molex), Dangerous (any mains connector of any type at all), unreliable (jack plug), loose (banana plug), ancient and falling apart (GPO or similar connectors from ye olden days).

 

More expensive options like the Anderson Powerpole and military round connectors can be useful - but can be hard to justify the cost over the three main options listed above that are both good and cheap.

  • Agree 6
  • Informative/Useful 1

Share this post


Link to post
Share on other sites
16 hours ago, DavidCBroad said:

 On a caravan the Earth Pin could take 115 watts

If an earth pin is taking 115 watts with 10A current I'd get it replaced. It must have a resistance of  around 1 ohm and isn't a very good earth pin!

 

  • Like 1

Share this post


Link to post
Share on other sites
1 hour ago, Suzie said:

 

 

More expensive options like the Anderson Powerpole and military round connectors can be useful - but can be hard to justify the cost over the three main options listed above that are both good and cheap.

Unless of course you need to operate your model railway whilst invading a small South American country at the same time :lol:

  • Funny 3

Share this post


Link to post
Share on other sites
1 hour ago, Suzie said:

Just use a cheap robust connector designed to do the job:-

  • 'D' connector - lots of pins and should be good for 5A, but can only fit 16/02 wire or smaller so will usually need parallel wires for power and track bus circuits. Again can be variable in quality so go with a known good manufacturer.

 

I'd take the D connector off that list.

Many aren't made well enough to withstand regular plugging/unplugging.

If you buy quality ones from a well known name you should be OK but cheap ones a definite no.

  • Agree 2

Share this post


Link to post
Share on other sites
35 minutes ago, melmerby said:

I'd take the D connector off that list.

Many aren't made well enough to withstand regular plugging/unplugging.

If you buy quality ones from a well known name you should be OK but cheap ones a definite no.

I'd go for turned pin versions over stamped pin ones for better reliability.

  • Agree 4

Share this post


Link to post
Share on other sites
3 hours ago, sharris said:

If an earth pin is taking 115 watts with 10A current I'd get it replaced. It must have a resistance of  around 1 ohm and isn't a very good earth pin!

 

I do wonder why you posted this comment and mis quoted me.  I just quoted the real world load, on a 7 pin plug,   The seven pin has two indicator connections two side lamp connections, a  stop light connection and a rear fog connection and one earth pin.  21 watts X 2 for brake lights  21 watts X 2 for  two rear fogs,  5 watts X 2 for the tail lights, and 21 watts for the indicator.  115 watts all returning though the single earth pin which therefore has to take the whole load. 115 watts at 12 volts is almost 10 amps. And the plugs are used by literally tens of thousands motorists who haul trailers or caravans.  

Share this post


Link to post
Share on other sites
10 minutes ago, DavidCBroad said:

I do wonder why you posted this comment and mis quoted me.  I just quoted the real world load, on a 7 pin plug,   The seven pin has two indicator connections two side lamp connections, a  stop light connection and a rear fog connection and one earth pin.  21 watts X 2 for brake lights  21 watts X 2 for  two rear fogs,  5 watts X 2 for the tail lights, and 21 watts for the indicator.  115 watts all returning though the single earth pin which therefore has to take the whole load. 115 watts at 12 volts is almost 10 amps. And the plugs are used by literally tens of thousands motorists who haul trailers or caravans.  

How did I misquote you? I used the 'quote' button on the site (unless you edited your post after). 

You said 'the earth pin could take 115 watts' - your exact words.

 

What flows through the earth pin is amps, not watts. All your lights may, combined, have a total of 115 watts, but those watts are not flowing through the earth pin - 10A or so of current is flowing through that earth pin. Ideally, that earth pin should be contributing no watts to the scenario. If your battery was somehow to be 24V, and the caravan lights took 230W, there would still be exactly the same current going through your earth pin - the same strain on it, or your battery was 6V, and the lights took 57.5W, the same current again - it just doesn't make sense to say how many watts are passing through the connector, it's the current it's rated for.  In your post you appear to be liberally exchanging watts and amps. Particularly when the currents involved are sufficient to do some damage, some rigour should be applied to the correct use of units.

 

 

Share this post


Link to post
Share on other sites

The pins on a trailer plug should be good for twenty amps, in the olden days you would often have had a 10A fridge running as well as the lighting (using what is now the reversing light pin). It is still far too big to be practical for layout use. The new 13-pin versions are a similar size so too big, but a much better connector than the two varieties of 7-pin.

  • Agree 1

Share this post


Link to post
Share on other sites
9 hours ago, DavidCBroad said:

I do wonder why you posted this comment and mis quoted me.  I just quoted the real world load, on a 7 pin plug,   The seven pin has two indicator connections two side lamp connections, a  stop light connection and a rear fog connection and one earth pin.  21 watts X 2 for brake lights  21 watts X 2 for  two rear fogs,  5 watts X 2 for the tail lights, and 21 watts for the indicator.  115 watts all returning though the single earth pin which therefore has to take the whole load. 115 watts at 12 volts is almost 10 amps. And the plugs are used by literally tens of thousands motorists who haul trailers or caravans.  

 

In your scenario there is heat - lots of it in the bulbs and this is where the work is being done converting the electrical energy into a little bit of light and a large amount of heat - put you hand on the bulb if you don't believe me :)

 

Now put your hand on the connector, it should be cold - if it isn't then there is a resistance in the connector and some work is being done as the energy is converted to heat.

 

the formula is simple;

 

I*I*R=W or current * current * resistance = watts

 

which shows that the current passing through anything doesn't matter if there is no resistance, watts will always equal zero because anything multiplied by zero is zero. It is ONLY when there is a resistance that watts can exist and these watts will generally appear as heat (light is a visible form of heat).

 

  • Agree 2

Share this post


Link to post
Share on other sites

Most connectors that are used by railway modellers are not really suitable for purpose.

 

Anderson Powerpoles are, they are designed to be made and broken under power and are generally rated for 10,000 mating cycles.

The same housing is used for 1.5mm2, 3.0mm2  and 6.0mm2 conductors. The PP30 is used by NTRAK as a standard connector.

 

The PP30 can carry 30 Amps. They are available in lots of different coloured housings which can be slid onto each other to form multi-pole, polarized connectors (polarizing is the ability to stop the wrong plugs/sockets being connected by turning one or more connector so that the blade is at right angles).

 

I got mine from: http://www.torberry.co.uk

 

They are also available from RS , Farnell and https://www.12voltplanet.co.uk/anderson-pp15-30-45-powerpole-connector-housings.html

 

If you want wiring standards for, board to board or module, DCC you can't do much better than the following:

http://www.ntrak.org/documents/NTRAK Manual.pdf

 

Cheers Godders

  • Agree 2

Share this post


Link to post
Share on other sites

I use Anderson powerpoles between boards and most everything else.   I find that ganging more than 8 of them together makes them difficult to connect and disconnect. 

 

Brendan

Share this post


Link to post
Share on other sites

teh trouble with Powerpole is its gets quite expensive to arrange panel mounting etc especially for a couple of pins 

Share this post


Link to post
Share on other sites
On 16/01/2020 at 13:11, Godders said:

 

If you want wiring standards for, board to board or module, DCC you can't do much better than the following:

http://www.ntrak.org/documents/NTRAK Manual.pdf

 

Cheers Godders


Which, surprise surprise, advocates Anderson power poles.

 

On 15/01/2020 at 18:42, Suzie said:

More expensive options like the Anderson Powerpole and military round connectors can be useful - but can be hard to justify the cost over the three main options listed above that are both good and cheap.


Solid advice as usual from Suzie. Agree about Speakon and XLR, less so , like Melmerby, about D connectors.

 

I have many powerpole connectors, so was able to spread the cost of the bespoke crimping tool (that makes forming the fittings quick, simple and reliable).

 

If the OP needs to only make a small number, Speakon or XLR get my vote. If the number increases, powerpole becomes my preferred choice. 

 

 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.