Plug and fuse for transformer

[HOPS]

Hi, advice would be appreciated as I know nothing about railways or electrics. We bought a box of railway bits from a charity shop for our son(6). The contents turned out to be lima multitraffic railway set. However there was no power supply so I bought a lima transformer from ebay.

Unfortunately I failed to notice that the plug was missing.
So now I need to wire a plug to it but I know nothing about electrics. Will a 1 amp fuse be suitable? Output is 12.5V DC.

Our son will be playing with the set only with adult supervision and I won't be leaving it plugged in when not in use, but I want to make sure it is safe.

Photo attached.

Thanks in advance.

[Stese]

I'd suggest you have a look in a local facebook group for someone who have do PAT Testing... they will be able to put a suitable plug on with a suitable fuse, they'll also be able to perform other tests to ensure its safe.

[jed10]

If you are talking about the fuse in a UK 13A plug then you will be fine with a 3A fuse. Check that the power supply has a CE mark on it which should imply that it's been manufactured to european standards. Most importantly check that it is labelled suitable for 230v or 240v. Inspect it to make sure the cable outer insulation is all unbroken. Make sure there is no physical damage to the casing. If all that looks fine then plug it in and see if it works. A PAT test isn't going to help much with a double insulated item like that anyway. The visual checks I have outlined are about as good as it gets.

The secondry side of the psu will almost certainly have some sort of over current protection, probably a thermal cut out, should the system try to draw more than the rating of the psu. You aren't likely to exceed 1.5A on a small train set so that shouldn't be a problem. If it cuts out then that would imply that there's a fault in the controller. The fuse in the plug is really just a fail safe and a 3A fuse is perfect for that purpose.

[HOPS]

Thank you. No CE mark, it's possibly too old for that, but conforms to BS4435 and states it has an automatic cutout. I'll try a 3 amp fuse and see if we can test the voltage on the output to make sure it's correct.

[Nine Elms]

I think, in the first instance, ask myself "Why has the plug been cut off in the first place????"
John

[Brian]

I am a qualified PAT tester and test many items. I would advise you to fit a plug and then have the controller PAT tested. Or ask your PAT tester to fit a plug before testing the unit.
Your Lima controller is Double Insulated - noted by the square inside a square on the label and the wording Class II. This means the mains cable will be a two core - no earth wire.
The very first thing to do is carry out a visual inspection of the case, the cable entry place into the case and the whole length of the mains cable. No cracks or nicks/notches in the cable etc can be present. Anything broken or cracked or otherwise damaged means the whole unit should be deposed of and not used.
The two core cable will either be Red and Black insulation on the two wires or Brown and Blue if its new enough (doubt it) You should purchase a 13 Amp Plug fitted with a 3 Amp fuse. Ensure the cord grip holds the cables outer insulation securely and then connect Red (Brown) to the fuse side and the Black (Blue) to the neutral pin. The larger upper middle earth pin is not connected. (Bracketed colours are for newer cables) Ensure the grub screws securing the wires are tight and the insulation on the wire is up to the terminal but not inside it. There should be no bare wire showing at the connection terminal. Refit plug cover and assuming the visual was OK try it on power. It only provides a variable 12 volts DC output.

The Automatic Cut Out is for the 12 volt DC output and has nothing to do with the 240 Volt mains input. Its simply a trip that cuts the 12v power should a loco or something else cause a short circuit on the low voltage output.

[jed10]

Thank you. No CE mark, it's possibly too old for that, but conforms to BS4435 and states it has an automatic cutout. I'll try a 3 amp fuse and see if we can test the voltage on the output to make sure it's correct.

That all sounds fine. BS4435 means that it was made prior to 1990 so it's remarkable that it's still working but then it probably hasn't had a lot of use. Back when that was made there was no requirement for the manufacturer to fit a plug so it would have been a rewirable plug on it when last used anyway. It's not surprising the plug has been removed - I expect the previous owner took it off to use on something else (I often used to do that). I wouldn't worry too much about testing the output voltage. It will either work or will be dead.

Well done - what a lovely gift for your son to play with. I suspect you'll get some pleasure from it too! In due course, when you and he are ready to build a bigger model railway plesse do come back here for more advice.

[HOPS]

Thanks for all the comments and advice. The case and cable have no damage. I've fitted a plug with 3A fuse and we have tested the output with a multimeter and it looks ok. We've got the train going round on a basic track and it is running around ok.

[Brian]

Thanks for all the comments and advice. The case and cable have no damage. I've fitted a plug with 3A fuse and we have tested the output with a multimeter and it looks ok. We've got the train going round on a basic track and it is running around ok.

Well done Pleased to read all was OK