Serious soldering iron and transformer

[Wishiknewmore]

On a recent outing to a French car boot I acquired a heavyweight soldering iron and its transformer, for very few euros!

The soldering iron is marked 125v hence it came with its very own transformer

Firstly it does ‘warm up’ with the transformer – didn’t try it for too long’ but this leads me to more questions:

The soldering iron, although marked 125v, looks as if there may have been a able stuck over where it says 125v – so how would I determine if it actually is 125v or 220/230v?

Secondly the transformer, I believe it is an isolating transformer as using the DMM I don’t get any ‘connection’ between the input and output side, and the terminal plates are marked ‘PRIMAIRE AND SECONDAIRE’ – how can I confirm this?

I suspect the answers will be above my paygrade but I still have to ask!

Philip

PS: at present the soldering iron/transformer and I are currently 500 miles apart

[Dave Moll]

To check for isolation between primaire et secondaire, the best tool for the job would be a megger.

The simplest check regarding required voltage would be to power it up via the transformer and see whether it gets hot enough to melt solder. Otherwise, if it has a wattage rating marked on it, see what current it draws at 125V (assuming that's the voltage delivered by the transformer) and see how current x 125 compares with the rating. If they're in the same ballpark, then it's rated at 125V. If it's about a quarter, then it's rated at the higher voltage.

I do love the traditional French approach to electrical safety!

[hannahs radios]

An even easier way to tell if its an isolation TX is put one lead of your DVM on to earth and the other on the primary terminal and you'll get 220 volts (ish) now move it to the secondary if it reads 125 volts(ish) then its NOT an isolation TX if you get a silly reading no reading etc then it IS an isolation tranny. OR put a neon screwdriver on the primary it will light and go brighter when you touch earth on the secondary if it does the same then it ISN'T an isolation TX you get the idea

[Oldcodger]

Alternatively as in #3-but with voltage disconnected from primary whilst making test connections (for safety)
check current when iron is connected to 125v. Then check voltage on both sides of secondary WRT earth. Both voltages minimal or silly values, it's pretty certain that it's an isolating transformer. BUT-
Connect iron to terminal showing higher voltage ( IF BOTH THE SAME VOLTAGE- DO A TEST ON BOTH SIDES TO EARTH)and other side of iron to earth. Measure current. Minimal = isolation tx. Anything more than a few milliamps, then TX is not an isolation TX, or is leaky. For safety of operator, I'd suggest a voltage check/megger test of iron body/tip to earth, as fingers will be in contact with solder and tip when using iron. Any voltage on tip, WRT earth will give operator a belt when solder is being melted.

[David Simpson]

Philip, from what I can see from the pictures, the whole caboodle looks pretty knackered. I wouldn't recommend powering it up as the cabling looks rather perished.
As Dave says, you need to use a Megger to test the insulation of the T/F, ie. between the Pri & Sec, and between either winding & the metalwork earth. If its a 1: 1 isolation T/F, a DMM on the resistance range will reveal the same resistance for pri & sec. Or use an LCR meter & also check the Inductance - might be a Henry or so for the windings.
Going by a recent thread on soldering iron temperatures, that big heavy bit wont be much use for vintage radio soldering. Does it have a temp or wattage stamped on a label somewhere ?

Regards, David

[Peter.N.]

I like the 'health and safety' aspect, reminds me of my youth.

Peter

[Wishiknewmore]

Thank you all for your comments.
There aren’t any markings that I can see as to temperature or wattage, I note the comments about wiring (and plugs), fear not, it would be my intention to replace all; initial power up was only to see if there was any signs of life.
I will check voltages and currents draw, perhaps using the neon screwdriver method first, I don’t have any access to a Megger but I will investigate.
The probable designed function of the soldering iron was for soldering zinc guttering and waterproofing which is very popular in that part of France, but more commonly propane powered devices would be used.
The responses have given me a direction to proceed when I get back
Many thanks
Philip

[Radio1950]

Hi there,
If you have to ask these questions, I assume that you cannot assess and test appropriately.
The whole thing looks decidedly "dodgy".
I suggest you tread carefully and get a qualified person to assist you in your decision to either restore or dump the lot.
Stay safe, and best of luck.

[mole42uk]

I do love the carrying handle.

[Dave Moll]

Assuming it can be made safe, it's the sort of thing that's useful for soldering to (or desoldering from for that matter) chassis directly - but don't dump it.

[HamishBoxer]

One not for the faint hearted!

[Refugee]

It looks like it would clean up nicely and a 500V test voltage would be pretty easy to create from a battery oscillator and CRT line output transformer for testing.

[Radio Wrangler]

It looks more like its past lies in stained glass than in electronics...

David

[philthespark]

I used to have one of those, or at least one very similar, it was a "solon" by Henley, I seem to remember it being around 100-150 watts, and they were used for soldering lugs on very large cables, no doubt they were used for other things too, but that was what the firm I "borrowed" mine from used them for.
Quite often there was a 110v supply in the area's where they were used, however they did have a small transformer for use where there was no 110v. BT used a similar thing with 25V irons in their exchanges, they had a 6.3 mono jack plug on them and plugged into a socket on the frames in the exchange, however they too had a small transformer to enable them to be used elsewhere.

https://www.ebay.co.uk/sch/i.html?_n...soldering+iron