42Vac control

silva.foxx · Oct 17, 2011

Anyone any history or stories on 42Vac control voltage? :thinking:

Seen parts in our stores but never seen it anywhere I've worked.

Where is/was it used?

Was it once as common as 24Vac?

TIA// s.f

netblindpaul · Oct 17, 2011

Welding sets is my first thought, don't know why it would be 42V a.c. though!

silva.foxx · Oct 17, 2011

I've seen relays and contactors aswel as lamps. All the older (but very much wiser) guys have gone who may have known. I've asked here cos I know there are a few wise guys. :detective:

Knobhead · Oct 18, 2011

You’ve got me on that one!

View attachment 8326

malcoa · Oct 18, 2011

i've come accross control voltages of 42Vac also 36VDC, it tends to be specific to certain machine manufacturers, i think the idea is to possibly limit the availability of spares and force people to purchase parts only from the machine manufacturers

Knobhead · Oct 18, 2011

Silva, do you have any Demag cranes or winches? It’s the sort of crazy thing they’d do. As malcoa said anything to stop you buying off the shelf spares.

silva.foxx · Oct 18, 2011

I'll have a deeper delve tomorrow when I'm back in. I'll look through some old dwgs and see if I can answer my own Q.

netblindpaul · Oct 18, 2011

s.f,
Please let us know!

netblindpaul · Oct 18, 2011

Tony said:
Silva, do you have any Demag cranes or winches? It’s the sort of crazy thing they’d do. As malcoa said anything to stop you buying off the shelf spares.

Tony,
Do you mind please I worked for Mannesman at one time!

Knobhead · Oct 18, 2011

netblindpaul said:
Tony,
Do you mind please I worked for Mannesman at one time!

You’re to blame then :wink_smile:

silva.foxx · Oct 19, 2011

Found some 42Vac control today... a conveyor control panel to transfer beer bottle crowns from the hopper to the machine. I also found it on a Filler, previous as lighting supply.

But why 42V? Suppose I could ask why we use 24V, or any other voltage for that matter!<br><br>Long shot: 24 is 1/10th of 240v... 42 is roughly 1/10th of 415v... easy ratio for step-down transformers?

pmac10 · Oct 19, 2011

could be to make the supply compatible with the requirements for associated electronics, (guessing here), had one machine with a transformer, 400vac primary and a secondary tapped for 9,12,15,19,24Vac, all to keep one (complex) circuit board and control circuit happy.

vaughant · Oct 22, 2011

With our place we use a lot of 48v control stuff,which I'd never seen before.
When I asked the question I was told that it was due to some guideline that any voltage below 50v is "safe",I think it's titled SELV from my reg days.
I did mention why they didn't just use 24v dc as that falls into all categories and I was told that "probably cos the mills ten years behind everyone else!!!".
Which I can believe,we've got something called CT or control techniques drives in our place,the guy was so impressed to show us that all the parameters are saved on a "card",you don't need to download it all to disc anymore,you just keep the "card" in the machine.
What like a memory stick siemens had back at the turn of the millennium?
We were told that was "too complicated".
Ok.

netblindpaul · Oct 22, 2011

vaughant,

I know CT stuff, we used it on some of our machines there was some on Fabian Way on the Transit rear axle half shaft oil seal grinder, I know, as you are aware as I installed, commissioned & did the training on that machine!

CT is not too bad it has its quirks like all do.

They actually still do true old fashioned dc variable speed drives!

vaughant · Oct 23, 2011

Hi Paul,good to hear from you again!!!
I never knew that about the 1/2 shaft,I only really went there on o/t but I suppose I should have paid more attention.
I've not done too much with this CT caper,their all over the mill though so I suppose I should learn a bit more.
Their main man seems to be a chap called frank Pitt,very knowledgeable chap although perhaps on too high a level for someone like myself,I reckon you and him would enjoy yourselves talking about harmonic fluctuations etc!!

How's business going fella?

Last time we spoke it sounded as though things were picking up just fine?

I'm sure your aware but most of the old ford engineers/foremen etc ended up in bridgend engine plant,I bet they'd be glad to hear from someone like yourself,they always seem to struggle with good hands on engineers.