240v 90w tube, on a std 13a plug?

[Toby Hope]

Hi, i’m sure this has been answered but can’t find it.

my laser machine is on a 13a plug i’m on 240v single phase , this is how the machine originally came .

i’m wondering what the maximum current drawn would be, it’s been working fine for years on the plug but that’s not to say it should be ...

i have installed a 16a circuit in the workshop just in case , but wondering if i need to change it over to 16a plug or not.

anybody know what it should be on based on the tube

thanks
Toby

[sebastien laforet]

not sure about what "gauge" you are talking. in my part of the world we use the standard units (the ones based on 10! not 2.54, or 12, or 5681 (yard to mile, what the fuck!))

referring to https://fr.wikipedia.org/wiki/Standard_Wire_Gauge your "13a" wire should be 2,337mm large.

here in france, we use the section of the wire in mm2, so your 13a would be pi*(2.337/2)^2 = 4.28mm2.

we usually use 1.5mm2 for 16amp, and 2.5mm2 for 32amp, so you should be totally fine with your wiring.


but!!!

i you use AWG and not SWG... (http://www.latelierducable.com/cable/ca ... dire-quoi/) you have different values.. and your 13 gauge is down to 2.62mm2 of section... still close to our 2.5mm2 standard that allows 32 amps. ok, that's still enough, no risk of fusing your wires.


the last word : stop fucking with "units" that no one uses besides you in all the world!

[Jeffrey Aley]

Hmm. Sebastien seems to be having a bad day.

I think the only "crime" here is that the Original Poster used a lower-case "a" for "Amperes" instead of an upper-case one. I don't see anything related to wire gauge / gage.

Anyways, to answer the question, the 90 Watt tube is not being operated at 240 Volts. That's why you're confused. The tube is 90W at several thousand volts. So the current as 240V is relatively small. Of course there are inefficiencies in the power supplies, etc., but I would think that a circuit that can supply 13 Amps at 240 Volts should be sufficient. I run my (50W) laser on 120V at 15A.

I hope this helps.

[Pete Cyr]

Wow Sebastian.....I think you are a bit confused...”a” = amp. Not gauge.
A bit over the top with your remarks.

[sebastien laforet]

sorry for the post. i'm pretty sure i saw somewhere this "gauge" think with "a" as unit (like AWG?)... also, 13A seemed like an odd value for amperes and made some sense if expressed in "gauge".

my mistake.

[Frank Small]

Toby, let me address your question first. The short answer is you should be OK as is.

In the USA we typically use 120VAC to power these machines, my machine is no exception. I have a volt/current meter attached to the mains and with the water pump, air pump, fume extractor fan and a laser running it draws less than 5 amps. If this same setup was in the UK at 240VAC it would draw half of that. Higher voltage less current, smaller wire, ohms law stuff.

For users here that might not understand where Toby got the 13a from I have included a picture of a typical British plug with a 13A fuse. In the UK most everything that plugs into standard receptacles has a fuse in the plug thereby protecting the cord and the appliance, lamp, etc as well. This adds an extra layer of safety.

In the USA we use all the things Sebastien hates. I agree being a user of the imperial measurement system is a pain in the butt however we are stuck with it.

I remember back in the third grade (early sixties) there was a movement to go metric in the United States and our teacher said this was going to happen within a few years. Well that didn’t, now I have two sets of tools SAE and metric to work on stuff, c,est la vie.

I can achieve more accurate measurements using the metric system and use them as part of my laser work. I struggle with it because it is not second nature to me. If I’m building a cabinet or walls I still use good old feet and inches, fractions too!

When making modifications to my machine I use metric fasteners and fittings when ever possible so that I can use metric tools instead of metric and SAE tools.

Well that’s my two cents.

[Toby Hope]

whoops this thread dropped off my subscription list! thanks for the replies , so far it’s been fine on 13A (A!)

and it seems all will be good to continue, thanks for all the replies