there is no maximum as such depends on the supply type and large loads (5kw inductive loads ish) you need consent from the supply authority due to power harmonic issue's
I have seen some Transformer based mig machines on the market that say that they have an output of 300 amps for example, but require about 50 amps input on the 230v supply.
63A is the biggest BS4343 for 230V above that would be looking @ direct connection. The problem would be if that was in use in addition to other circuits (compressors, light, cooker, etc, etc) you would exceed the rating for the incoming fuse (normally 100A) ON a three phase system that load would produce massive imbalance of the phases resulting in high neutral current and the supply authority would bend you over the table for that as it would put massive strain on system
Is there any websites that I can view that has this info in writing? I need to give the Germans some proper info on what can and can't be done legally.
not that i know of as its part of BS7671 but regulation 512.1.5 "Every item of equipment shall be selected and erected so that it will neither cause harmful effects to other equipment nor impair the supply during normal service including switching operations". After that it is down to the installer to check that is compatible. Maybe contact united utilities to see what they have to say as that is a big inductive load! Probably not a case of no it can't be used but more question of when it can be used. It would need designing so that no other big loads could be used (relay interlock)
Nothin exciting, just a bigger 230v mig, at the moment we can only offer 210amp and I know we miss out on a lot of business in the rural areas, where farmers etc dont have much access to 3 ph.
Its a bit of a minefield though, I looked at a machine from a very reputable manufacturer, that claimed that it was a 250 amp out put, but the welding voltage for this would need to be abour 23-25 volts, and this machine was only putting out 19 volts, so I cant see how they can claim its 250 amps if you cant have enough voltage to get a nice smooth welding condition
I have seen lots of machines on the net that say they are 300 or even 400 amps output, but require 50 or 60 amps input supply.
The problem I have is most of mainland europe, especially Germany, can only pull 16 amps from a 230v supply, so this machine will primarily be only for use in the UK, thats why I want to be 110% sure of the facts.
as a matter of interest my last employer had a piece of plant that had a 6 MVA motor, that might dim your lights a bit on start? Not single phase I hasten to add :-)