32A to 16A 3 phase question

[john87]

3 hours ago, GarethM said:

Yeap, it made life easier than explaining 3 phase to people.

 

We had a green light in the on/off switch mechanism too, so it was either green for go or red for no!.

Very good idea!! I take it you used to sell machinery or install it??

 

john..

[GarethM]

8 minutes ago, john87 said:

Very good idea!! I take it you used to sell machinery or install it??

I still sell & repair equipment and have moved almost entirely to single phase and transformer driven electronic BLDC type motors without any real loss in power.

 

Usual HSE type of thing, even now people seem to be gravitating even further to 110v.

[Dilz]

PCE 9436422 CEE Adapter 32A-16A

WWW.THOMANN.DE

---

CEE Adapter 32A - 16A Mobile plastic distributor, type St. Anton-2f IP44 with bracket, 1x CEE connector 32 A 5p 400V...

 

Using one of these seems a legit way to go about it.   

 

Would it make sense to pull this in to the 32A outlet and then run a 16A cable to the machine or would a 32a cable be best to run from the outlet? Going to need about 30 - 35m of cable I reckon. 

 

 

 

[GarethM]

Might be easier to just get a spark to put a socket closer to the work area.

 

Preferably keeping extension leads to less than 10m is preferable.

[Dilz]

That's not really an option.  My patch is about 25m away from the main building.  There's 3 outlets on the outer wall.   

[GarethM]

Fair enough, how much power do you need ?.

[Dilz]

will only be running one machine at a time - so  just a single 8kw motor - any more info than that id have to look up. 

[john87]

48 minutes ago, Dilz said:

PCE 9436422 CEE Adapter 32A-16A

WWW.THOMANN.DE

---

CEE Adapter 32A - 16A Mobile plastic distributor, type St. Anton-2f IP44 with bracket, 1x CEE connector 32 A 5p 400V...

 

Using one of these seems a legit way to go about it.   

 

Would it make sense to pull this in to the 32A outlet and then run a 16A cable to the machine or would a 32a cable be best to run from the outlet? Going to need about 30 - 35m of cable I reckon. 

 

 

 

 

As i think Gareth is about to mention, the extension lead is not going to be that simple and you really need to get an electrician with a brain involved. That is a very long run.. It is NOT NOT NOT, just a question of getting a "16A" extension lead..

 

You see, at that length of run, EFLI and volt drop are going to be the governing factors for the following reasons..

1, If the volt drop is too high, the motors will struggle to start if they start at all.

2, If EFLI is too high, in the event of a fault, the breakers will either trip too slowly or not at all. Either way, it will result in damage or electrocution..

 

I once sold a compressor to a farmer They connected it to a very long run of 2.5 twin and earth, The thing barely started...

A few days later, said farmer turns up all irate.. I go and have a look, and what had happened, is the motor had failed to start. As it was such a long run of cable, even though there was effectively a dead short, the "circuit" could not pull enough current to trip the breaker, so the power stayed on and the whole lot got hotter adn hotter until the motor had literally melted into a blob of aluminium and copper..

 

You see, a circuit breaker is selected to suit the load.. THEN a cable is selected on the basis of Volt drop and EFLI, which means that you could need a cable suited to, say, 70A for your 16A load..

 

Tell us exactly what it is you want to run and we can advise further..

 

john..

[GarethM]

@john87 pretty much was going to be my next question as extension leads say 4mm+ get very pricey and liable to get damaged.

 

Any chance you could bury SWA closer to the job ?. The cost of a short extension would be peanuts 😀

[john87]

26 minutes ago, GarethM said:

Fair enough, how much power do you need ?.

Hi Gareth,

 

Ok, an 8kw motor, so that is 8000/1.732/400 = 11.5A but then guessing PF .8 and efficiency 90%  just over 16A ??

Then you would need an allowance for starting currents..

 

Pretty big cable??

 

john..