3 phase PAT adaptors

[Patman]

Anybody out there still need info on 3 phase PAT adaptors?

 

[ringer]

What info do you have to share?

 

[Patman]

Well for starters - its most important that PAT adaptors for 3 phase equipt. do not allow a mains connection (inadvertantly or not) from the PAT testing equipment. So the first thing you do is snip off the "live" wire from the cable where you're going to terminate it into the adaptor. Next step connect earth (doh !!), then Neutral into first phase conection. Each subsequent phase is then looped together into the first. - see picture I've taken.
PAT testers are configured to apply insulation test voltage to both Live & Neutral, therfore it don't matter the "Live" is snipped off.
All of this is covered in Code of Practice page 76 Para 15.5 notes 4 & 5.
I set my Supernovas up to carry out this test and is listed separately on the test menu.

 

[ringer]

I would not, and have not, snipped off the live on my adaptor. Two reasons for this. Firstly, there is no safer way to terminate a cable other than secure it into the correct terminal. Second, all such PAT adaptors are under the careful supervision of a competent person (that's me) and will only be used in conjunction with the correct equipment (my PAT tester) and will be utilised appropriately (by me). I have not yet made up all of my 3-phase adaptors, but have detailed on this thread how I intend to do so.
I see why you have done this snipping, but think it is both unnecessary and unsafe. I would question how appropriate it is that your tester is putting 500VDC out on both phase and neutral pins, but there is no conduction on the phase. Would this possibly harm your PAT tester? But at the end of the day, you do it your way and I'll do it mine. Just out of interest, have you snipped off the brown at the 13amp plug as well?

 

[amitch]

Now i'm confused ive just purchased two adaptors both from different suppliers and they are both wired differently one has all the phases wired through the neutral of the plug and linked, the other is wired through the live of the plug and linked. Which is right? Any help would be appreciated

 

[ringer]

They are both right, in as much as an IR test applies the voltage on both the live and neutral pins simultaneously. But I do not agree with either of these methods - I connect all lives together in the plug with live from the 13amp plug to L1 and links from L1 to L2 and from L2 to L3 in the 32amp socket, and then neutral to neutral. Can you share the names of the manufacturers of these adapters and show photos of the connections?

 

[Patman]

Hi amitch -

if you recap my post above you'll see one of the adaptors you have is as described. With regard to the connection of the "live" from the 13A plug, it must be remembered, particularly from a supplier that distributes product widely, that risk should be eliminated rather than reduced.
Therefore by using an adaptor so configured you are demonstrating to your client you can test for safety purposes, 3 phase equipment. We all know the catastophic results of inadvertantly applying 230v single phase. You can then prove to your customers that your PAT testing does not (or have the potential to) damage their 3 phase equipment.

 

[ringer]

... We all know the catastophic results of inadvertantly applying 230v single phase....

I for one am not aware of catastrophic results occurring when single phase 230v is applied simultaneously on L1,L2 and L3 in a 3ph appliance. I would have thought the worst thing that will happen is that the 3ph motor will stall.

Now if it were a (single phase) 110V appliance that had 230V applied to it, I could understand that being not in the best interests of the well-being of the appliance....

 

[amitch]

Hi Ringer/Patman
One of the adaptors has had the live snipped off and also the fuse has been removed from a moulded plug with the fuse holder silconed in so that it doesn't fall out, this is made by Martindale.
The other adapter has had the neutral snipped off and the live is linked which as stated previously its the live that cause any problems. I guess its up to me to make the decision which way to go with the adaptors

 

[Patman]

Thats what I expected you'd find - hence inhibiting the "inadvertant" application of 230v single phase.

 

[septeluna247]

Just finished making all 4 of mine up. Was going to buy them ready made but after reading this thread and now understanding 3 phase a lot more i have made my own. A good learning exercise and saved about £75 too!! Many thanks to all the contributors on here.

 

[Graham Abbott]

Hi, Sorry I'm a bit late to this party, but if anyone is still watching:

If you disconnect the live lead, and there is a break in the appliance circuit, such as an immobiliser or even in the lead (someone is only using a 240v offtake but the 3 phase socket is still available to use), then is is not possible to have a significant portion of the circuit untested?

My Metrel tester would certainly return an error code indicating excessive resistance between live and neutral (suggesting that the appliance was not switched on).

Appreciate the info, though, well presented. Ta.

 

[i=p/u]

Well I can't see the point in snipping it, I thought the tester shorts out for you so all you have to do is link the lives(brown ones) lol

 

[i=p/u]

And I thought because ate linked it splits=250 v down L and N

 

[stoneworld]

interesting....
My home made 3 phase test plugs are wired E-E N-N L-L1+L2,L3. I have a 13A to 3ph and 3ph to IEC in 125A down to 16A along with single phase, Powercon, SOCAPEX, 15A Round pin and 110V 16A. That's a lot of money in plugs!
the question I have is that if you should remove the live in a 3PH plug to make it idiot proof, how would you go about wireing a 110V 16A Plug and socket? If you remove the live in this you can't test extension leads....

 

[Patman]

Surely 110v 16A plug & socket are single phase, therefore your extension leads made up with these are tested as a "230v" extension -except in 110v mode.

 

[stoneworld]

Surely 110v 16A plug & socket are single phase, therefore your extension leads made up with these are tested as a "230v" extension -except in 110v mode.

yes, that's how my test leads are made, 13A Plug to 110v 16A socket L-L, N-N, E-E but the point I was trying to get over was that in the 3PH test plugs they have removed the live so you can't attempt to power a 3PH device from a single phase but in a ready made 110v test lead do they do the same because you could plug a 110v appliance into the test lead and give it 240V.

my test leads are clearly marked up for PAT only and I wouldn't let anyone else use them but the danger is still there.