Pat testing 415 welding sets

[KAMAG]

Hello all.
I have been using an Ethos 9500 pat tester for about five years now. I work maintenance for a company on Tee-side. I do all the 110 volt gear and all the offices including the IT gear. When the machine was first bought it came with a couple of 415 32 amp adapters, as the plan was to also test the welding sets. The sets were never done, as i have been constantly busy with other things. It had been mentioned to me to start them but i had a bit of a niggling going on in my head. The machine can only test up to 25 amp, according to the cable calc setup and the smallest welding sets we have are 32 amp, the others being 63 amp. Now i see these adapters for sale on various pat tester sites, but can not understand how i can carry out a test on a 32 amp machine, with a 25 amp tester. is there something i am missing. I rang the guy from Ethos and he talked me through some things that i didn't quite grasp and after the conversation i wasn't convinced it could be done.
I would really appreciate some help with this.
KAMAG.

 

[jimmymac]

Do you mean the welding sets have a fuse rating of 32A & 63A?

 

[KAMAG]

Yes sorry Jim one type plug into 32 amp sockets and the bigger sets use the 63 amp sockets.
Cheers KAMAG

 

[jimmymac]

Hi KAMAG, the regs say that an earth continuity test should be carried out with a test current of not less that 1.5 time the rating of the fuse but with a maximun of 26A. As the equipment you are testing has a high fuse ratings you cannot test at a current 1.5 times the fuse as you would be testing above 26A, therefore, the test equipment you are use is suitable and and you are complying with the regs....hope this answers your question

 

[jimmymac]

I take you have checked the fuse rating within the plugs??

 

[KAMAG]

You are some sort of hero Jim. You couldn't have made it simpler. As for the fuses in the plugs, they have none, the sockets that they plug into have built in rcd's i believe.

 

[jimmymac]

Glad to be of help

 

[Patman]

I assume by reference to the plugs you mead the 3 phase commando type. These don't even have fuses fitted!!
Don't forget that testing 3 phase 415v equipment you test only earth bond and insulation - without applying mains voltage (although if you have the correct adaptors this would not be possible).

 

[KAMAG]

Thank you very much.
I will modify the settings used for 110 volt class 1 equipment, as the tester runs any 240 volt equipment during a test.

I am not sure what a commando type plug is but hopefully i have managed to attach a picture.
Inside of our adapters the three phases are linked together.
Thank you again.

I have edited my post because it just occurred to me that JimmyMac quoted what the regs said. Now i took a City & Guilds in pat testing about seven years ago and the only thing i got besides my certificate was a code of practice. is there somewhere i can get hold of any current regulations on this.

 

[jimmymac]

Isnt this covered in the IEE code of practice then??

 

[KAMAG]

Well that's embarrassing. I have just dug out my copy of the code of practice and it's just about exactly what you said, for between 2 to 5 seconds. I don't think i have looked at it more than a handful of times since i took the course. It was then two years before i was asked to start our pat testing and by the time i was asked about the welding sets, i was convinced the machine wouldn't do it. I am still not sure i would have spotted this in the booklet without your reply, as it is described in earth continuity testing, where as the tester settings say earth bond test.
Thank you very much again.

 

[jimmymac]

All answers are in the IEE books if you just take the time to read them properly, if not, just post on here and someone will answer your question for you, thats the easiest way ...lol

 

[KAMAG]

Thank you again Jimmy & Patman.
I may have just been about an hour typing this and my “jumped up, never to come down” laptop crashed and I lost the lot.
I have another question to ask and I will understand if you don't answer it, as I am not an Electrician, but a Plater.

Along with our pat testing, I make our 110 volt extension leads. The 16Amp are made from 1.5mm2 at 18 meters long.

Now when I was asked to do our pat testing, I pointed out to my boss (the company director) that some of our equipment was 19Amp and we needed 32Amp extensions for them. He wasn't very happy, we had quite a heated discussion about it and I told him to get someone else to do his pat testing, he gave in, but I think he will always hold this against me.
I made our 32Amp extensions from 2.5mm2, also at 18 meters as we had no kit above 19Amp.
We have a company that sorts out any of our electrical gear that isn't straight forward (fuse, trip etc) along with any new installation. Their boss recently said to me, that because we had a number of sub contractors now on site, they may use our kit and our 32Amp extensions really needed to be 4mm2, he may have even said 6mm2.
So before I give them the good news, I thought I would get my facts right and for the past three days have been trying to find (on the internet) cable calc software, or charts that solve my problem. However they all seem to conflict, in one way or another. It will give me AWG, or SWG and I will have to convert it. Or it will give me mm, so I am not sure if they mean mm diameter, or mm2.
Can you point me to any formula or chart that will solve my problem. I have looked at Lenny's Super Moderator template on this site, but it is too complicated for me.
I found what I thought was an excellent formula at h**p://www.smartgauge.co.uk/cable_type.html but then came to the conclusion that I needed to double the length of the cable for the formula, which then made my required size 10mm2.
Thank you again.

 

[telectrix]

your 19A equipment needs to be connected to a 32A socket, as it's above the rating for a 16A socket. however, the cable size for the leads does not need to carry 32A, it's only required to carry the load of 19A, so 2.5mm cable is adequate. (volt drop permitting).

 

[sevifoley]

your 19A equipment needs to be connected to a 32A socket, as it's above the rating for a 16A socket. however, the cable size for the leads does not need to carry 32A, it's only required to carry the load of 19A, so 2.5mm cable is adequate. (volt drop permitting).

If you are installing a 32A plug to an extention lead, the cable should be rated to carry 32A, the item you are using it for now is 19A, but what will it be used for in the future. Once the extention lead is made and in service, knowbody will care about the cable size because they see a 32A plug on the end and asume it is rated to 32A.