Electric Questions

[madkayaker]

and be carefull when your puliing those fuses out that there is no fuse wire pokeing out over the to and there very slippery and will brake if you drop them

 

[brightspark]

hmmm thats different, it used to be a whole complex with multiple units owned by one company. Like i was saying there is another fuse box and meter at the back of the workshop. Its one single meter and looks a more modern unit however it only spins when using certain parts of the workshop and does not appear to link anywhere near the other meters.

With the setup i have does this mean i have a supply thats branched off from a supply that not located in the workshop. This may get confusing.

look where the electricity boards supply comes on to the premises there will be a 3 phase cutout. in laymans terms 3 large supply fuses then within 6inch will be either a 3 phase meter or 3 old type single phase meters and from them in to an isolator and in to a 3 phase db . as said your other supply is a sub mains supply

 

[andy82]

thanks for the help madkayaker, how will i know how many amps my supply is getting. Is this a job for an electrician or would there be any markings or rating on fuses etc.

 

[andy82]

Thanks for the info brightspark i will have a better look

 

[andy82]

I will say that the workshop is part of a large complex of other units owned by one company, not that i have been told this but i presume they are running the mains and will bill the tenants. The company own a large series of offices attached and units scattered around. It used to be a large engineering company.

Since moving in i have not met the landlord yet as he is on holiday and have only dealt with the letting agent and they dont know the situation with the electrics.

 

[madkayaker]

Depends on where the switch gear is. It might just be in a cupboard on the corridor etc in in a plant room. The fuses will tell you the current. Fro the looks of the cable in the meter it might not be that big but it's hard to say. Where in Scotland are you?

 

[andy82]

Would it be enough to run the 320a thermal arc (Safely)

I will have the following to run, at any one time

Spray booth with fans (powder booth and blasting)
Oven With 4x 3000watt heating elements
Compressor
Plasma cutter
Welder
Saws
Lighting and computers

Nothing large scale mostly the welder and P/C oven

 

[madkayaker]

Impossible to say without seeing the installation

 

[andy82]

is it possible for me to test the 3 phase using a multimeter from the socket on the wall, i understand the process for single phase but unsure what reading to expect, without seeing the wires from the socket i am unsure what prongs to test.

Is this something that should be left to an electrician, I had quotes of £80 to check the socket just to see if its safe to plug in my welder.

 

[madkayaker]

Please don't take this the wrong way but if you have to ask should you be doing it? Phase to phase about 400-450V Phase to Earth 230-250V.

 

[andy82]

You are right i should not be doing it, it should be an electrician but for a few minutes to check i have had some silly quotes. Would you believe i had a quote of £120...lol

sorry for the persistent questions just anxious to start working and i want to do a review on my new thermal arc welder.

I will phone round a few more places tomorrow.

 

[rtbcomp]

Did you read post #2?

 

[KemppiFrog]

Think you need to talk with the letting agent/owner. If you rent a space, surely the lecky should be up to spec? And, if not, they need to sort it.

 

[andy82]

Thanks rtbcomp, i remember that post. I would possibly be a bit nervous trying that myself.

Kemppifrog the landlord is on holiday but did speak to the landlords father in law and they said they will do an inspection soon and replace the handle on the cutoff box. I was unsure if i was responsible for the 3 phase or not. My understanding was the landlord was reasonable for everything up to and including the fusebox and i was responsible for any sockets etc

 

[brightspark]

the 3d fuses along on each phase in the db . red yellow blue is the feed for the 3 phase socket its marked on the chart . a simple test at the socket pins with a multimeter will tell u that all 3 phases are there. as was said across the phases will be aprox 415 to 440 v and phases to neutral will be 220 240v providing your welder has the correct plug to match the socket your in buisness

 

[andy82]

Great thanks for the help everyone, Hopefully if all is well i will post a review on the new TH/ARC Welder. Good quality unit and for the price i paid you would struggle to get a similar spec and comes standard with 4 roll wire feed.

 

[Feanor]

thanks for the help madkayaker, how will i know how many amps my supply is getting. Is this a job for an electrician or would there be any markings or rating on fuses etc.

Ask the power company. You might have to chase about a bit on the phone before you get someone technical with that knowledge. Now there's been de-regulation it may be that the people you pay your bill to aren't the ones who own the equipment and who will know these things. Maybe not in Scotland though if it's Scottish Power and always has been.

The fuse rating of the main fuses won't be exactly the amount of power you are receiving. They'll obviously be rated higher than that, otherwise they could be blowing regularly. I have 4 main fuses (there's one for the neutral too) and they are rated 100 amps each. The power company told me I have 80 amps per phase incoming.

 

[Feanor]

Obviously be really careful but using a good multimeter, set the voltage range on the machine to AC volts incorporating 400+ volts within the scale. It may be you have to set the range to 0 - 1000 volts AC. 0 - 500 volts would do it if there is such a scale on the meter.

Test each phase between itself and neutral. It should read around 230 volts for each one. Do the same test between each phase and Earth too. The readings should be the same.

Then test each phase against one other live phase. This should read around 415 volts. So it's 415v between Red and Yellow, Red and Blue and Blue and Yellow.

Do NOT try to test the amps with a multimeter under any circumstances.

 

[madkayaker]

Ask the power company. You might have to chase about a bit on the phone before you get someone technical with that knowledge. Now there's been de-regulation it may be that the people you pay your bill to aren't the ones who own the equipment and who will know these things. Maybe not in Scotland though if it's Scottish Power and always has been.

The fuse rating of the main fuses won't be exactly the amount of power you are receiving. They'll obviously be rated higher than that, otherwise they could be blowing regularly. I have 4 main fuses (there's one for the neutral too) and they are rated 100 amps each. The power company told me I have 80 amps per phase incoming.

He is not connected directly to the DNO supply so ringing the DNO will be no use

 

[Feanor]

Ah yes of course. They can still tell him the power going to the premises as a whole.