wiring advice

[acewoodturner]

I have recently taken possession of a 3 phase Griggio panel saw and now want to wire it up. Originally it was hard wired but I want to put a plug on it as I may get more three phase machines and I can use them one at a time. The guy who is going to do the connections is a technician for an x ray machine company and has plenty of experience of this kind of job in the x ray world but not machines in the world of woodworking. The motor is 5.5hp and the cable coming of it has 4 wires and neutral. Does that then mean I have to purchase 5 core cable or 4 core armoured cable to come out of the isolator switch back to the fuse box. The salesman at Electric Centre says there isnt a lot of call for 5 core cable and would have to order it in and 4 core would do the job. I am slightly confused now as I thought as there is 5 wires coming from the machine then I would need 5 wires in the cable. There are 5 prongs in the plug and 5 in the surface mounted socket.
Any advice to clarify the matter would help me. I have to buy it tomorrow as I need to attatch it to the wall (I'm not doing any connections) ready for him doing the connecting. If I dont get it ready for him it will be another delay of a week or so as he has re arranged some work to help me out as a favour.

Mike

 

[bubbabear]

Most 3phase machines do not need a neutral, but some do, usually if they have a 240 volt control system or a 240 volt transformer for lo-vo lighting or something. In a lot of industrial situations the sockets are wired with 3 phases and a neutral and earth but the plugs only have the connections that the particular machines require. It may be you do not need a neutral but you would need to look inside the connection box on the saw to check. Hope this helps.

 

[Digit]

If you intend buying further 3 phase machines then you should certainly consider 5 pin socket outlets for maximum flexibility.
There are plenty of suppliers on Google for plugs, sockets and cable.

Roy.

 

[acewoodturner]

Thanks Bubba and Roy for your advice. I did buy the 5 core cable, plug and Surface mounted box. Another mate told me that if the machine has to be wired up using 4 cores the one of the cores in the cable I have wont be used. If I had bought the 4 core and needed 5 I would have been stuck. CEF where I bought the cable from told meon Friday they had 40m left and when I went down yesterday morning they only had 18m left which I bought. I had roughly measured out 20m and I installed the cable today with 3 or 4 feet extra at either end for my sparky to do the actual connections, so I was cutting it fine. I paid £80.00 for the cable which was about £30 dearer than my quote before Christmas! Its amazing how big a 2.5% rise in VAT affects prices!


Mike

 

[tomatwark]

The reason that you may have five core with a neutral is I guess the saw has a seperate motor for the scoring blade, this may be a 240V motor as I found on the scheppach (which has a 415V main motor) I installed at the weekend, luckly when I did the electrics in the workshop for the machines I put in five core so I could take 240v off the supplies for machine lights, power feeds etc.

If and when I move premises I will do the same again as, although the cable is more expensive it gives you the flexiblity.

Keep an eye on ebay as now and then a part drum of 5 core comes up for not alot of money, the feed cable that ws used at the weekend was bought this way and I paid about £20 for about 25m and put it in stock when I bought it about 5 or 6 months ago. I always like to have a bit of this sort of stuff just in case I need it.

Tom

 

[acewoodturner]

Tom

I hadnt thoiught of the fact that having a scoring saw on a separate motor may affect the cabling. Luckily I took my original cable back and bought the 5 core. I have installed it and the sparky will be around this afternoon to do the wiring up. I also have a pile of mdf and sterling board to cut up later this month and that what the Griggio panel saw was bought for. I have long needed a panel saw with scoring blade but also the saw has a large sliding table for sheet material and that will make handling these big sheets a whole lot easier on my own. Tonight if I get a chance I will be setting up the fence and ensuring it is square etc

Thanks for the advice Tom.

Mike

 

[acewoodturner]

Well its finally wired up! It wouldnt start despite trying all sorts of bad language . Eventually traced it to a small micro switch which shuts off the power when the guard covering the blade is moved out of the way in order to change the blade. I have left that off for now but will put it back on later tomorrow. The blade stops in about 3 seconds which is quite impressive considering my Wadkin saw used to take about 20 secs
The next task is to square off the fence which hopefully will only take 15 minutes or so. I'm just itching to use it but will hold off till everything is perfect.
I put this saw on 4 swivelling castors last week thinking that the 550Kg weight would stop it from moving too much, guess how wrong I was. I can actually move it with two fingers. I am going to have to change the front 2 for braked ones.

So, thanks for the help guys on this project

Mike