hi john, you are similar to us here in the uk. the only diffirence is that you are 60 hz and we are 50. but that wont make any diffirence in what you want to do.
from my point of view, if it were me i would run in at least a 30 amp radial circuit (sometimes known as a sub main, but you may consider a 45 amp sub main to give you capacity for further development. from this you can then take of a 20 amp dedicated circuit for the saw and dust extractor, and a further 15 amp circuit for your heater, and a further circuit for your lights. not sure what you are allowed to do in australia as regards the size of cables, but what you need to take into consideration is the distance away from the supply line you are going to run your saw. because the further away you are, the more cable you need to use, and the more the voltage drop will be under load. for cost effectiveness, for a short run of cable under 5 metres, it will probably be cheaper and easier for you to run in your sub main with a 6mm twin and earth cable. similar to what you would put in for a small electric cooker or a 8.5 kw electric shower. however, if the run is extrimely long you will need to use a 10mm cable, as this will have less voltage drop, and allow you for future expansion. your saw and extractor will draw maximum load on start up, and going on the figures you gave me this will be around 14 or 15 amps, but you will be right at the limit of your fuze if you put in a 15 amp breaker. so this is why i would put in a 20 amp on this circuit. it all depends on your heater, but if it is a 3 kw heater, you will need a further 15 amps for this. and your 6 lights will need around 5 amps. so adding this up, you have the potential to use around 35 amps when evrything is on. so for safety sake and allowing for future development, your instilation should be capable of taking around 45 amps on maximum load, so you should fuse your isolator switch accordingly. giving a choice i would get your spark to put in a 4 way board close to your saw, fused as follows. a 20 amp for your saw and extractor, a 15 amp circuit for your power outlets and a 10 amp circuit for your lighting. the spare would be for future development such as drills and other power tools. the other thing to take into consideration is how are you going to run your cable. is it overhead, or is it underground. there are specialist underground cables for this job, you can use what we call pyro, this is a special cable with a solid copper outer which is used as the earth conductor, but may not be a good idea if you are putting it anywhere it can get damaged. it also needs specialist crimping tools to make the ends. my choice for underground would be either steel wire armoured, or twin pvc hi tuf. if you are not sure what these are, please ask me for more details. best of luck, and if there is anything you are not sure off, please email me back. Dave & Sally. buy and sell your surplus free, join the new mailing group by sending a blank email to. [EMAIL PROTECTED] or find more details here. http://www.secretsthatwekeep.com/thebargainstore/invite.htm ----- Original Message ----- From: John M To: blindhandyman@yahoogroups.com Sent: Friday, September 14, 2007 9:35 AM Subject: [BlindHandyMan] 240Volt, 15Amp power supply for 3HP Table Saw+1½HP dust extractor. G'day Dave & Sally, John in Melbourne Australia here, I'm also a newboy to the list and I have enjoyed reading your, and all other Blind Handyman posts. Good luck with that new lawn and petrol mower. Here, because we've been in severe drought for 10 years, I'm digging up my old brown weed crop and re-planting the front garden with flagstone! :) Dave, in a month or so I'm taiking delivery of a 10 inch, 3HP induction motor Cabinet Saw and a 1½Hp dust extractor. They'll be set up to start together at switch on, and at switch off the Cabinet saw shuts down, while the dust extractor continues to run, on a time delay, for a further 30 seconds or so. Thus at switch on I'll be trying to pull 4½HP, or approx 3,350Watts through my household wiring. Moreover, if I should happen to have a sighted mate working with me at the time, and it's Winter, then I'll also have 6 fluorescent light tubes and an electric blow heater running. Here, in Australia we're just like the UK and run a 240Volt 60hZ electrical power system, and all standard household power outlet sockets and plugs are 3 pin. The household lighting circuits are rated at 10Amps and the power circuits are rated at 15Amps. I don't know, but I think the safety switchboard is designed to trigger shutoff at 15Amps. I certainly remember as a kid having to replace burnt out 15Amp fuse wires for me old Mum. It was usually on wash days in mid Winter while she was doing the family Ironing, running the washing machine, the clothes dryer, the 2bar electric radiator while watching the Telly and making us kids cheesie toast under the electric grille. And, mostly all of this power was taken off 1 power point with several piggy-backed double adaptors! :) OK Dave, so my questions are, what do I need to get a Sparky to do in my garage to avoid similar overload problems? Would 1 dedicated 15Amp circuit be sufficient to run my Cabinet saw & dust extractor, or should I get 2 separate dedicated 15Amp lines put in? Or, perhaps I should ask for a dedicated 20Amp line, or two to be installed? :) As you see from my words, while I'm OK at cutting, moulding, bending and shaping wood to my will, when it comes to electricity, I'm a total drongo. Thanks Dave, any advice would be much appreciated...see you in the Soup, John M Melbourne Australia. From: dave and sally To: blindhandyman@yahoogroups.com Sent: Thursday, September 13, 2007 6:28 PM Subject: [BlindHandyMan] electrical safety when plumbing with plastic hi all, forgive me as a new kid on the block for telling some of you how to suck eggs, and what i am about to point out may not apply in north america or canada, but it certainly applys here in the uk where our supply line is between 230 and 240 volts. so in case someone is on the list that this may effect, i feel i should point out a potential hazard of using plastic pipe. living in northern ireland, we have used something similar to pex for a few years now. however there is one big disadvantage in using plastic piping of any kind, especially in europe. i am not sure what the situation is in north america with the electrical supply, do you use an electrical earth connection? and if so how do you get this connection? i know most of your supply lines are around 110 volts, and in some cases for cookers or stoves it may be in the region of 240 volts, but here in this part of the uk all our appliences that have a metal frame must be connected to an electrical safety earth. for those who dont know what this is, it is a common wire that connects to the frame of evrything metal that has an electrical supply throughout the house. this includes dish washers, washing machines, stoves, water heaters and centeral heating, centeral air etc. this is to allow a faulty applience to be able to blow a fuze or trip before it kills someone. now if the wireing has been done properly, there should be no problem, but the potential for electrical shock is high if someone who doesnt know what they are doing comes along and does a bit of handy work either to the plumbing or the electrical instillation. heres why. because all appliences and instilations with metal caseings need an electrical safety earth connection attached to them, here in the u.k. it is regulation that all metal pipes throughout the building is bonded together with at least a 6 mm copper wire. as i said earlier, if this is done properly and left alone , there should never be any problem. this is because on modern instillations the earth is taken from the supply cable at the meter board, and is common with the neutral return wire. however on old instillations, especially in the country areas where overhead supply cables are a common sight, more often than not the earth return path is made by either an earth spike, which in some instances is just connected to the water pipe at the point where it entered the house, or dread the thought, even by just relying on the old water main itself, which in days gone by was either copper or lead. this worked well for many years, that was untill someone invented plastic pipe. because by breaking the continuity of the earth by replaceing a piece of damaged lead or copper pipe with plastic, they take away the safety aspect of having an earth connection which goes to earth, and subsiquently back to the municipal supply. in lots of cases this was never noticed untill someone developed a fault on the system. lets say you got a falty water heater that decided to short to the copper cylinder that it was enclosed in. if the earth was working properly, this would normally blow the fuse or trip switch. however because it now cant find a path back to earth via the old copper or lead pipe, it just sits there and looks for the path of least resistance to earth. hopefully this is not you! the applience may still work, however because the pipework in the house is acting as an electrical conductor, evrything else in the building on the household side of the plastic join will become live and have the potential of causing serious shock or death. this can happen if you dont know there is a problem and you grab onto something metal, such as your cooker or sink. or if you disconnect any of the metal pipework at your hot water cylindar that is not cross bonded to all the other pipes that are close by. this is only a couple of sinarios, there are of corse many other instances on how electrical shock can happen if there is not the proper care taken. there is of corse an easy resolution to this potential problem, and that is should you ever have the need to replace a piece of metal pipe with plastic, you should also run a piece of 6 mm earth wireing along side it, and clamp it to the metal pipe on each side of the join. this ensures that the earth protection is not broken. however if you are not sure where you get your earth supply from, just in case there is a fault that may not be evident, if possible you should consider switching off your electric supply when replaceing a section of existing metal pipework with plastic. on no account should you grab on to both ends of the old pipework with both hands once it has been cut. as i said earlier, forgive me if this does not apply to you, but it certainly will apply in some countrys throughout the world. it is known for a voltage as low as 50 volts to cause serious damage to anyone who is not in good health, should they get it going to earth across their chest. and if you must work on wireing that is live, do it with the knowlege that electricity is silent but deadly, so always have someone else around you when you are doing this.. heres a safety quote from a sparks point of view. its the volts that jolt, its the mils that kill. be safe, stay safe, and ask questions before you start working with plumbing or electric. i can answer any questions on this subject should you wish to ask them. best wishes to all, Dave & Sally. 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