Posted By Martin Taylor Simple question do we think that for portable hand tools - chop saws, hiltidrill, grinders etc the best practice is 110V or 240v with RCD 0r is there no significant difference thanks Martin

Posted By Martin Daly The only country in Europe that thinks 110 is best is the UK. Remember its not the volts that kill its the amps. RCDs do not fail remember that if there's an RCD on the power tool there's also one on the circuit and another on the main switch board. With an RCD you do not get an electric shock. With 110 you are guaranteed an electric shock. You can use protected electric cables with 240 you can not with 110. You do not get the same voltage drop with 240 as you do with 110. Because of the lower amps with 240 much less fire risk. 110 may have been the safe option 50 years ago but the world has moved on. Martin Daly

Posted By Johno It is true that the UK is the only country that uses 110V centre tapped transformers for power tools. Volts are required to push the amps through you so at 55V, due to the resistance of the human body insufficient current will flow to kill you. RCDs do fail. It is unusual to have an RCD on a tool. Some sockets have them fitted and sometimes they are fitted in the distribution board. Many circuits do not have a RCD as it is simply not required. With an RCD, you will receive an electric shock, if you are lucky, you will be causing the current to flow from the live conducter to earth, otherwise a RCD will not operate. What is a protected cable? Voltage drop is usually not a problem as the transformers are usually within 10s of meters from the tool. lower ampage does mitigate the risk from fire only where proper maintenance is not performed. We didnt have the 110V site transformers 50 years ago and many people were electrocuted. We have moved on since then to safer working voltages. 110V is most definately safer than 240V with an RCD. If you have central 110V, it too can be RCD protected if you so desire.

Posted By Johno Assuming use indoor and not a construction site then I would say that 240V would be acceptable for a stationary machine such as a chop saw that is never moved. This is because the tool is less likely to be damaged as is the power cord. Extension leads should not be used with stationary equipment. Grinders that are moved around should be 110V as the cord is prone to damage by dragging over rough surfaces and the cord may be damaged by the tool its self. Battery operated tools are even safer but not always practical. We always buy 110V tools for our factory where there is no advantage to a higher voltage. It is worth noting that to get the benefit from 110V, the transformer should be located at the 240V socket outlet and 110V extension leads should be used to negate the need for 240V power leads. Hope this helps.

Posted By Martin Taylor thanks to everybody for their response. In answer to questions on environment the use is indoors - factory and warehouse environments. All equipment is portable - I don;t have an issue with 240V RCD on fixed equipment. Would like to use battery where feasible but not all equipment can be operated this way. thanks again for views and comments - the majority opinion appears to be for 110V but if there are other votes please shout up thanks Martin

Posted By Martin Taylor On the point of 110V transformer connected to an RCD on the 240V side - i can see that this would protect for any earth faults on the supply to the transformer but does the same go for the 110V side of the transformer or does the transformer act as an isolation device? I think it would but can the electrical clever people out there help out thanks Martin

Posted By Adam Worth NEBOSH cert text book has a good explanation of this. I'm 360 miles away from mine tho :)

Posted By peter gotch Martin. Not withstanding overall preference for e.g. 12 or 25v supply, or e.g. pneumatic tools...... The reasons why a 110v CTE supply is generally preferable to use of 240v with an RCD are succinctly set out in HSE guidance book HS(G)141 "Electrical Safety on Construction Sites". I appreciate you are not at a construction site, but the same principles apply to portable power tools in e.g. a fabrication works, where damage to cables is readily foreseeable. Regards, Peter