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Old 15th Sep 2018, 10:30 pm   #16
Skywave
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Join Date: Jun 2006
Location: Chard, South Somerset, UK.
Posts: 7,457
Default Re: Lamp limiter plus Variac tip

Quote:
Originally Posted by Red to black View Post
Hi Alan, Electrical separation (isolation transformer) and RCD are two different protective measures, there is little point in using an RCD with a fully floating supply as it won't detect an earth fault because there is no potential difference wrt to Earth.
A thought following from that. Choose a mains isolating transformer with 115-v. / 0v / 115v. secondary. Route the two phases of the 115-v. through an RCD to a 3-pin socket (one phase to 'L', one phase to 'N',) with the 0v. to its 'E' pin. That 0v. is not connected to supply earth. That 'earth' wire connects to metalwork of the load. We then have a balanced bi-phase supply of 230-v. for the load with RCD protection.

Al.
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