2Brix Posted January 25, 2020 Share Posted January 25, 2020 Hi folks, I'd like to know how a 100V Japanese turntable should be earthed/grounded within a 240V system, i.e. with a system where......... 240V wall outlet powers --> stepdown transformer powers --> 100V turntable 240V wall outlet powers --> 240V phonostage .........should the earth wire be a) hooked up from turntable 'ground terminal' to a ground terminal on the transformer outlet side (100V side). Note: i haven;t seen this transformer so i don;t know whether they actually have grounding terminals ?? b) hooked up from turntable ground terminal to the transformer inlet side (240V side) ? c) hooked up from the turntable ground terminal to the phonostage d) all of the above Just kidding about d)...... Cheers Ed Link to comment Share on other sites More sharing options...
eman Posted January 25, 2020 Share Posted January 25, 2020 Pretty sure I had option C in the situation you describe. Link to comment Share on other sites More sharing options...
t_mike Posted January 25, 2020 Share Posted January 25, 2020 Are we talking about the earth wire from the tonearm, or the earth wire from the power supply cord, or both? Completely different answers for each. Link to comment Share on other sites More sharing options...
Warren Jones Posted January 25, 2020 Share Posted January 25, 2020 (edited) I have a Technics SP10 that is Japanese, so no mains earth in the power lead from the TT power supply. If your TT is not double insulated like mine you can use a 3pin mains plug and just connect earth wire to TT and earth pin in plug and plug into power point. BE VERY CAREFUL IF YOU DO THIS NOT TO CONNECT EARTH TO EITHER ACTIVE OT NEUTRAL. Edited January 25, 2020 by Warren Jones Link to comment Share on other sites More sharing options...
Wimbo Posted January 25, 2020 Share Posted January 25, 2020 If your step up tranny is 3 pin then all should be good. If you are talking about the earth on the Tonearm cable then C is the way to go. Link to comment Share on other sites More sharing options...
2Brix Posted January 25, 2020 Author Share Posted January 25, 2020 Thanks all for the replies. Yes i'm asking about the earth wire on the tonearm cable. If i have a 240V turntable and 240V phonostage i would naturally use option c) However i was bit unsure whether #exactly the same would be correct for a 100V turntable paired with a 240V phonostage. I'm a nervous nellie and rather like Catweazel when it comes to electrickery I'll double/triple check the earthing (grounding) arrangements when i get to see the actual turntable and transformer. Link to comment Share on other sites More sharing options...
Guest Muon N' Posted January 26, 2020 Share Posted January 26, 2020 'C' Link to comment Share on other sites More sharing options...
rodders3 Posted January 26, 2020 Share Posted January 26, 2020 Yep, 'c' for me. Link to comment Share on other sites More sharing options...
Decky Posted January 26, 2020 Share Posted January 26, 2020 Why do you think that mains voltage should define grounding for any device? Link to comment Share on other sites More sharing options...
Warren Jones Posted January 26, 2020 Share Posted January 26, 2020 Even if the transformer has a 3pin plug the TT will not so the TT chassis is NOT grounded. If the TT is not double insulated (indicated by a box in a box on the power label) the chassis must be grounded to mains ground, otherwise if you have a fault in the TT the mains breaker most likely WILL NOT TRIP, eg the active shorts to the chassis and you touch the chassis you might not get second chance. All Japanese gear I have seen does not have an earth wire. When I worked at Marantz they bought a heap of old Jap stock and I had to replace all the power cords with 3 wire and earth the chassis these were all amps. For TA ground yes C Link to comment Share on other sites More sharing options...
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