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Isolation transformers http://www.dcaudiodiy.com/phpBB3/viewtopic.php?f=5&t=1216	Page 2 of 10

Author:	ratbagp [ June 24th, 2018, 2:12 pm ]
Post subject:	Re: Isolation transformers
The specs of the Hammond unit talk about producing noise and not suitable for an office environment. ray

Author:	SoundMods [ June 24th, 2018, 2:40 pm ]
Post subject:	Re: Isolation transformers
Jay Bala wrote: Here is another one for consideration: https://media.digikey.com/pdf/Data%20Sh ... lug-In.pdf There is no lack of choices -- the computer industry has been using isolation transformers for decades. When I did design/build of computer data centers I purchased the "family size" versions as large as 75-kVA.

Author:	TubeDriver [ June 24th, 2018, 11:16 pm ]
Post subject:	Re: Isolation transformers
20lbs seems a bit light for a 16A 2000W unit? My 15A 1800W Bryston weighs almost 50lbs. But that is a killer price on your unit! ratbagp wrote: It is quite a monster and weighs 20 lb. When it arrives I will take the lid off to see what is inside and take some photos. Then I will ask for suggestions on how to improve it. ray

Author:	SoundMods [ June 25th, 2018, 8:37 am ]
Post subject:	Re: Isolation transformers
TubeDriver wrote: 20lbs seems a bit light for a 16A 2000W unit? My 15A 1800W Bryston weighs almost 50lbs. But that is a killer price on your unit! ratbagp wrote: It is quite a monster and weighs 20 lb. When it arrives I will take the lid off to see what is inside and take some photos. Then I will ask for suggestions on how to improve it. ray Your Bryston is stuffed with a lot more than a power transformer. The heat sinks alone can run up the weight. Keep in mind that an isolation transformer is just that -- only a transformer.

Author:	ratbagp [ June 25th, 2018, 8:47 am ]
Post subject:	Re: Isolation transformers
I went back and looked at the spec sheet and it says 19.1 kg or 42 lb. Not sure where I got the 20 lb but maybe I misread the specs. ray

Author:	TubeDriver [ June 25th, 2018, 4:42 pm ]
Post subject:	Re: Isolation transformers
ratbagp wrote: I went back and looked at the spec sheet and it says 19.1 kg or 42 lb. Not sure where I got the 20 lb but maybe I misread the specs. ray That sounds more like it! Basically $1 per lb! Good deal!

Author:	ratbagp [ June 28th, 2018, 11:32 am ]
Post subject:	Re: Isolation transformers
A very heavy box was left in our driveway, courtesy of FedEx. I suspect the shipping cost more than the $40. Unwrapped. I should be able to provide some sort of handle. The box weight was 45 lb. That is a fair sized toroid. The outlets look heavy duty. Toroid label. Fuses. Fuses I noticed that the ground lug was not connected to the case. In addition, the yellow / green shield wire is disconnected. I would like some advice on whether to connect the shielding wire to the case at the same point as the grounding wire. I have not tried it out yet and will wait until I fix the ground issue. Then I am open to suggested improvements. We usually eat outside during the summer months and a pair of these brightly coloured butterflies visit us each evening during the meal. In their honour, I am naming the power conditioner 'the butterfly'. ray

Author:	Stuart Polansky [ June 28th, 2018, 12:39 pm ]
Post subject:	Re: Isolation transformers
Yes and yes to ground lug and electrostatic shield termination points. Please ensure your home grounding system is in good shape. Assuming you have only one circuit breaker panel, within which is contained the "main bonding jumper", (Aka neutral bar), the grounding and grounded conductors should all terminate at this point. Check tightness of connections. Check the receptacles and other devices, upstream of the receptacle you intend to connect to. Make sure connections are made by screws and not "stab-in" leads. If you can, go buy some better receptacles for the circuit, NOT contractor or residential grade. Ideally "hospital grade", but "industrial grade or "commercial grade" should suffice. Better receptacles will have clamping means to secure circuit conductors, as opposed to screws, around which one winds the conductor. Better receptacles also have larger area of contact between blade and receptacle surface. Wanna REALLY do the best you can? Use #10/2 AWG MC cable from circuit breaker panel to a separate circuit receptacle. Use a twenty ampere hospital grade receptacle (Only use on a 20A circuit), and use a 20A circuit breaker. As to the transformer: The receptacles in the isolation transformer enclosure are Nema 5-20R, which are indeed heavy duty. The fuse holders look to me to be poor in quality, along with those spade connectors. Going against my usual advice, I'd bypass them. Here's the thought process. If you use this device on a 15 ampere circuit, then 1800VA is the most power available through the unit. Fuse should be unneeded. The receptacles, rated 20A, are good for 2400VA at EACH receptacle (4 total). No failure is likely there. If you use this on a 20A 2400VA circuit, you might overload it, but situational awareness of the device's use in your possession should keep you safe and sound. Nice find, best of luck with it. Please keep us posted on any real and imaginary sonic improvements from using it. :lol: Stuart

Author:	ratbagp [ June 28th, 2018, 1:16 pm ]
Post subject:	Re: Isolation transformers
Thanks for the advice and I will do a checkout of the electrical system. The receptacle that I will be using is an expensive floor model so I can't change it but it has always felt very sturdy. I have already fixed the ground problem. The screw holding the ground lugs had broken off so it was a simple replacement. Now I have to find a suitable handle. I had wondered about the need for the 20 amp fuses given the 15 amp limit in my fuse box. I will report back in a few days about my listening experiences. ray

Author:	SoundMods [ June 28th, 2018, 7:02 pm ]
Post subject:	Re: Isolation transformers
I would suggest that removing the ground tabs was not done at the factory. It appears that the electrostatic shield connecting wire was disconnected. I would locate a fastener to replace the one missing and reconnect those wires as intended by the designers.

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