Mains earth?

[Yivez]

After too long, we are finally updating the electrics to our house.

I have always struggled with amplifiers and transformer hum. I use a Puritan PSM136, which goes a long way to reducing issues but not entirely.

The electricians discovered the main Earth line was not up to the job. They will install a new earth rod and earth line. Is it worth seizing the moment and taking another feed from the earth rod to my listening room ( ~4 metres distance) and using one of the many ground products from Puritan and Russ Andrews? Does anyone have any experience doing this?

 

[kernow]

Unsure about the rest but don't give Russ any money pls

 

[pocketkitchen]

Only if your properly qualified electrician says it’s safe to do so… I have no comment to make on any sq issues - you’ll just get people arguing. Transformer is usually caused by dc on the mains though, from my understanding. I’m not sure earthing affects this.

 

[GT]

Thing is that the earths in your mains sockets will be wired back to your new earth rod so I can't see the point of running a separate earth to a RATA socket with a 4mm earth post fitted. You are more likely to encounter hum issues if you do anything that does not meet the electrical safety standards and approved codes of practice.

 

[turbo al]

If upgrading the earth then there really should be no need to do anything more earthwise, the new earth will be the same throughout the property including in your listening room. A seperate radial feed(s) to your listening room however, is another matter.

GT beat me to it

 

[Mike Reed]

A separate radial feed(s) to your listening room however, is another matter.

Presumably you're on a TT earth (local to the property rather than back to the grid). Really, improving or replacing (as here) your earthing is beneficial and a lot safer. A radial circuit for your hifi is, of course, very useful indeed but to be done properly, you'd need a separate consumer unit etc, in which case you might as well have a number of radials.

If then you want a dedicated earth (but only with TT earth), then fine. Otherwise, I feel that your sparks is going to frown at adding another to (presumably) a ring main socket; bit pointless at best, i.m.o. Not sure the upgrade will reduce hum (from toroidal trannies?) but certainly shouldn't be worse. A full-blown radial system can be cost effective sonically but only with decent s/s kit, i.m.o; and Naim, of course !

 

[Rug Doc]

No need for the extra earth Rod.

Just buy hifi with decent power supplies.

 

[Yivez]

Presumably you're on a TT earth (local to the property rather than back to the grid). Really, improving or replacing (as here) your earthing is beneficial and a lot safer. A radial circuit for your hifi is, of course, very useful indeed but to be done properly, you'd need a separate consumer unit etc, in which case you might as well have a number of radials.

If then you want a dedicated earth (but only with TT earth), then fine. Otherwise, I feel that your sparks is going to frown at adding another to (presumably) a ring main socket; bit pointless at best, i.m.o. Not sure the upgrade will reduce hum (from toroidal trannies?) but certainly shouldn't be worse. A full-blown radial system can be cost effective sonically but only with decent s/s kit, i.m.o; and Naim, of course !

Thanks for all your comments and yes a local earth dedicated to the property. I am just going to run with this new earth install and a new fuse board etc and no other work specific to Hifi. I will find out if there are any improvements pretty quickly as they make start on Wednesday.

 

[Ian G]

Hopefully they'll be installing rcbo's on all circuits with an upfront (S) type, time delay, incommer rcd ?
If a jobs worth doing etc.

 

[Rug Doc]

I had similar done a couples of years back - new panel, new earth circuit, and the system sounds superb with no interference. Luckily I’m about 100m from the substation and my voltage is a constant 241v

 

[Mr Pig]

What you could do is get your spark to run a dedicated spur for your Hifi. If you are sure you are not going to be moving it! I'm not saying that will cure the hum, it won't, but it will sound better and cost virtually nothing if the whole house is getting rewired anyway.

 

[Mike Reed]

Hopefully they'll be installing rcbo's on all circuits with an upfront (S) type, time delay, incommer rcd ?

Once upon a time it was just RCBOs, Ian ! Obv. RCBOs are nice, but is the extra expense (or it used to be) worthwhile in a domestic circuit?

What you could do is get your spark to run a dedicated spur for your Hifi.

Radials are dedicated; spurs are not (in the electrical sense, that is)_ I think the o.p. is being sensibly cautious here in getting his domestic up to scratch (new c.u. will help a great deal). Any dedicated radial circuit(s) for hifi is a sufficiently separate and complex job for another visit once thought about, how/what/why researched and decided upon. Routing is usually the bit which needs sorting first as to ease and cost/feasibility.

 

[Mr Pig]

RCBOs are nice, but is the extra expense (or it used to be) worthwhile in a domestic circuit?

They don't cost very much more. We got the consumer unit replaced not long ago, can't remember what the price difference was but it's wasn't huge. I fully expect RCBOs to be the norm soon and mandatory for new installs shorty after that.

I know that 'spur' is not the correct term but that's what everyone calls them so... ;0)

 

[Sue Pertwee-Tyr]

My sense is that a dedicated line for the hifi ought to be wired as another ring main, as this will reduce the mains impedance and improve current draw capability over a spur or radial. Am I mistaken?

 

[Mr Pig]

My sense is that a dedicated line for the hifi ought to be wired as another ring main, as this will reduce the mains impedance and improve current draw capability over a spur or radial. Am I mistaken?

A Hi-Fi system does not draw a lot of current. Audiophiles just like to think it does.

 

[Sue Pertwee-Tyr]

I Hi-Fi system does not draw a lot of current. Audiophiles just like to think it does.

I know it doesn't, but the mains impedance thing might be relevant, mightn't it?

 

[gavreid]

I think most circuits are probably installed as radials these days. Kitchens are one place where rings might be preferred.

I had a full rcbo board installed last summer with surge protection at the cu (I think it's a 14 way without looking). I paid about £1k for the work and materials including full house test certificate for the building inspector - we were getting a loft extension anyway. The mini rcbos these days are quite cheap.

 

[chartz]

My main hi-fi is on a separate line, just because I wanted more sockets and the new room had none! I did it myself 25 years ago, I was an electrician in another life. I use one and only earth pole of about 3 metres.

 

[Mr Pig]

I know it doesn't, but the mains impedance thing might be relevant, mightn't it?

I don't know to be honest. It's not something I've heard mentioned before.

I think most circuits are probably installed as radials these days. Kitchens are one place where rings might be preferred.

This is news to me too. The domestic mains circuits I've seen have all been rings. I didn't know that had changed?

 

[Tony L]

I’ve edited the thread title in the hope of making it clearer.