Earth Rod Box

[Stevoon]

Hi,

I am in the process of retrofitting an enclosure for my TT Earth Rod. Should the incomming Earth wire be in conduit where it runs down the outside of the house and then through the soil to the Earth Rod? Also how deep should the Earth wire be burried? At the moment I'd say it's lucky if its more than 2" down.

Thanks

 

[ericmark]

Not an easy question as the answer is all about gradient and time.

Where a 30ma 40ms RCD is used then any current going to the earth rod will be for a very short time so there is no real problem.

However where a current under fault conditions could run for some time then while this current is running there will be a gradient in the ground and any animal touching the ground at two different points could get a shock. With quadrupeds current between the front legs is a real problem as even a low voltage of 25 volt can kill a cow.

In the main we do a risk assessment and also cover the rod with a special pit or even a concrete slab so the surface directly above the rod is either non conducting or its self earthed.

The sizes of earth wire are laid down so unlikely to be physically damaged this changes if in conduit or under ground and in the main electricians tend to use some common sense rather than try to measure gradients etc.

So if you can see the wire then at least 4mm sq this can rise to 25mm sq according to the protection.

 

[Stevoon]

Thanks Eric.

I have the earth rod already installed (when I moved into the property.) From a look at the cable it's 16mm, run down the outside of the wall in 25mm Black conduit which stops approx 18" from the ground. From here the cable continues underground (buried 2" deep) for about 2' to the Earth rod itself. I'm buying the Earth Rod enclosure from Screwfix (http://www.screwfix.com/p/plastic-inspection-earth-pit/16092).
The Consumer unit is protected by a 30ma RCD.

Thanks

Stephen

 

[JohnW2]

I have the earth rod already installed (when I moved into the property.) From a look at the cable it's 16mm, run down the outside of the wall in 25mm Black conduit which stops approx 18" from the ground. From here the cable continues underground (buried 2" deep) for about 2' to the Earth rod itself.

A buried 16mm² earthing conductor without any mechanical protection (e.g. conduit) is acceptable in terms of the regs, but whether it is sensible/wise to have it so close to the surface that it is likely to be susceptible to mechanical damage is a different matter. If the shallow burying is unavoidable, I would personally be seriously consdiering some mechanical protection, since I know what happens when I get my spade out!

Kind Regards, John

 

[Stevoon]

Thanks, I just didn't like the look of it so close to the surface. I shall get some conduit to match that already installed and run it in this to the new enclosure.

On digging round the top of the rod it appears there has been an attempt at an enclosure in the past, the rod has been installed through a 3" plastic plantpot!

 

[JohnW2]

Thanks, I just didn't like the look of it so close to the surface. I shall get some conduit to match that already installed and run it in this to the new enclosure. On digging round the top of the rod it appears there has been an attempt at an enclosure in the past, the rod has been installed through a 3" plastic plantpot!

Yes, one sees all sorts of things like that. There's actually no requirement for any sort of enclosure, and most domestic earth rods probably don't have anything at all.

Kind Regards, John

 

[Stevoon]

I'm only fitting one as it was picked up on my PIR when I bought the property that one was missing. Just thought it best to as it's down the side of my Bungalow where people sometimes walk.

 

[JohnW2]

I'm only fitting one as it was picked up on my PIR when I bought the property that one was missing. Just thought it best to as it's down the side of my Bungalow where people sometimes walk.

It would be interesting to know what, if any, regulation was cited about this in the PIR. I'm not convinced that those boxes afford much protection - but they do serve a useful purpose in being fairly conspicuous and therefore reducing the chances of people treading on the rod or attacking it with a tool!

Kind Regards, John

 

[Stevoon]

I've just checked the report I got, all it says is "9. No box to earth stake. C2" Nothing on the report cites any regulations, just what the defect is.

Thanks

Stephen

 

[sparkiemike]

It would be interesting to know what, if any, regulation was cited about this in the PIR. I'm not convinced that those boxes afford much protection - but they do serve a useful purpose in being fairly conspicuous and therefore reducing the chances of people treading on the rod or attacking it with a tool!

Kind Regards, John

How about 542.3.2, last sentence

 

[JohnW2]

How about 542.3.2, last sentence

I really don't think that one of those plastic boxes offers significant protection against corrosion, do you? Come to think about it, I'm not sure that I've ever seen a domestic earth rod whose connections were meaningfully 'protected against corrosion', so maybe they are all non-compliant!

Kind Regards, John

 

[RF Lighting]

Wrap it in denso tape if you want to protect against corrosion.

 

[JohnW2]

Wrap it in denso tape if you want to protect against corrosion.

That certainly sounds more likely to afford some protection against corrosion than a plastic box.

Kind Regards, John

 

[Stevoon]

Sorry to resurrect an old post, but would this be a suitable box http://www.ebay.co.uk/itm/EARTH-ROD...ls_Supplies_Electrical_ET&hash=item3f1d06e45d

Thanks

Stephen

 

[ban-all-sheds]

Wrap it in denso tape if you want to protect against corrosion.

Wrap the entire rod in it for maximum protection.










Advice provided for entertainment purposes only. This advice does not reflect the thoughts or opinions of either DIYnot.com, its friends, or its letterhead; don't quote the site on that; don't quote the site on anything. This site may contain nuts. All rights reserved; you may distribute this URL freely but you may not make a profit from it; terms are subject to change without notice; illustrations are slightly enlarged to show detail; any resemblance to actual persons, living or dead, is unintentional and purely coincidental; do not remove this disclaimer under penalty of law; hand wash only, tumble dry on low heat; do not bend, fold, mutilate, or spindle; your mileage may vary; no substitutions allowed; for a limited time only; this website is void where prohibited, taxed, or otherwise restricted; caveat emptor; website is provided "as is" without any warranties; reader assumes full responsibility; an equal opportunity website; no shoes, no shirt, no service; quantities are limited while supplies last; if any defects are discovered, do not attempt to read them yourself, but return to an authorized service center; read at your own risk; parental discretion advised, text may contain explicit materials some readers may find objectionable; keep away from sunlight; keep away from OJ; keep away from pets and small children; limit one-per-family please; no money down; no purchase necessary; you need not be present to win; some assembly required; batteries not included; instructions are included; action figures sold separately; no preservatives added; slippery when wet; safety goggles may be required during use; sealed for your protection, do not read if safety seal is broken; call before you dig; not liable for damages arising from use or misuse; for external use only; if rash, irritation, redness, or swelling develops, discontinue reading; read only with proper ventilation; avoid extreme temperatures and store in a cool dry place; keep away from open flames; avoid contact with eyes and skin and avoid inhaling fumes; do not puncture, incinerate, or store above 120 degrees Fahrenheit; do not place near a flammable or magnetic source; smoking this website could be hazardous to your health; the best safeguard, second only to abstinence, is the use of a condom; no salt, MSG, artificial colour or flavouring added; if ingested, do not induce vomiting, if symptoms persist, consult a physician; website is ribbed for your pleasure; possible penalties for early withdrawal; offer valid only at participating sites; allow four to six weeks for delivery; must be 18 to read; disclaimer does not cover misuse, accident, lightning, flood, tornado, tsunami, volcanic eruption, earthquake, hurricanes, ball lightning, and other Acts of God, neglect, damage from improper reading, incorrect line voltage, improper or unauthorized reading, broken antenna or marred cabinet, missing or altered serial numbers, electromagnetic radiation from nuclear blasts, sonic boom vibrations, customer adjustments that are not covered in this list, and incidents owing to an airplane crash, ship sinking or taking on water, motor vehicle crashing, dropping the item, falling rocks, leaky roof, broken glass, mud slides, forest fire, or projectile (which can include, but not be limited to, arrows, bullets, shot, BB's, shrapnel, lasers, napalm, torpedoes, or emissions of X-rays, Alpha, Beta and Gamma rays, knives, stones, etc.); other restrictions may apply. This website is meant for educational purposes only. Any resemblance to real persons, living or dead is purely coincidental. Void where prohibited by law or common sense. Some assembly required. List each check separately by bank number. Batteries not included. Contents may settle during shipment. Use only as directed. No other warranty expressed or implied. Do not use while operating a motor vehicle or heavy equipment. Postage will be paid by addressee. Subject to approval. This is not an offer to sell securities. Apply only to affected area. May be too intense for some viewers. Do not stamp. Use other side for additional listings. For recreational use only. Do not disturb. All models over 18 years of age. If condition persists, consult your physician. No user-serviceable parts inside. Freshest if eaten before date on carton. Subject to change without notice. Times approximate. Simulated picture. Breaking seal constitutes acceptance of agreement. For off-road use only. As seen on TV. One size fits all. Many suitcases look alike. Contains a substantial amount of non-tobacco ingredients. Colours may, in time, fade. Simulated words. We have sent the forms which seem to be right for you. Slippery when wet. For office use only. Not affiliated with the International Red Cross. Drop in any mailbox. Edited for television. Keep cool; process promptly. Post office will not deliver without postage. List was current at time of printing. Return to sender, no forwarding order on file, unable to forward. Not responsible for direct, indirect, incidental or consequential damages resulting from any defect, error or failure to perform. At participating locations only. Not the Beatles. Penalty for private use. See label for sequence. Substantial penalty for early withdrawal. Do not write below this line. Falling rock. Lost ticket pays maximum rate. Your cancelled check is your receipt. Add toner. Place stamp here. Avoid contact with skin. Sanitized for your protection. Be sure each item is properly endorsed. Sign here without admitting guilt. Employees and their families are not eligible. Beware of dog. Contestants have been briefed on some questions before the show. Limited time offer, call now to insure prompt delivery. You must be present to win. No passes accepted for this engagement. No purchase necessary. Processed at location stamped in code at top of carton. Shading within a garment may occur. Use only in well-ventilated area. Keep away from fire or flame. Replace with same type. Approved for veterans. Booths for two or more. Check here if tax deductible. Some equipment shown is optional. Price does not include taxes. No American coins. Not recommended for children. Prerecorded for this time zone. Reproduction strictly prohibited. No solicitors. No alcohol, dogs, or horses. No anchovies unless otherwise specified. Restaurant package, not for resale. List at least two alternate dates. First pull up, then pull down. Call toll free before digging. Driver does not carry cash. Some of the trademarks mentioned in this product appear for identification purposes only. Record additional transactions on back of previous stub. Decision of judges is final. Don’t eat yellow snow.