Model Boat Mayhem

Mess Deck: General Section => Chit-Chat => Topic started by: Norseman on December 07, 2012, 01:53:40 am

Title: Static or Electric?
Post by: Norseman on December 07, 2012, 01:53:40 am
Hi guys
What do you think? Is my problem static or not. Occasionally my bathroom sink tap will give you a whack  :o

Ok I put a bond under there between the hot and cold pipe thinking that would cure it - nope it happened again yesterday. I also have a wire between pipes as near to the water main supply as possible - maybe 500mm. The boiler has an earth that runs to the electric meter and the gas pipe is earthed. The only other electrical device is a washing machine.

The only thing I do know is wrong is that the short earth wire inside the meter cupboard should be thicker - the boiler guy told me that.

I find it hard to believe it is mains electric because the event is so occasional and cannot be repeated. However it is a fair belt (I have had it only once) that is more than the static shock you might get in a shop.

Anyway I thought someone might have an idea what is happening.

Dave
Title: Re: Static or Electric?
Post by: DickyD on December 07, 2012, 05:54:19 am
If you are really worried Dave you need to get a qualified electrician to check out you house wiring.


Faults can be incredibly hard to find.
Title: Re: Static or Electric?
Post by: Neil on December 07, 2012, 08:43:10 am
aye........don't mess with electricity Dave...........no matter how simple you think it might be...............no life is worth 30 quid or so for want of a call out.
neil.
Title: Re: Static or Electric?
Post by: grasshopper on December 07, 2012, 09:02:34 am
If you have proper earthing to your plumbing, it sounds to me that when you walk into the bathroom and touch the cold tap you are actually discharging yourself to earth rather than the tap giving you the shock.


Are you wearing a lot of man made fibres or had new slippers, carpet etc? My wife is susceptible to static issues but won't wear the chain I want to attach to her backside! She's always getting jolts and shock around the house, wear I never seem to have an issue.
Title: Re: Static or Electric?
Post by: roycv on December 07, 2012, 09:33:56 am
Hi, have you got a meter?  If so see if you can measure AC mains from tap to where ever you touch to get a shock.
There is a difference in a static shock, perhaps you occasionally get a shock when entering / leaving your car.  If you get an AC shock it does not go away.

If you have had any new plumbing there are plastic pipes now, although I have not had a shock via that route.
40 years ago I had a house where we got shocks now and again, I resolved it to all of the pipes etc went to a common point but it had not been connected to incoming metal pipe work to obtain a good electrical earth.

This is most unlikely now but faults do occur. broken wires, corroded connections etc.
Best advice as above is to get a qualified electrician to have a look.

When I was working I had involvement in find out why workers were getting static shocks and what caused it.
There are sprays that dissipate electrical charge building up but this is unlikely to be present in a house.
regards Roy
Title: Re: Static or Electric?
Post by: grendel on December 07, 2012, 10:00:49 am
is the electricity bonded to a water pipe or gas pipe at the mains?, this used to be common, but now should not happen, a lot of earths can be bonded to the water pipes, and you can get differences in the 'earth potential' many substation sites are rated as hot earth, ie voltages on the earth side of things can vary enough to give you a shock.
best bet is to check if its static shock first, carpets, slippers etc can all cause this, then if that is ruled out time  to get your electrics checked.
Grendel
Title: Re: Static or Electric?
Post by: malcolmfrary on December 07, 2012, 11:06:22 am
If its "just" a single snap jolt, it is likely your static discharging itself into the grounded metal. 
If you are getting a shock from the grounded metal. it means that something horrible is wrong with the bonding to earth - rather than redirecting stray potential to ground, it is being redirected just where it shouldn't be.  On the plus side, I reckon that if such was the case, you would not be in a position to tell us about it.
The odd thing is, if you are generating your own static the safety wiring will make matters worse by presenting you with a discharge path just where it isn't wanted.  Try an anti static fabric conditioner in the wash.  Its not just man made fibre - years ago we were issued some rather nice pullovers in pure new wool, at about the same time we got to play with a static meter.  Trying this on the new pullover easily had it light up like a christmas tree with a reading of 12Kv plus.
Title: Re: Static or Electric?
Post by: Circlip on December 07, 2012, 11:18:09 am
"Water pipes and Gas pipes should be bonded back to the electrical earth at the meter"
 
  Yea, right. Not only are most of the pipes used in domestic systems made from plastic but the feeds from the service providers have been changed to plastic too.
 
  Regards  Ian.
Title: Re: Static or Electric?
Post by: Norseman on December 07, 2012, 12:23:46 pm
Hi Guys

Hmm, attaching a chain to the wife's backside - would it have to be proportionately large? And how would I know when she was going to get off it to enable fitting the chain? - only joking there; she does stand up.  {-)

I have this fear of getting an electrician in who turns out to be some oik off a six week dole training scheme. Maybe the local electrical factors would recommend someone.

Dropping back on previous points
Clothing - thinking about it I recall it seems to have been when they get up. My wife and daughter wear more for bed than you would think necessary for Everest. So maybe the earth route and static is the answer. I can't recall what I had been doing nor my son (but it is a fair bet he had been in bed). Only happened on six or seven occasions in all.

Actually I have just had an idea ..... But I'll digress for a second here. The Blues Brothers is on the telly and the Nun has just been madly beating them around the room with a cane - ah Sister Veronica at St Anne's Junior school, I remember her well.

Anyway - I have just realised from the mention of plastic pipes that I could insert two plastic 15mm straight connectors in the copper runs. Now would that sort it?

Dave
Title: Re: Static or Electric?
Post by: derekwarner on December 07, 2012, 12:41:57 pm
Simple test really  :D
1. stand with a pair of polyethelened lined boots & touch the tap >>:-( = above potential = just like a bird sitting on a 33Kv power line without any ill effects
2. stand with your feet in a bucket of cold tap water & then touch the tap  {-) {-) {-) {-) {-) {-) {-) {-) = below potential = you are now the earth link
...you may feel the difference.............I would call a licenced electrician............... O0 .................Derek
Title: Re: Static or Electric?
Post by: RAAArtyGunner on December 07, 2012, 09:37:23 pm
"Water pipes and Gas pipes should be bonded back to the electrical earth at the meter"
 
Yea, right. Not only are most of the pipes used in domestic systems made from plastic but the feeds from the service providers have been changed to plastic too.
 
  Regards  Ian.

Not to mention when old piping is replaced with plastic.
Which is why in Australia, Queensland at least, switchboards are now earthed via an "earth stake" and not via water pipes.
Title: Re: Static or Electric?
Post by: Howard Q on December 08, 2012, 12:03:45 am
A number of years ago I had  Renault car and what ever the seat/carpet covers were made from I could build up a quantity of static within myself, on getting out as I put the key to the lock on the door a spark would jump between them, also one day my grandson touched me and the static discharged through him, I have never seen him move so quick.
So I would recommend looking at your carpets and clothing, but more important have someone check your earthing system in the house. Howard Q.
Title: Re: Static or Electric?
Post by: derekwarner on December 08, 2012, 12:30:33 am
 >>:-( Howard...in 1972, I purchased a new Renault 12 sedan.....I thought it was a super vehicle [well compared to the 4 cylinder Holden Toranas marketed in OZ at the same time] ....but very soon after continually getting ZAPED .... a mate who also owned a R12 suggested I fit a rubber earthing strap to the back bumper bar that trailed on the road surface
Problem eliminated for a few years  :-)) & then ZAP again...... discovered the strap had worn away & was not making contact with the road >>:-(
To this day I do not understand the difference between a rubber strip contacting the vehicle chasis & the road....and the four rubber tyres contacting the vehicle chasis & the road  %%  ....Derek
Title: Re: Static or Electric?
Post by: Howard Q on December 08, 2012, 12:51:23 am
Hello Derek.
The interior make up of Renault cars must have been similar worldwide, the model I had was a Renualt 11, brilliant car, bullet proof, but!!!! moving onto a More up to date model the Laguna, it was so abissmal I didn't keep it long enough to have static problems.
Howard.
Title: Re: Static or Electric?
Post by: RAAArtyGunner on December 08, 2012, 01:38:03 am
Derek,
 
Have had a similar experience with Holdens.
 
When I looked into it further, the strap actually had strands of "wire" embedded therein.
 
Which reminds me, need to put one on current car, as am starting to get zapped on low humid days as I forget to touch the body before alighting.
 
Title: Re: Static or Electric?
Post by: grendel on December 08, 2012, 09:25:50 am
a length of toilet chain will do much the same job as that rubber strap.
Grendel
Title: Re: Static or Electric?
Post by: malcolmfrary on December 08, 2012, 10:52:43 am
Quote
Clothing - thinking about it I recall it seems to have been when they get up. My wife and daughter wear more for bed than you would think necessary for Everest. So maybe the earth route and static is the answer. I can't recall what I had been doing nor my son (but it is a fair bet he had been in bed). Only happened on six or seven occasions in all.
A different brand of fabric conditioner might do the job.  Maybe change the tap tops to plastic ones. 
If a second grasp of the tap doesn't give a shock, it is most likely personal static being discharged and proving that the earth bonding is good. 
Title: Re: Static or Electric?
Post by: grendel on December 08, 2012, 11:12:48 am
I had a work colleague who had static so bad he went round with a needle taped to his finger so he could use that to ground out before he touched things, maybe one of those static wrist bands people who work on computers use would help.
Grendel
Title: Re: Static or Electric?
Post by: Tug-Kenny RIP on December 08, 2012, 11:19:47 am
Hi Dave,

Having read through all the comments it is apparent that your water system is well earthed.   It's You that's all charged up.  I would imagine the earths are doing their thing.

Have you tried touching other earthed features within the house, like the downstairs taps. ??  or copper pipes to the radiators ,  if you have any exposed.        :}

cheers

Ken

Title: Re: Static or Electric?
Post by: sweeper on December 08, 2012, 12:48:46 pm
Yup, you've  got yourself a static problem. You can research the causes under "triboelectric values". Briefly each material has a value to produce a charge.
It can be a headache to sort out, look at what you are wearing or standing on along with the atmospheric conditions. Any  two materials rubbing together will generate the charge eg two layers of clothes or shoes moving across a surface. Hot and humid air makes the problem worse (bathroom?). From bitter experience, clean freshly washed clothes make the problem worse - a seat belt worn over a nice clean rally jacket created the worse conditions I have ever found (it blew my car radio circuit board out and gave me a real belting).
Two examples for you, the Chairman of the Electricity Board I worked for regularly got hit every time he touched his desk lamp. First thought was faulty lamp, turned out to be a new carpet fitted (wool with nylon mix). He used to pace around his office while thinking, result was a high statice charge on him. One of the large stores in the town started getting complaints from customers. Each time someone touched the door handle they received a shock, again the carpet was to blame - a few hundred people per hour moving across the carpeted entrance generated a nice charge. I have also heard of problems in a hospital laundry where the girls using the machines would get blown away by the charge. That turned out to be their underwear (manmade fibre) rubbing against their overalls in a hot moist atmosphere. Now that took some sorting out!.
Hope that helps.
Regards,
Title: Re: Static or Electric?
Post by: Howard Q on December 08, 2012, 02:17:43 pm
Hello All.
I worked for many years aircraft refuelling, one of the most important items we had on board the bowser was the static line, (tested and logged a minimum once a week for continuity), this had to be clipped into place before connecting the hose or anything else, it was the last item removed before completing job.
We also had to wear pure wool sweaters and overalls to the companies spec (anti static), we handled both grades kero and avgas so great care was needed, touching a bare metal part around the avgas fuelling orrifice with the nozzle before commencing fuelling.
Aircraft also have small discharge leads on the undercarridge which touch the ground before the wheels on landing so as to help dissipitate any static built up during flight.
Howard Q
Title: Re: Static or Electric?
Post by: Norseman on December 08, 2012, 05:57:51 pm
Yes I am now quite convinced it is static.

Anyone care to consider this - if I cut the copper pipes and insert plastic 15mm straight joints (just for the bathroom sink) will that prevent a static discharge? Or will the water in the pipes still ground out?

The few times it has occurred it does seem to have happened to sleepyheads getting up and about to brush their teeth. It can never be repeated or predicted either.

This static problem aside; at some point I need to have my electrics checked anyway as I need a modern consumer unit fitting.

Regards Dave
Title: Re: Static or Electric?
Post by: grendel on December 08, 2012, 07:42:26 pm
do they wear slippers? try suggesting bare feet (if nothing else more chance for the static to bleed off via the feet and floor).
Grendel
Title: Re: Static or Electric?
Post by: Tug-Kenny RIP on December 08, 2012, 08:08:15 pm

Quote
Anyone care to consider this - if I cut the copper pipes and insert plastic 15mm straight joints (just for the bathroom sink) will that prevent a static discharge? Or will the water in the pipes still ground out?

And then jump into the bath full of water.      %%    I'd go with Grendal's idea.

ken

Title: Re: Static or Electric?
Post by: Yarpie on December 08, 2012, 08:18:36 pm
Try getting your blood pressure and anxiety levels checked. %)
 
Seriously, I discovered that a combination of those, coupled with nylon clothing rubbing on Bedford cloth (car seats) would give me a belt, especially when leaving the car.
 
Recently, door knobs are the shockers. :o
 
Nowadays, when I approach any potential static drain, instead of grasping it fingers first (ouch!), I tend to touch it with the back of my hand first. It seems (to me anyway) that touching the conductive object with the back of the hands actually dissipates the shock somewhat (larger surface area) whereas touching with finger tip actually concentrates the zap.
 
I am the greatest respecter of electricity since Thomas Alva Edison teamed up with Michael Faraday to produce the I-phone. O0 :D
 
Yarpie.
Title: Re: Static or Electric?
Post by: malcolmfrary on December 09, 2012, 10:04:53 am
Quote
Nowadays, when I approach any potential static drain, instead of grasping it fingers first (ouch!), I tend to touch it with the back of my hand first. It seems (to me anyway) that touching the conductive object with the back of the hands actually dissipates the shock somewhat (larger surface area) whereas touching with finger tip actually concentrates the zap.
When you get a static shock as a result of a normally repeated action, like grasping a door handle or tap or similar, its always the same bit of hand that passes the discharge, so you gain a little hole in the insulating layer of skin at that spot.  After a few goes, this gives a good path to the squidgy stuff underneath that conducts electricity and contains lots of nerves, and the effect is multiplied.  Going back of hand first offers the hairs on the back of your hand first, and probably results in a more gentle discharge.
Title: Re: Static or Electric?
Post by: sweeper on December 09, 2012, 12:26:01 pm
Norseman,
You've started to answer your own question. Think along the lines of duvet covers (nylon?), night clothes and human movement during the night. Result, nice build up of charge. My suggestion would be to examine anything that has changed since before you started to have the problem. You may just be able to pin down the cause from this. In my opinion (for what that's worth!) you can discount any connection between the static and your household wiring system.
Having being involved in this subject in industry I know that the causes and cures (or limitation) for static is a very weird topic to get into. It may be of some comfort to you that each human reacts in a different way to electrical charges. Some people are very prone to feeling the smallest charge while others feel very little. Sadly, I am one of the first group (not ideal for someone working in  the industry), the slightest charge can do me a serious mischief. The only consolation that you have is that it is a nuisance rather than danger factor in domestic situations.
Sorry not to be able to pin it down to a definiate cause.
Regards.