Getting constant electric shocks

lemondrops69

Sounds shocking 

samster1

Mickey666 said:

Risteard said:

It sounds like the installation isn't Earthed. Likely there is no connection between the MET (Main Earthing Terminal) and the Earthing Conductor. You should de-energise the entire installation as a matter of urgency until this has been rectified.

Sounds more like a static problem to me.  OP says they still get shocks "even when the electricity is off" so why do you think it could be an installation problem?  Especially as OP gets a shock from door handles, which would never have any connection to the mains earthing system would it?

Patio door handles and sing, tile trim that's metal too. 

coffeehound

samster1 said:

its as if its a capacitor charging and then when I touch it it discharges through me but its constantly not just now and then. 

You are the capacitor charging up from friction with the floor, then getting a zap as you equilize charge with metal objects

Ebe_Scrooge

chrisw said:

For the past couple of weeks I've been getting nasty shocks getting out the car and even putting the key in the house front door lock. Nothings different in terms of clothing,etc.

Top tip for the car thing.  Open the car door, then make sure you've got your hand on the door frame (or the pillar, or the roof, wherever is convenient, as long as it's metal) before you put your foot on the ground.

I'm sure someone will be able to explain the physics of it, but it usually does the trick :-)
I get some real belters occasionally - I'm guessing it's a combination of my shoes having spent ages rubbing against a nylon mat, as well as my trousers against a fabric seat, builds up a pretty hefty static charge.

samster1

Stood in my socks and the shocks have stopped. It's defo a static problem from the laminate flooring. Strangely once I put shoes on the shocks are pretty much still gone. I wonder if by cleaning the flooring it's helped make an earth connection. I actually have a hnc in electrical engineering and understand the earthing systems I just had never thought in a million years that laminate could cause this to happen. 

fenwick458

how odd. So can you please explain what you have had done that made this happen?

I can't really offer any solutions in explanations I'm just interested.

I once noticed years ago that if I picked up my iPhone 6 whilst it was on charge from the double socket with USB outlets(or a 13A plug in fast charge outlet >2A) that when I stroked the outer metal casing I got a weird and noticeable vibration feeling though my hands. that was barefoot and on a tiled floor. If I did it in socks, or just plugged into a regular apple 13A USB outlet,  nothing happened. I'm still not entirely sure what or how that happened to this day

coffeehound

Thinking about this, it might be a bit different from the usual one where scuffing your shoes on carpet charges you up.  

As J_C identified, the floor has an insulating underlay which is earthed underneath but free to build up a charge on top.  (Actually as it charges on top, it will attract opposite charge underneath from ground, effectively doubling the tension.)  Normally this would bleed off naturally through humidity, but with low indoor humidity, it has charged up more.  The laminate itself will be a bit conductive/permeable and allow charge to pass through.  

When you walk on it, you distort the high electric field causing a charge concentration as you get near uncharged or earthed objects which makes the jump given the opportunity.  As there is a bigger reservoir of charge, it happens more often/longer than with nylon underpants/car seat type scenarios.  Yes, mopping the floor will have increased local humidity allowing charge to bleed off.

Jeepers_Creepers

Now't as weird as electrickery.

I think what happens with 'static' electricity, is that it needs two materials, almost certainly of different types, and when they made contact with friction, electrons pass - are 'rubbed' - from one to the other; one gains (becomes 'charged'), and the other loses electrons.

These materials also need to be insulators in their own right, or else the electrons would immediately flow/jump back to the giver - no charge would build up.

When Sam wears shoes, they'll have insulated soles but which also happen to be one of the types of material - presumably 'dielectrically' different - to that of the laminate flooring. He becomes 'charged' relative to the floor (or perhaps it's the floor which becomes charged, I guess), and this imbalance is always looking for a way back. As soon as Sam touches anything that's at a different potential to his charged self, and provided it is a conductor to some degree, it's ouch time. When he is barefoot or wearing socks, his feet are no longer good insulators, so the electrons immediately flow right back - or are not rubbed off in the first place

A lot of it doesn't make sense - I mean, does the handle then discharge down through the door to the floor? - but it happens, so there is an explanation!

With capacitance - amazing stuff - the 2 sides don't even have to be connected to each other for one side to build up electrons and the other lose them, they only have to be close. So possibly Sam is discharging himself to the tiles and handles via capacitance rather than returning the electrons directly to the floor. So I guess he could have 'charged' the handle or tiles, but that will probably quickly dissipate via the door and walls.

(If you have a DC source with a wire from each end, and you simply bring these two wires close together, electrons build up on one wire and are lost from the other due to capacitance effect.)

My son has been complaining about similar to you, Fen - when his wrists touch against his metal-bodied laptop, he receives an unpleasant tingle. This isn't 'static' because it's continuous and only happens when the mains adaptor is plugged in. He was also complaining of similar things happening with his Samsung phone charger and his metal-bodied Samsung phone. On the surface, this doesn't make much sense as the laptop runs at 20V and the phone at 5V, neither of which should be detectable through your skin - the 20V, perhaps, if the skin were damp. However, just because it's a PD of 20V between the two pins of the DC plug, doesn't mean it's also 20V between either of these pins and the ground = you.

Voltage should always be thought of as 'potential difference' between two points, and not as a single 'voltage' at one point. For instance, if you touched a 240V mains wire, you would have a PD of 240V across you between that wire and the ground = painful, possibly deadly. If, however, you wired up a metal plate to the live mains and then stood on it, you'd be fine (not that I'm suggesting you try this - for a start, you'd be fried when one foot was on and one off...). Even a plate wired to a 10,000V overhead HT cable - no problem. But if someone lowered a wire to you from that same source which was at 10,240V, then you'd receive your 240V - enjoy.

Back to the phone or laptop; these are sending the regulated 5V DC or whatevs voltage to the device via two wires, with 5V between them. The device therefore receives its 5V because it's only connected to these two wires, one of which it considers to be 0V and the other is +5V - ie 5 volts above the other one; 5 volts between them, 5 volts potential difference. But as far as we are concerned, standing as we are on the ground (the 'ground' is what we consider to be 0V) that DC plug could be at anything! It could be that one wire is at 20V and the other at 25V. That gives the phone its 5V, but it would give us 20 or 25V, depending on which one we touched (these are mains-powered adaptors, so ultimately have a path back to 'our' ground zero, even if it's via the Neutral wire - which is also effectively 'earth').

So, somehow, I suspect my son and Fen are getting 20V or more - whatever the sensitive bits of skin can detect - from the wire the phone considers is 0V!

Something like that is going on... :-)

Grizzlebeard

Static shock is in the order of a thousand to a million volts. Unlike lighting, the energy stored and discharged is minuscule, measured in hundredths of a joule. Only micro amps or nano amps of current flow, so you feel it, but it doesn't burn or kill you. For comparison, the spark of a piezo electric spark in a cigarette lighter is probably more powerful in terms of energy and only at a few thousand volts.

Static builds up and is retained on a brand new laminate floor because the surface is pristine and uncontaminated so the charge can't leak away. But one only needs to wash the floor with tap water once or twice before a molecule or two thickness of contamination forms and is enough to conduct the charge away.

I think that's enough to explain what's going on.

(The figures I suggest are only ball-park guesstimates and not scientifically definitive, so please don't quote them as facts.)

Grizzlebeard

Jeepers_Creepers said:

Now't as weird as electrickery.

,,,,, Fen - when his wrists touch against his metal-bodied laptop, he receives an unpleasant tingle. This isn't 'static' because it's continuous and only happens when the mains adaptor is plugged in......

The plugged in laptop tingle is micro amps of current from the 250vAC mains leaking through the Power supplies Y2 suppressor capacitors (~ 1500pF) to the devices common circuitry. The device itself is considered double-insulated so is not connected directly to the mains earth wire. An alternating AC voltage of up to 400V peak may appear on all external parts on the laptop, but because of the low value of the suppressor capacitors only micro amps can flow: Some tingle but no smoke! This phenomenon can occur in any modern electronics that has no mains earth connection. i.e. only two wires in the plug.

Ironically laptop PSUs have mains earth wires - to kill interference - but this isn't connected to the secondary 20-ish V output which is floating. This stops any risk of damaging currents flowing when connected to other external stuff through USB or LAN ports or telephone lines etc.

So the continuous laptop tingle is leakage as you suggest rather than static,