Pme

[stew0001]

Ok, I have a basic understanding of electrical issues, but what I don’t figure is the PME system.

The earth is connected to the neutral in the meter box, now if we touch the earth wire its ok, yet touching the neutral is a bad idea…zapp.

so with the earth connected to neutral (and copper pipes around the house)why dont we get a zap?

 

[ChrisElectrical88]

You shouldn't be getting a belt off the neutral if it's wired and isolated correctly.

 

[bigspark17]

I do hope your not a spark?? Appologies if not,, if you are thinking of doing diy on your electrics dont,! This is fundamental stuff!!

 

[Simonslimline]

Neutral and Earth are at the same potential.

 

[ChrisElectrical88]

If you are a DIYer please for your own sake make your own PME at your house!

 

[HandySparks]

If you are a DIYer please for your own sake make your own PME at your house!

Do you really mean this?

 

[Marvo]

Okay I assume it was a typing error above but just for clarity NEVER PME AN INSTALLATION unless you get specific permission from the DNO.

 

[Guitarist]

Okay I assume it was a typing error above but just for clarity NEVER PME AN INSTALLATION unless you get specific permission from the DNO.

And even then, it's your supplier who must make the connection.

 

[stew0001]

thanks for the replys guys, nope im not doing any DIY stuff, i was just wondering why touching the neutral would give a shock while touching the earth does not, even though they are connected at the meter box.

hmmmm... so if they are connected, when replacing a plug to an appliance whatever, miss connectiong the neutral and earth everything would still work? (no, i havent ever done that)

 

[telectrix]

if you reversed the Nand E then the appliance would generally work unless there was a RCD in the circuit. this would immediately trip when you switched the appliance on.

 

[stew0001]

ok, thanks for the the info guys,
when did they do away with having the earth going to a spike in the ground?

 

[Engineer54]

ok, thanks for the the info guys,
when did they do away with having the earth going to a spike in the ground?

They haven't done away with earth rod earthing (TT system). But what would you rather have protecting your installation, a Ze of < 0.35 ohms or an Ra of potentially 200 ohms?? No contest, PME every time!! lol!!

 

[HandySparks]

... i was just wondering why touching the neutral would give a shock while touching the earth does not, even though they are connected at the meter box.

Unless there's a fault, it won't.

 

[stew0001]

good point, the <0.35 ohm sounds a LOT safer