How many appliances should be on one breaker?

[trader_4]

Even if you had 30A running through 18g, you only wind up with 36W over a one meter lamp cord length.

[gfretwell]

I guess those guys at NFPA who established the fixture wire standard understand these things ;-) If you noticed, the NRTLs stopped listing 18 ga extension cords too. In a commercial setting most fire marshals will tag any extension cord or plug strip that does not have a breaker in it and some will only allow a plug strip if it is for surge protection.

[clare]

They colonized Zambia.

[James Wilkinson Sword]

Why waste money having a thicker more clumsy 16A conductor when you can use a 1A one protected by the correct fuse?

[James Wilkinson Sword]

It's "maths" with an S you Yankee moron. Let me explain. P= I^2 R. The heat from 15 amps in the wire is TWO HUNDRED AND TWENTY FIVE times greater.

[James Wilkinson Sword]

I have used a 13A extension cord at 13A 24/7. It gets well over body temperature. Multiply THAT by 19 squared.

An electrode needs damp concrete to conduct. It's the water that conducts, aided by the surface area of the concrete. You need to put the concrete deep underground to make an electrode. I don't know about your weird concrete base housing, but ours has concrete round the edges, deep under the supporting walls. That foundation will probably touch the water table. So if there was a wire inside it, that wire would be earthed. But not the dry insulating parts of the concrete.

[James Wilkinson Sword]

"Normal concrete is effectively an insulator in the dry state"

[James Wilkinson Sword]

I just connected a table lamp up in my garage, then interrupted the connection and tried to use the concrete floor to conduct. Guess what? No light from the bulb!

[James Wilkinson Sword]

"Moist concrete behaves as an electrolyte with resistivity of up to 100 ohm-m. Air dried concrete has a resistivity in the order of 10 000 ohm-m, whilst oven-dry concrete has a resistivity in the order of 100 000 000 ohm-m."

So unless your house is flooded, that's 10,000 ohms, even if your touching it with a 1m^2 foot! Now I know you're a dopey Neanderthal who can't understand maths, sorry "math", but even your feet aren't that big. And 10 kohms is a big RESISTANCE.

[James Wilkinson Sword]

This is SPECIAL concrete, with stuff added to make it conduct more. It's still enough resistance to create a large heater. If you were right and it was a ground, that would short out their idea completely.

[James Wilkinson Sword]

18 ga wire is pretty thick, not very useful for a table lamp or radio. We have nice flexible wires for those, usually 24 ga. A vacuum cleaner will have 20 ga. 18 ga is for things like kettles.

[James Wilkinson Sword]

12 ga (or a ring of 15 ga).

[James Wilkinson Sword]

Our extension cords have fuses in the plugs. So you can't go and plug two big appliances in the end and melt it.

And the better quality reel extensions have a thermal breaker inside incase you try to use it at full load for ages while it's coiled up.

[James Wilkinson Sword]

We colonized a lot of places, then we became politically correct and everything went t*ts up.

[gfretwell]

... and you had to "cheap out" in the copper.

[James Wilkinson Sword]

No, we use enough copper to carry the current required. Usually half what you do, as we have a higher domestic voltage, which allows us to have floppier flexes.

[trader_4]

It's not 16g, it's 18g for lamp cord, which isn't clumsy at all. An obvious advantage to a heavier cord is that it's less likely to get damaged, be able to take typical abuse, etc.

[trader_4]

That must be some Britt thing you limey village idiot.

Let me explain. P= I^2 R. The heat from 15 amps in the wire is TWO HUNDRED AND TWENTY FIVE times greater.

Heat in one meter of 18g lamp cord at 1A is a whopping .04 watts. Heat in one meter of 18g lamp cord at 15A, is 225 times greater, it's a whopping

9 watts. Now explain to us how a fire starts from 9 watts in a meter of lamp cord wire. Apparently you failed math, because you think because something is 225 times greater, that means it must be HUUGE! Stop embarrassing yourself.

And again, if this was a real problem, a real cause of fires, it would have been addressed in the code. There are billions of these cords in operation every day.

[trader_4]

On Sunday, January 15, 2017 at 4:18:46 PM UTC-5, James Wilkinson Sword wrot e:

e:

rote:

ing it can take.

A. That's very hot.

perature. Multiply THAT by 19 squared.

elieve you guys are stupid enough to have 1 amp cord protected at 15 amps.

no information in it whatsoever.

sn't dunked below the water table like an electrode. We were discussing co ncrete slab under a house, which will not be even damp, or you'd have a ver y soggy carpet.

/wiki/Ufer_ground

one end of the rebar up out of the concrete at a convenient location to ma ke an easy connection point for the grounding electrode.[4]

g World War II. It uses a concrete-encased electrode to improve grounding i n dry areas. The technique is used in construction of concrete foundations.

storage vaults near Tucson and Flagstaff, Arizona. Conventional grounding systems did not work well in this location since the desert terrain had no water table and very little rainfall. The extremely dry soil conditions wou ld have required hundreds of feet of copper rods to be inserted into the gr ound in order to create a low enough impedance ground to protect the buildi ngs from lightning strikes.

s, aided by the surface area of the concrete. You need to put the concrete deep underground to make an electrode. I don't know about your weird conc rete base housing, but ours has concrete round the edges, deep under the su pporting walls. That foundation will probably touch the water table. So i f there was a wire inside it, that wire would be earthed. But not the dry insulating parts of the concrete.

Please test this out for us. Go stand in your bare feet on some typical con crete floors that are on grade and grab one of those 220V conductors. Even bette r, grab a higher voltage one. Report back (or not) the results.

[trader_4]

On Sunday, January 15, 2017 at 4:39:18 PM UTC-5, James Wilkinson Sword wrot e:

e:

rote:

elieve you guys are stupid enough to have 1 amp cord protected at 15 amps.

no information in it whatsoever.

sn't dunked below the water table like an electrode. We were discussing co ncrete slab under a house, which will not be even damp, or you'd have a ver y soggy carpet.

/wiki/Ufer_ground

one end of the rebar up out of the concrete at a convenient location to ma ke an easy connection point for the grounding electrode.[4]

g World War II. It uses a concrete-encased electrode to improve grounding i n dry areas. The technique is used in construction of concrete foundations.

storage vaults near Tucson and Flagstaff, Arizona. Conventional grounding systems did not work well in this location since the desert terrain had no water table and very little rainfall. The extremely dry soil conditions wou ld have required hundreds of feet of copper rods to be inserted into the gr ound in order to create a low enough impedance ground to protect the buildi ngs from lightning strikes.

es-and-potential.html

Note that your source is promoting a new product, "conductive concrete", which is enhanced to make it MORE conductive than regular concrete. The problem with the above is that is specifies "dry state", but does not define dry. I said in my very first post that concrete that is totally dried out, eg in an oven, would have low conductivity. But that isn't the concrete in a typical floor in a house, garage, industrial building, basement, etc.