frankv:

 

230V wires are coloured whereas 110V are colored ;)

 

 

 

🤣

richms:

American stuff is blatantly unsafe how they do things, Single insulation, wirenuts inside a metal base, no earthing and wires in screw terminals is a disaster in the making. So many cringe videos of "derp look at me Im a woodworker and I made a lamp" on youtube.

neb:  The US has mains wiring standards that are illegal in almost every other country because of how unsafe they are. Do not follow any US instructions or guides on doing mains wiring.

I'd never follow them just because I assumed they'd be different to ours but dang, I didn't realise they were also just sh*t in their own right!

Rikkitic: 240 volts will kill you many times over if you get it wrong.

Just to be a little pedantic here: voltage is not the issue, it's current (Amperage) that kills. Anything over 100mA can (but not necessarily will) kill you. 

Dratsab:

 

Rikkitic: 240 volts will kill you many times over if you get it wrong.

 

Just to be a little pedantic here: voltage is not the issue, it's current (Amperage) that kills. Anything over 100mA can (but not necessarily will) kill you. 

 

I am well aware of that but it takes a sufficiently high voltage to overcome the resistance of your body to push that much current through your heart. Ohm's law again. I'm not sure exactly how much voltage is deadly. It depends on how wet you are, amongst other things, but I would guess around 50 or 60 volts will do it in some circumstances. 

neb:

richms:

 

American stuff is blatantly unsafe how they do things, Single insulation, wirenuts inside a metal base, no earthing and wires in screw terminals is a disaster in the making. So many cringe videos of "derp look at me Im a woodworker and I made a lamp" on youtube.

 

Quoted the above to emphasise how important this is: The US has mains wiring standards that are illegal in almost every other country because of how unsafe they are. Do not follow any US instructions or guides on doing mains wiring.

I would be interested to know if there are any statistics on electrocution and electrical house fires in America. What is less safe in principle is not necessarily less safe in practice. There is a lot of panic about this kind of thing. The lower mains voltage there can also make a difference.

Stu: Many places in the USA actually have dual voltage. Not just the lower 110/120V, but also 220/240V is found in many homes. Higher voltage for larger appliances, lower voltage for lamps, and other smaller plug in appliances etc.

Its split phase, so basically as "safe" as 120v because there is only 120v to earth.

They do everything weird over there with arbitary voltages in the street and then one transformer per house or few houses to take it down to the 120/240v level and may not have 3 phases in an entire suburb which is why all the US workshop channels make a big deal about having 3 phase power for their big machines.

Commercial places will get higher voltages but not _that_ high and they have to provide their own transformer for their normal loads. When a friend was ordering some gear from there there was about 10 voltage options to choose from with weird names. I thought that "high leg" was hilarious.

Dratsab:

 

Rikkitic: 240 volts will kill you many times over if you get it wrong.

 

Just to be a little pedantic here: voltage is not the issue, it's current (Amperage) that kills. Anything over 100mA can (but not necessarily will) kill you. 

 

30mA for 30ms is the guideline usually used on where it starts to get fatal iirc.

Daynger:

 

 

 

30mA for 30ms is the guideline usually used on where it starts to get fatal iirc.

 

Maybe applied directly to the heart, but that's not a very useful guideline in practice.

richms:

They do everything weird over there with arbitary voltages in the street and then one transformer per house or few houses to take it down to the 120/240v level

mattenz:

 

Daynger:

 

 

 

30mA for 30ms is the guideline usually used on where it starts to get fatal iirc.

 

 

 

 

Maybe applied directly to the heart, but that's not a very useful guideline in practice.

 

Any hand to hand, hand to foot, head to foot etc shock will travel directly through your heart, so yeah, its a pretty good guideline for practice.

Directly across the heart, as in surgury etc, will be considerably lower, hence the use of 10mA RCDs for medical equipment and 30mA for general use.

As an electrician i get reminded of this every two years with the safety and basic first aid certification we need to complete to stay licensed.

RC: Check the wire connections to the rear of the lamp holder and if all is well it can be left alone … the insulation might have hardened near the end because of years of heating by the bulb - in which case you just cut it back then reconnect.

Bung:  By this time it's long overdue for replacing that old Trurip with a proper double insulated cable.

Fully agreed! Even if the insulation at the lamp end wasn't brittle I would be replacing the cord with a double insulated one.

Bung: Exposed metal on non double insulated appliances is earthed so the fuse will blow if it becomes live. The obvious thing to do if changing a broken bulb is to unplug the lamp first.

Unplugging a broken lamp is doubly important when it is impossible to visually identify whether the lamp switch is in the on or off position - but a vital step regardless.

I am still in two minds as to whether or not I should add a ground connection to the metal lamp base or head. The cord connects to the rear of the lamp holder which is a plastic part. I can't see how a loose connection could short to the base.  I think the point about the risk of introducing a direct path to ground when changing the bulb (I can't guarantee that someone else will change out a blown bulb has a lot of merit.