Simple Electricity

Simple Electricity – Sit Class

This was originally to fall under Jokes but ended up here and some electricians can read this as well, especially those taking short cuts or those private a__holes using “Speaker wires” to cut cost in South Africa!!! (you are going to kill someone, hopefully yourself and not your child)


Let’s call the height of the dam on the hill the Voltage (the Volts will stay the same with the only possible fluctuation depending on the water level inside the dam)
The water coming from the pipe is the stream = Current = Amps
The tap is the resistor = ohms (by controlling the tap we control the flow)

Electrical energy usage are measured in watts, and watts are calculated by Volts x Amps = therefore the current we need for something to work in a circuit.

“AC:” (Found in buildings – most economical to distribute over distance)
If an appliance or piece of equipment is 3kw - 3000w we need
240V circuit = 3000 240 = 12.5Amps
110V circuit = 3000 110 = 27.27Amps
If the voltage drops the required Amps go up

The thickness of a cable or wire is determined by the Amps/current we are going to use in that circuit.
A Circuit Breaker (CB) is for the protection of the cable/wire to prevent it from overheating and fire (it is not to protect appliances or electrical plug-ins).
A bad/loose connection can result in tripping the CB and overheating normally at the point of the problem. This is due to the wattage of the equipment asking more Amps from the circuit to perform correctly.
All electrical spares and equipment does have a lifetime and quality differ in price, but you do not need a Rolls Royce while the cheapest No-name will cost you more in the end (made in ???).

The Earth Leakage:
Are for protection of life – in a AC circuit we need two wires; a Live and Neutral. If for some reason they draw different loads (unbalanced) the Earth Leakage will trip (this means the amps are leaking somewhere)
When using an Earth Leakage you can sometimes find 2 neutral bars in a Distribution Box (DB). Make sure the wires run from the correct neutral bar. The live wires from the Earth Leakage must have their matching neutrals from the Earth Leakage neutral bar only. Neutrals from elsewhere will unbalance and trip it

Fault finding – remove all the neutrals on the specific neutral bar and start putting them back one at a time. Switch on/off between every wire you put back. The one tripping it is the circuit with the problem. The quick way is by unplugging everything and see which one solve the problem - this will however not high-light every problem like the neutral bar method. If you do not have the tools – do not F_ck around

”DC:” (Vehicles - batteries)
All I can say is that if you do not have the wiring diagram and/or some knowledge you will struggle. Make a small 12V lead light.

”Sound:” (Your powerful Low-Fi system is useless if not pure – distortion is not power)
Speakers do not work with Direct Current (DC). Make sure the wattage can be handled by the amplifier output or it’s bye, bye speakers – not more or better sound. If you do not understand series and parallel connections ask someone with knowledge or burn your fingers.
As with speakers the amplifier output can blow if overloaded by the speakers – Again ask someone with knowledge

Normally an amplifier will specify the ohms and output power, and matching speakers that are of a 20% higher RMS value should work best. RMS is the constant maximum wattage a speaker can handle not the peak power advertising gimmick.

sounds like you need a bigger hammer, I use hammers for all my electric problems.

a reply to: ICycle2

That's not really how power distribution works. To use some of your words for context, some clarifications...

It is the size of the pipe which determines the current, not the 'tap'. The current is regulated by a circuit breaker which will only allow so much current through it. The circuit breaker therefore determines the diameter of the 'pipe' (both upstream from it, and downstream from it, but it's different circuit breakers).

The amount of voltage in the 'pipe' is determined by transformers, and at the consumer end it is at a dramatically lower voltage than on the distribution end of the equation. There are several transformers between your house and the distribution from a power plant.

It is not entirely true to say it is more efficient to distribute AC power than it is DC. Power 'distribution' at low voltages is an inefficient process with both DC and AC. However, recent studies show that distribution of very, very, high voltage DC is actually more efficient than AC distribution at the same voltages. In fact, there are even some major power distribution segments in the USA which distribute DC, not AC, for this reason. One of them is in Utah. These are relatively new though. And, there are several downsides to working with DC voltages this high. DC is twice (or more) as deadly as AC when something goes wrong.

Regarding audio, yes, the signal applied to your speakers is an AC waveform. However, it's not really correct to say an amplifier will fail if "overloaded" by speakers. An amp can smoke a speaker, but the only way a speaker can smoke an amp is if the speakers do not provide enough resistive load to the amplifier, not too much. A high resistance speaker will perform pretty poorly, and may heat the speaker up, but the amp won't care as long as you don't exceed it's output value (which is pretty hard to do on modern amplifiers). On the other hand, if you don't provide enough of a resistive load to the amplifier then the amplifier can heat up and fry. One way people do this (accidentally) is by not knowing when to wire in parallel versus in series when using multiple speakers.

a reply to: Brotherman

Just make sure you use a hammer with a fiberglass / nylon handle and an insulated grip!

a reply to: Flyingclaydisk

but the only way a speaker can smoke an amp is if the speakers do not provide enough resistive load to the amplifier, not too much.

Quite right! Especially if a voice coil melts and becomes a dead short ... modern amps have protection against things such as this.

Back in the Sixties ... lol ... there was a series of (the first transistor amps) amps designed that if you unplugged the speaker while the amp was idling, the amp would self destruct. They did not stay on the market for very long!

Those first years were great.

P

a reply to: Flyingclaydisk

OK, if you want to get technical and split hairs, yes some of the statements are not 100% correct. See the contexts of the whole thread as your answer seem to be for a different thread where we can argue till the day is done. It was not intended for the educated and in my opening I stated it started out as a joker that turn into this after finding speaker wires in a plug circuit.

a reply to: ICycle2

No harm intended. Just some friendly clarifications.

originally posted by: Brotherman
sounds like you need a bigger hammer, I use hammers for all my electric problems.

Nonsense, explosives are more funner.

And they really impress the usual nay-sayers.

I, for one, have zero grasp of electricity, and therefore appreciate tutorials such as this. Thank you.
If I did have a grasp of electricity, I could light up a room. ;-)