Basic Electricity For Homeowners

[Worth1]

Now if you were to get in a bind and needed to run a car radio tape player off 12 volt power in the house you would need this stuff.
I was in that bind and at the young poor age of 13 I did it.
I took a 6 amp 12 volt car battery charger and hooked it up.
What the devil is that buzzing noise??!?:
Well it was that dreaded AC ripple I talked about.
That buzz was unfiltered DC current the buzz is the polarity swapping 60 times a second.
Now how to filter it out.
I took a dead cant charge anymore car battery and ran my charger to it.
And then to the tape player.
This killed out all of the AC ripple and in effect I had a filter as a battery and capacitor which is used for a filter are a lot alike.
Yes I had a lot of crazy stuff in my room growing up.
Dried bugs and critter collections pet frogs strange mold experiments and electrical stuff and occasional controlled explosions and fires.
Worth

Wiring 4.jpg

[dmforcier]

A diode is a check valve in a way but I think it is still stupid to call it that.

No, that 's a good plumbing analogy. A check valve lets water flow in only one direction.

A diode lets current flow in only one direction.

When AC switches polarity, AC current wants to flow in each direction alternately. A single diode between an AC source and a load will cut the average current flow in half. The four-diode bridge arrangement essentially takes + and - halves and adds them together to get something like DC, but the addition isn't perfect; thus the remaining ripple.


Also, I think a transformer works for DC as for AC. The coils in a transformer are inductively coupled, so any uni-directional (DC) current will be reflected in the other coil (to make things very simple, ignoring ratios). [see below]

[Worth1]

Next the shunt trip breaker.
What is a shunt?
It is a short circuit.
Why do you want it?
Many reasons.
What does it do?
It purposefully trips the breaker for something it could be all of the power or just part of it by shorting it out to make it trip.
How does it work?
With a relay.
Lets say you have a breaker that will trip at 20 amps.
You take a relay that is rated for 50 amps.
This relay will activate at any voltage but lets say 24 volts.
But wait what is a relay?
A relay is a switch that activates by energizing it with a power source.
The power makes contacts open or close therefor sending or shutting off separate power to something else.

So here we go.
You take a wee little micro switch that is rated for lets say 100 mil amps.
It is wired into relay that will draw 50 mil amps but is rated for 50 amps on the contact side.
Take the right sized wire from the hot side of the breaker and wire it through the normally open contact of the relay on one side.
Take the neutral wire and wire it to the common side of the relay.
When the micro switch is closed and the relay energizes the big relay contacts close.
This shorts out the breaker and makes it trip.
This is how an ESD (emergency shut down) works.
This is what you see at the gas pumps that red mushroom button at every pump island or some place at that station.
If you see a runaway gas spill or a fire dont be afraid to hit that button.
It will shut off all of the pumps or should.
Some are fail safe if there is a loss of power to one part of the system they will close and shut stuff down so it has be fixed.
In other words the relay is energized all of the time, if it loses power the contacts close.

How can you get a runaway gas pump?
If someone drives off with the pump running and it rips the filling nozzle from the hose it will start spilling fuel everywhere.
They may have fixed this but I doubt it.
Worth

[Worth1]

Originally Posted by dmforcier

Also, I think a transformer works for DC as for AC. The coils in a transformer are inductively coupled, so any uni-directional (DC) current will be reflected in the other coil (to make things very simple, ignoring ratios).

There is no magnetic Flux /Field in DC current to make a transformer work.
Faraday's law of Electromagnetic Induction.
Worth

[dmforcier]

Back in the day computer rooms would have a big red switch to kill power to the racks in case something caught fire or whatever. We were told NEVER hit that Big Red Shiny Button! Of course, this made us curious and being OCD computer nerds we obsessed about what the button would do if hit.

So one day we took the cover off. Underneath were the main leads going to the power supplies. The Big Red Shiny Button was attached to a guillotine-like blade that would cut (and incidentally short) the main power circuit.

I bet your button could be reset a lot easier than mine.

[dmforcier]

Hmmph! Learned something today. Thanks.

There are "DC transformers" sold, but I found this:

For a transformer to work, the current in one coil has to somehow make current flow in the other coil and the circuit it's connected to. A DC current in one coil will make a magnetic field on the other coil, but a magnetic field by itself won't drive any electrons around. A CHANGING magnetic field, however, does create an electric force which will accelerate those electrons in the other coil into carrying a current. This process is described by Faraday's law of induction. You get a changing field from an AC current, since the current which makes the field is changing.

It's been a LONG time since my electronics courses...

[Worth1]

Originally Posted by dmforcier

Back in the day computer rooms would have a big red switch to kill power to the racks in case something caught fire or whatever. We were told NEVER hit that Big Red Shiny Button! Of course, this made us curious and being OCD computer nerds we obsessed about what the button would do if hit.

So one day we took the cover off. Underneath were the main leads going to the power supplies. The Big Red Shiny Button was attached to a guillotine-like blade that would cut (and incidentally short) the main power circuit.

I bet your button could be reset a lot easier than mine.

I know an idiot that shut down the main computers in Tulsa Oklahoma from the coast of Texas.
All he did was lift a wire.
It not only shut Amoco's computers down in Texas but the ones in Tulsa.
The idiot didn't know how to read contacts with a meter that see if they were closed or not with powered wire going to them.
Try as I might I could never get him to understand contacts wiring meters and relays.
He started out making more money than me because he said he worked with radar in the army.
I on the other hand was in the Marines and was assumed a stupid grunt.
They never even looked past Marine to the part where it said I went to 29 Palms school of electronics and communications.
All I was was a stupid Marine that did stupid pipe work.
The one day I was working with a guy doing fire alarm because he needed help.
He got called away and it was Friday.
I wanted to go home so I finished the job.
He got back and had a heart attack because he told me the stupid pipe guy not to touch anything.
I said just test it so we can go home he did and it all worked.

I was called in the office a day or two later and they handed me a circuit board and was asked what stuff was on it.
I told them everything.
They told me I knew more than the fire alarm guys they had hired.
Where did you learn this?
At home and the Marines.
How would a Marine know this?
You guys are stupid do you have any idea how many types of things the Marines do.
We even have our own Air Wing and fly jets.
The Army doesn't.
Then they asked me if I wanted to go into the fire alarm side of it.
I said let me think about it.
I came back and told them I wanted to do both pipe and electronics so that is what I did.
When I got my own van I had pipe stuff on one side and electronic stuff on the other.
If I got bored with one I would do the other.
My choice.
The stupid pipe fitter comment ticks me off to this day that that guy our boss made.
To this day wherever he is I still cant stand that jerk.
Pipe fitters aren't stupid.
Stupid people are stupid no matter what trade they are in even doctors.

Originally Posted by dmforcier

Hmmph! Learned something today. Thanks.

There are "DC transformers" sold, but I found this:

For a transformer to work, the current in one coil has to somehow make current flow in the other coil and the circuit it's connected to. A DC current in one coil will make a magnetic field on the other coil, but a magnetic field by itself won't drive any electrons around. A CHANGING magnetic field, however, does create an electric force which will accelerate those electrons in the other coil into carrying a current. This process is described by Faraday's law of induction. You get a changing field from an AC current, since the current which makes the field is changing.

It's been a LONG time since my electronics courses...

They have all sorts of crazy stuff out there now.
Inverter welders and so much more.

Peaking of induction.
I was with another guy all day working around some big time high voltage and I mean big time.
Our hairs were standing up on end.
The insulated conductors were as big as my legs and we were right on them.
He looked at his watch it was time to leave.

We packed up everything and got in my van.
I looked at the clock on the radio.'
It was two hours or so before time to go.
The electricity was so high it made his watch speed up.
No way was I gong to unpack and go back to work.

Worth

[dmforcier]

Originally Posted by Worth1

There is no magnetic Flux /Field in DC current to make a transformer work.
Faraday's law of Electromagnetic Induction.

Just thought of the perfect illustration for that:

All the power in an automobile is 12V DC. In order to fire a spark there is (usually) at least one transformer - the ignition coil. (My car has one per plug.) To induce the current in the secondary (plug-side coil) the system closes a contact/connection and applies voltage to the primary, causing current to flow in the primary coil. Then it opens the contact/connection, stopping the current flow.

IIRC, both event generate current in the secondary, but the point is, unless the circuit is open/closed, no spark. (In older ignition systems, the points did this job. Now it's all electronics doing the same job.)

[Worth1]

The coil cant run at that voltage all of the time it has to charge and discharged I think.

Well any who, what else is there to talk about?
Oh here is one I discovered.
When you buy a range it requires bigger wire and a breaker than a wall oven alone.
Or an electric cook top alone.
Reason is the circuit has to have enough power to run the cook top and oven at the same time.
When I bought my oven I checked on this to see if I could run it on an existing 240 outlet in the garage and I can.
The reason for this comment is just because it is a 220/240 outlet doesn't mean you can just run anything on it.
Check your spec sheet and wiring manuals or the plate on the back of the device before you move ahead.

Worth

[Worth1]

Even if you dont plan on doing anything yourself this thread and understanding terminology can help you greatly.
By knowing what is going on and how it works you stand a far better chance of not getting ripped off by a contractor.
That first call can mean everything.
Remember you are the boss not them you spec the job not them.
They work for you and they do as you tell them to do.

Know your prices and dont let them jack you up if you ask for better grade than what they use in a home.
If they do try to jack you up then it is a dead giveaway they are rip offs.
Don't pay them up front by all means.
Don't pay for their waste either.

An example is you know it will take 25 feet of wire to run from one spot to the next.
They buy a 200 foot roll of wire and they charge you for it.
If they do then by darn they better leave it with you or not charge you for it.
Materials mark up.
Yes there is that to consider to.
I always by company policy charged a 30% mark up on materials.
As far as I am concerned anything more is a rip off.

3 ways to pay.
Hard dollar AKA a set price contract.
Time and materials.
Time and materials not to exceed a hard set price.
Depending on the company each of of these can be good and bad.

I have done all three for refineries and chemical plants.
On my end I had to keep track of the time and keep records of everything I did every day and turn it in to the costumer and my company.

The time and materials not to exceed blew up in my face one time and the guy didn't want to pay us.
'The guy was a real jackass named George Oaks and nobody wanted to be around him.
He was always yelling and screaming at people.
And I dont mind dropping his name here.
Here is what happened I had to go under a building to run conduit and install fire alarm.

The salesman Larry Owens who died some time ago and I posted about it here gave me a chicken scratch drawing not to code that said so and so amount of aluminum conduit.
George the jerk had to come and shiff under the building every morning for explosive gas before we go go in.
My time started at 7:00 AM.
He didn't show up till 8:30 or 9:00 AM.
Then he had to sniff at noon and so on.
Well with his lateness it ran the job over on hours.
On top of that people at the office were tagging time on the job.
It amounted to 10,000 over.
Plus I put the job in to code, not Larry's BS idea of making money.
George came unglued and didn't want to pay even though it wasn't his money.
He said we were gone during certain times we were supposed to be working and so on.
Well there was a meeting and I had my records.

I had put down on those records everything we did and why.
I put down the time we waited on George to show up so we could go to work.
The time it took to get a work permit and so on.
The time and when we went to get parts.
Everything.
Then after it was all completed the 10,000 dollars was the exact amount of money that the office personnel tagged on to my job.
George didn't have to pay the extra 10K and my but was out of a sling.
Then the memo came out.
No one is to ever put time on my jobs ever except me and my helpers.
I had fought them on this for a long time and it finally bit them in the butt.
The office personnel were to only put time on the PM inspections people did not my hard dollar and T&M jobs.

Next time and materials.
This can be good if you know the guys doing the work.
It can be bad if you dont or they are screw offs.
What you will get is a quality product if the guys are good.
If not you can and many times will pay out the but for junk.
Next is phone calls to the guys on the job from the office about other work.
You dont need to be paying for this if they are on your clock.
I had this happen one time.
I told the guys if your boss keeps calling you about when you are going to be done I am going to call the office and complain.
It was a hard dollar job.

Hard dollar job.
This is where you pay a fixed price.
What you can and will get many times is shoddy work depending on the crew and the company.
Dangerous time saving shortcuts and all.

Know how to do the job the codes and the parts required.
Stay on the job and inspect every so often and dont be afraid to call out any shortcuts, mistakes or shoddy work.
It is your money your home your family and your safety.

Have that spec sheet for the job.
Don't let them put in sub par parts like anchors.
Have a pre-job meeting before they start and point out this stuff to them.
It is best to get it up front before the job ever starts.
Make them sign your contract on this.
Not Just theirs.
Most of these contractors will say sign here and go to work.
This is about the stupidest thing a home owner can do on a good sized job.

Do you need as general contractor?
Well yes and no.
It depends on what you want to pay what you know and what is allowed.
You will save a ton of money if you are the contractor if you have the skills to be one.
You have to know the codes and be willing to organize the job as it progresses.
May times you will have to call out bad work and have it redone at their cost not yours.
Refer to that spec sheet they signed.

Here is an example of one.

No wire shall be wasted and no wire shall be pulled no more than 6 inches out of the box.

Al boxes shall be 4x4 deep 1900 boxes.
All boxes shall be anchored to wood studs with than two 1 inch #8 wood screws.
All wiring shall be supported within 1 foot of each box.

All Light switches and receptacles shall be no less than spec or commercial grade so and so brand part number so and so.

Have a copy of every part and it s part number and pictuer for the contractor to see.
If a substitute is used it has to be of equal or better quality.

No open air splices all splices shall be made in so and so type box that will be accessible after job completion.

All wire in conduit for 120 VAC service shall be 12 gauge THHN stranded approved for wet conditions.
There shall be no more than 180 degrees of bend in conduit without a pull box in between.
There shall be no more than 40% conduit fill in each raceway.

All work shall be done in a professional workman like manner.

I could go on forever but you get the point.

If you have a crappy fly by night contractor show up and he sees this and reads it they will more than likely head for the hills.

Don't let these people tell you you dont need what ever or it is too much for your home.
It is your home you make the calls.

If I were to build my own house there wouldn't be one speck of ROMEX in it.
Everything would be in conduit and I would run it.

Worth

[Cole_Robbie]

Customers are attracted to the idea of knowing what a job will cost ahead of time. But the contractors I knew would say that in forming a bid, they figure time and materials to get a number...and then take that number and double it. If things go wrong, they still get paid for the extra time. If things go well, they just make more money.

[Worth1]

Originally Posted by Cole_Robbie

Customers are attracted to the idea of knowing what a job will cost ahead of time. But the contractors I knew would say that in forming a bid, they figure time and materials to get a number...and then take that number and double it. If things go wrong, they still get paid for the extra time. If things go well, they just make more money.

Don't even think about doing this with the Japanese companies.
You need to quadruple the price.
They will call you out for a bid then call you out to see if you can lower it yet again.
Then maybe just maybe they will take it.
It makes them feel good that they talked you down twice so you go too high to begin with.
The contractor that bids too low cant go down so backs out.
Once you gain their trust they wont even aske other people to give a price because they like your work,
You are locked in.
Oh yes and they like little freebies too.
Can you fix this, sure do it in an hour on the time of your hard dollar job you are on.
How much?
On the house.
Did it for years made tons of money.
They loved us.
Worth

[NewWestGardener]

You are right on! The white takes power to the switch. Then a black takes it to the light. Thanks to everyone's warning, I made sure I taped, wire-nutted, double-checked live/dead wires, and enclosed everything in the box when I installed the new LEd light, it's working!

Originally Posted by dmforcier

As Worth indicated, depending on the circuit it is legitimate to use any color wire. The black=hot and white=neutral arrangement is conventional, but not absolute. (Green must be ground, I think.)

However, best practice is that the installer "label" both ends of non-conventional color use. The 'best' way is to wrap some tape of the "correct" color around the insulation below the join. With white wires, the installer will often color the insulation with a black marker.

NWG, you can see that the installer used a white wire for hot. You could color it with a black marker as a reminder (especially if you disassemble to replace the box). Now you should be interested to find the other end and mark it, as its use as hot may not be obvious at the other end.

[Worth1]

See the thread not only helped someone it also helped them from getting hurt.
Worth

[Worth1]

I don't know if the thread has died or not.
But here is an observation.
They have wall outlets now with USB charging ports for your devices.
They have big transformers built into them.
They aren't green and use energy all of the time whether in use or not.
I also don't like the idea of a transformer buried up in my wall to burn up.
Box or no box.
Worth