wiring terms

[electrics]

Hello i wonder how u call the conductors in a wiring installation, for example you will wire ur home, there will be a service panel at the entrance of ur building, from this panel comes a conductor named "feeder" true? this conductor comes to your storey panel in which there are overcurrent devices, from this overcurrent devices go out branch circuits true?? but if there are many luminaires and receptacles in your storey it is uneconomical to assign a branch circuit to every outlet one of these branch circuits true? so is there any distinguishing name to make out that the branch circuit has many outlets not only one? as far as i know in french they say ligne= line= branch circuit and sortie = conductors from branch circuit to the outlets , what about "circuit" here , note pls not" branch circuit" are they different ?
i cant understand exact meaning of "feeder", pls give me a brief explanations...

 

[Dennis Alwon]

You seem to have the basics down. Here is the NEC def. of feeder

Feeder. All circuit conductors between the service equipment, the source of a separately derived system, or other power supply source and the final branch-circuit overcurrent device.

In other words the conductors from your main distribution panel to other panels are called feeders. The last overcurrent device to the lights, recep. etc is a branch circuit. Or if you will...

Branch Circuit. The circuit conductors between the final overcurrent device protecting the circuit and the outlet(s).

There is little difference between a feeder and a branch circuit in some situations. If I run conductors from a main panel to a disconnect that has OCP then that wire is a feeder. If the disconnect is just a safety switch- no OCP then the same wire becomes a branch circuit. Odd huh

 

[electrics]

yes these are what i said above, what i cant understand is if branch circuits might have more than one outlet? i also dont use nec in my country, just trying to learn better, i think what i described above is not contradictional with urs also..also there are some more questions above, pls take it into consideration...

 

[electrics]

also i wonder what does handle tie means?

 

[Buck Parrish]

Bonjur, oui ll y a, a circuit to one outlet is a dedicated branch circuit -
Handle ties - are used to tie breakers together for a two pole or a multiwire branch circuit.

Multi wire branch circuit - ll y a 2 circuits on one neutral..

Au Revoir

 

[electrics]

is there any picture of it? or is it just the name of the technique?

 

[electrics]

ı GOT İT from net here you are...
Handle ties provide an acceptable method of linking operating handles of several single-pole circuit breakers together so they'll switch the tied circuit breakers together.

 

[Dennis Alwon]

ı GOT İT from net here you are...
Handle ties provide an acceptable method of linking operating handles of several single-pole circuit breakers together so they'll switch the tied circuit breakers together.

That is correct. Normally one would use a dp breaker but if there are 2 sp breakers available then you can use a handle tie so that both phases are disconnected at the same time.

Sharing a neutral can be dangerous in certain situations.

 

[Strahan]

That is correct. Normally one would use a dp breaker but if there are 2 sp breakers available then you can use a handle tie so that both phases are disconnected at the same time.

Sharing a neutral can be dangerous in certain situations.

Dennis,
Came across your pic while surfing through some old threads. Question wouldn't we have 240V across both loads? In the pic it states across load 2. I don't see how load 2 can have 240v dropped across it depending on the resistance of each load it can't be determined how much voltage is dropped across load 2. Sorry if I'm nitpicking but I printed this out to hang in our shop for the electricians to see and of course the questions started coming my way.

 

[480sparky]

Dennis,
Came across your pic while surfing through some old threads. Question wouldn't we have 240V across both loads? In the pic it states across load 2. I don't see how load 2 can have 240v dropped across it depending on the resistance of each load it can't be determined how much voltage is dropped across load 2. Sorry if I'm nitpicking but I printed this out to hang in our shop for the electricians to see and of course the questions started coming my way.

The illustration shows 240v impressed across two loads in series. How much voltage the indivual loads is actually impressed depends on their resitances. If they're close to the same, they'll be close to 120v each. The farther apart the resistance values get, the farther apart the two voltages will get....... but the two will still add up to 240v.

 

[LarryFine]

Handle ties provide an acceptable method of linking operating handles of several single-pole circuit breakers together so they'll switch the tied circuit breakers together.

Just to add to this, the handle tie qualifies for manual operation, but 2p and 3p loads require an 'internal common trip' mechanism. They would operate together even with the handle-tie removed.

I used to say "It says 'common internal trip' on the handle, but it looks external to me. Who are they kidding?" Then I separated the cases of a 2p breaker one day, and a little rectangle of phenolic fell out.

Some 1p breakers have a hole on one side of the case with what looks like a screw slot in it. If you twist it with a screwdriver, the breaker will trip. 2p and 3p breakers link those slots with little phenolic rectangles.*


* Or, at least the one I split did.

 

[UBG]

2p and 3p loads require an 'internal common trip' mechanism. They would operate together even with the handle-tie removed.

I was reading this thread to research the internal common trip requirement, and I beg to differ with this as a blanket statement. NEC 220.20(b)(2) (older versions; apparently in the 2008 version it is 220.15(b)(2), although I don't yet own a copy to veryify this :roll the internal common trip is NOT required provided:

1. the handle ties are "approved"
2. the system is grounded and
3. the load is single phase or 3-wire DC

220.20(b)(3) contains permitted exceptions for certain 3-phase and two-phase circumstances.

I found other threads here supporting this; perhaps I'll reference them later...

 

[UBG]

link to related thread

link to related thread

This thread discusses handle ties vs. internal common trips:
http://forums.mikeholt.com/showthread.php?t=94069&highlight=240.20(b)2