2 lines 1 load 1 circut=wrong?

[Mr.MOD]

i was told by 2 masters that this is ok and im still not convinced
there is a bath fan being controlled by 2 timers 1 in a closet(24hr) and 1 in the bath( 60 min) both are being fed by the same branch circut, however when 1 is on and the other is off there is 120v on the load side of the other and vice versa. this just seems really wrong. any code ref would be greatly welcomed

 

[iwire]

i was told by 2 masters that this is ok and im still not convinced
there is a bath fan being controlled by 2 timers 1 in a closet(24hr) and 1 in the bath( 60 min) both are being fed by the same branch circut, however when 1 is on and the other is off there is 120v on the load side of the other and vice versa. this just seems really wrong. any code ref would be greatly welcomed

If one, or both are off I don't see any violations.

If both are on we could ague that it is a 310.4 violation.

 

[hillbilly1]

Is the 60 minute timer an overide during the off period of the 24 hr clock? Sounds like a simple override, and since its the same circuit, no power would be on the load terminals if the breaker was turned off. Simple parrelelling of the contacts. Done all of the time in motor controls.

 

[480sparky]

I don't see a violation. It's taking the same circuit through two controllers (the timers) to feed a single load.

Done all the time with DPST switches turning on the exhaust fan shared between the Mens' & Womens' restrooms.

 

[hillbilly1]

If one, or both are off I don't see any violations.

If both are on we could ague that it is a 310.4 violation.

Thats an interesting take on it, somewhat arguable, not really what that article intends, but for arguments sake the switch legs of the override switch could be landed across the contacts of the time clock, hence conductors would no longer be in parrelell, only contacts.

 

[iwire]

I don't see a violation. It's taking the same circuit through two controllers (the timers) to feed a single load.

That is not IMO what the exception to 310.4 allows.

I agree that the switches are controllers but the circuit is not a control circuit supplying contactors, solenoids relays or other similar control devices.

Done all the time with DPST switches turning on the exhaust fan shared between the Mens' & Womens' restrooms.

Yes it is done all the time, still a violation of 310.4. :smile:

 

[resistance]

I responded in the other thread, but to add. Not the best install in my book.

Good point raised by Iwire. Seeing that the homeowner may set the timers worng, I can agree that it would be a violation 310.4.

 

[Mr.MOD]

thank you all for the fast replys and sorry for the re-post guess i'll point out 310.4, the 24hr timer is set to close at intervals daily and the 60 min timer is when ever ho wishes

 

[iwire]

thank you all for the fast replys

Your welcome and welcome to the forum.

As has been mentioned it is a pretty common situation.

As far as load terminals being hot when the switch is open I only know of one NEC section that addresses that and it specifically has to do with solar panel installations.

 

[electricman2]

Just connect the 60 minute timer across the contacts of the 24hr. timer. :wink:

 

[benaround]

So, this would be your basic 60 min. violation ?

 

[frank_n]

That is not IMO what the exception to 310.4 allows.

I agree that the switches are controllers but the circuit is not a control circuit supplying contactors, solenoids relays or other similar control devices.

I agree with Iwire, this is NOT a control circuit.

Also, Exception 1(a) requires the conductors to be in the same raceway or cable. If one timer is in the closet and the other in the bath, are they in the same raceway or cable?

Frank N

 

[crossman]

Well, I apparently have been in an argumentative mood since yesterday.

I am totally missing the line of reasoning in this thread. As far as I can see, there is no violation of the main body of 310.4. Forget the exceptions, they don't even remotely apply. The conductors in this arrangement can in no shape or fashion be considered to be in parallel.

Maybe I am being dense. Can someone draw a diagram and show that they are in parallel? My thought is that a closed switch does not take two conductors and make it into one conductor in a manner that would violate 310.4. Two conductors in series with a switch between them is still physically two conductors even though there is continuity from one conductor to the other.

There may be some issues with 300.3(B) but judicious routing of the ungrounded and grounded conductors will take care of that.

 

[crossman]

Is this what we are talking about? If so, I do not believe that the red and black conductors are in violation of 310.4 if both switches happen to close at the same time.

If this isn't what we are discussing, then please tell me to "SHUT UP".

 

[Dennis Alwon]

Well, I apparently have been in an argumentative mood since yesterday.

Agreed, but isn't it fun.:grin:

Maybe I am being dense. Can someone draw a diagram and show that they are in parallel?.[/quote]


Feed to one switch then run a 3 wire to the 2nd switch and a 2 wire up to the fan. This is not a 3 way -- the neutrals pass thru both boxes. The red is the switch leg for the first timer and ties to the switch leg in the 2nd box which is tied to the fan. The power feds both switches.

When both switches are on the power will travel on the red and black wires back to the first switch.

Edit: I won't tell you to shut up. Yes that's it.

 

[480sparky]

.....When both switches are on the power will travel on the red and black wires back to the first switch.....

Back to the first switch??????

 

[crossman]

Hey Dennis:smile:. Yep, the arguing (well, let's call it civil disagreement) has been fun.

So my diagram is what we are discussing?

Do you feel that, with both switches closed, the red and black conductors are in parallel in a manner that violates the intent of 310.4?

 

[benaround]

IMO, you can't have a part time parallel conductor, it's either a parallel

conductor ( electricly joined at both ends ) or it's a conductor in parallel with

another conductor ( not electrically joined at both ends ) and in this case the

latter fits the bill. IMO, It would be hard to make it a violation that could

stand up for itself.

 

[iwire]

Is this what we are talking about?

It is.

If so, I do not believe that the red and black conductors are in violation of 310.4 if both switches happen to close at the same time.

If that was the case 310.4 would not need the exception for that exact scenario with control circuits.

 

[chris kennedy]

If both are on we could ague that it is a 310.4 violation.

310.4 Conductors in Parallel.
(A) General. Aluminum, copper-clad aluminum, or copper conductors of size 1/0 AWG and larger, comprising each phase, polarity, neutral, or grounded circuit conductor shall be permitted to be connected in parallel (electrically joined at both ends).

Are they joined at both ends?