Temporary Service
- Thread starter NYEIS
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pierre
Senior Member
- Location
- Westchester County, New York
Re: Temporary Service
Sorry I did not get back to this thread, but I took my wife away Friday and Saturday as her Valentines Day gift.... a real Casanova
Sorry I did not get back to this thread, but I took my wife away Friday and Saturday as her Valentines Day gift.... a real Casanova
- Location
- Massachusetts
Re: Temporary Service
Pierre I am not following you.
If I understand you correctly you are saying that any of the services I see on a regular basis that consist of a large panel (1000 to 3000 amps) board with 6 breakers all 800 amps or less are illegal.
Pierre I am not following you.
If I understand you correctly you are saying that any of the services I see on a regular basis that consist of a large panel (1000 to 3000 amps) board with 6 breakers all 800 amps or less are illegal.
jwelectric
Senior Member
- Location
- North Carolina
Re: Temporary Service
Originally posted by iwire:
Pierre I am not following you.
If I understand you correctly you are saying that any of the services I see on a regular basis that consist of a large panel (1000 to 3000 amps) board with 6 breakers all 800 amps or less are illegal.
- Location
- Massachusetts
Re: Temporary Service
I was focused on this.
If we need a main in the panel it is not because the branches do not disconect the SECs from the premises, if we need a main it is because of two reasons.
1)L&A Panel OCP
or
2)We have more than 6 throws of the hand.
Bob
Hi Mike, for now forget about the distentions between panel boards. (Which I am well aware of)
I was focused on this.
Again forgetting about the need for a main in L&A panels for a moment I am confused why Pierre would say these breakers do not disconnect that premises from the service conductors.
If we need a main in the panel it is not because the branches do not disconect the SECs from the premises, if we need a main it is because of two reasons.
1)L&A Panel OCP
or
2)We have more than 6 throws of the hand.
Bob
david
Senior Member
- Location
- Pennsylvania
Re: Temporary Service
Bob,
I am well aware of Don?s knowledge and have the most admirable respect for him.
I did however like it better in the old days when service conductors where protected at not more then their combined rating + rounding up to the next higher when under 800 amps when OC device and rhe ampacity of the conductor did not match
Now the only protection for the service conductors comes in the form of design and the code does require over load protection in that form
[ February 19, 2006, 11:04 AM: Message edited by: david ]
Bob,
I am well aware of Don?s knowledge and have the most admirable respect for him.
I did however like it better in the old days when service conductors where protected at not more then their combined rating + rounding up to the next higher when under 800 amps when OC device and rhe ampacity of the conductor did not match
Now the only protection for the service conductors comes in the form of design and the code does require over load protection in that form
[ February 19, 2006, 11:04 AM: Message edited by: david ]
- Location
- Massachusetts
Re: Temporary Service
But we are each entitled to our own opinions.
Follow me for a minute.
Think of a 5 family building with a house meter.
Because of the way we calculate the load per 220 the actual connected load has the potential to overload the service conductors.
The only thing that keeps that from happening is the unlikely occurrence of all the families running their HVAC, cooking and drying appliances all at the same time.
The conductors can be overloaded even if I design it to NEC minimums, there is no protection from that.
David I just can not agree with that, it is not protection it is just design no more.
But we are each entitled to our own opinions.
Follow me for a minute.
Think of a 5 family building with a house meter.
Because of the way we calculate the load per 220 the actual connected load has the potential to overload the service conductors.
The only thing that keeps that from happening is the unlikely occurrence of all the families running their HVAC, cooking and drying appliances all at the same time.
The conductors can be overloaded even if I design it to NEC minimums, there is no protection from that.
- Location
- Illinois
- Occupation
- retired electrician
Re: Temporary Service
Rick,
Don
Rick,
Article 450 has nothing to do with the required protection of conductors, panels or any equipment other than transformers. The issue in this thread is not the protection of a transformer.
Don
Re: Temporary Service
Don, That wasn't my point. My point is that secondary conductors are actually service conductors and fall under 230.71.and when using a panel board as service equip.,The provisions of 408.36 excep.#1 allow the use of not having individual protection when the ampacities of all the brkrs. are not greater than the rating of the panel.
This has been common practice,Finding the exact rules allowing it ,is always a challenge.
Rick
Don, That wasn't my point. My point is that secondary conductors are actually service conductors and fall under 230.71.and when using a panel board as service equip.,The provisions of 408.36 excep.#1 allow the use of not having individual protection when the ampacities of all the brkrs. are not greater than the rating of the panel.
This has been common practice,Finding the exact rules allowing it ,is always a challenge.
Rick
- Location
- Illinois
- Occupation
- retired electrician
Re: Temporary Service
Rick,
Don
Rick,
That exception does not permit that. As I stated before, that exception only applies when the panel is served by a feeder, it does not apply when the panel is served by service conductors. The exception requires line side overcurrent protection for the panel. You cannot provide overcurret protection at the load end of the supply conductors. You can only provide overload protection at the load end of the conductors. There is no code compliant way to install a lighting and appliance branch circuit panel unless you provide overcurrent protection on the supply side of the panel. There are only two ways that this can be done. One, the panel is supplied by a feeder that has an overcurrent device with a rating equal to or less than that of the panel, or two, use a main breaker in the panel. Again, there is nothing in Article 230 that modifies the requirement that a lighting and appliance branch circuit panel have overcurrent protection on its supply side. Just because it has always been done that way or just because everyone does it that way does not make it code compliant.
Don
- Location
- Illinois
- Occupation
- retired electrician
Re: Temporary Service
Rick,
Don
Rick,
What? I don't understand that statement. What secondary conductors are service conductors?
Don
david
Senior Member
- Location
- Pennsylvania
Re: Temporary Service
Bob.
Somewhere the Code says the service is sized to the actual or calculated load whichever is greater can't find it right now though
connected to calculated
[ February 19, 2006, 12:56 PM: Message edited by: david ]
Bob.
Somewhere the Code says the service is sized to the actual or calculated load whichever is greater can't find it right now though
connected to calculated
[ February 19, 2006, 12:56 PM: Message edited by: david ]
jwelectric
Senior Member
- Location
- North Carolina
Re: Temporary Service
Hello Bob,
Hope everything is going alright with you.
I think what Pierre is trying to say is that any single pole breaker from one to six that is being used for the service disconnect would be a violation of 230.71(B) as referenced by the FPN.
I know that a Fine Print Note is not enforceable but and section of the code that is referenced in that Fine Print Note is enforceable. The FPN found in 230.71(B) refers the reader to 408.36(A) and 430.95 where both sections tell us that a main disconnect is required.
Should there be any questions as to what would constitute ?Suitable for use as service equipment? read this
Hello Bob,
Hope everything is going alright with you.
I think what Pierre is trying to say is that any single pole breaker from one to six that is being used for the service disconnect would be a violation of 230.71(B) as referenced by the FPN.
I know that a Fine Print Note is not enforceable but and section of the code that is referenced in that Fine Print Note is enforceable. The FPN found in 230.71(B) refers the reader to 408.36(A) and 430.95 where both sections tell us that a main disconnect is required.
Should there be any questions as to what would constitute ?Suitable for use as service equipment? read this
jwelectric
Senior Member
- Location
- North Carolina
Re: Temporary Service
Would you explain where it recieves it current from.
Would you explain how conductors of a Separately Derived System and service conductors are the same.
Can you explain what is ment by "Separately Derived System"?
Would you explain where it recieves it current from.
Would you explain how conductors of a Separately Derived System and service conductors are the same.
Re: Temporary Service
OK, In the true definition of service,these xfrmr conductors are not considered service conductors, they are feeder conductors by definition.However the overcurrent device is allowed to be as stated in (430.3(B)note 2.So in the case of xfrmr secondary conductors,either 1 MB or up to six with restictions.
I can't see why 408.36 excpt. #1 would'nt apply when 230.71 FPN is referring you to it when the service disconnect is a panelboard.whether the panelboard is fed from a feeder from a xfrmr secondary, or service conductors, the NEC is allowing it.
Rick
OK, In the true definition of service,these xfrmr conductors are not considered service conductors, they are feeder conductors by definition.However the overcurrent device is allowed to be as stated in (430.3(B)note 2.So in the case of xfrmr secondary conductors,either 1 MB or up to six with restictions.
I can't see why 408.36 excpt. #1 would'nt apply when 230.71 FPN is referring you to it when the service disconnect is a panelboard.whether the panelboard is fed from a feeder from a xfrmr secondary, or service conductors, the NEC is allowing it.
Rick
- Location
- Massachusetts
Re: Temporary Service
David I have never seen that, I have seen 230.90(A) Exception 3 that simply requires the service conductors to exceed the calculated load.
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