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#140961 05/24/04 06:33 AM
Joined: May 2004
Posts: 16
T
Text Offline OP
Junior Member
Is there such a provision wherein if your computed load exceeds 10,000 Watts, the conductor & overcurrent protection shall be rated not less than 38.0 sqmm. and 100AT respectively?

#140962 05/24/04 07:15 AM
Joined: Sep 2003
Posts: 650
W
Member
Of course not. 10000W is only 500V on a standard 20A constant current circuit. 2.5mm^2 conductors are sufficient for a 20A circuit.

UEC requirements state that the overvoltage protection shunt be set at no less than 600V, and that all wiring devices be rated to properly short 600V when loads are removed.

I don't understand your question about 'overcurrent protection'. In a constant current system, you don't get over-current. Instead open circuit faults cause excessive voltage; that is why you use overvoltage shunting devices; they safely short out the circuit in the event of an open, preventing dangerous overvoltages.

*grin*

Seriously, Text, you have made the mistake of thinking that everyone on the net is from the same country and using the same electrical code as you. In addition, even when the code version is known, you would also need to describe the context in which you are applying it. What voltages are you talking about, what sort of load is being supplied, what sort of operational duty cycles, etc.

I doubt that you are working with constant current DC circuits, but such things are _possible_, fun to BS about, and sometimes similar to systems that actually do show up (runway lighting, eg). Without knowing the context of your question, it is almost meaningless.

Where are you located?
What code do you use?
What voltage will be used to supply the load?
What are the characteristics of the load?

-Jon

[This message has been edited by winnie (edited 05-24-2004).]

#140963 05/24/04 08:38 AM
Joined: Jan 2003
Posts: 4,391
I
Moderator
Jon LOL.

Text welcome to ECN, Jon is correct you need to give more info.

Someone here will always try to help out [Linked Image] fill in some details and you will probably find your answer.


Jon I see you are from Boston drop me an email maybe we have worked in the same areas.

Bob


Bob Badger
Construction & Maintenance Electrician
Massachusetts
#140964 06/04/04 06:41 AM
Joined: May 2004
Posts: 16
T
Text Offline OP
Junior Member
Where are you located?
-Philippines.
What code do you use?
-US(NEC)
What voltage will be used to supply the load?
-230V; 1Ø;
What are the characteristics of the load?
-Typical residential.
Thanks again.

#140965 06/04/04 10:43 AM
Joined: Sep 2002
Posts: 1,498
Likes: 1
C
C-H Offline
Member
I will take the opportunity to ask if 230V is the nominal voltage in the Philippines?

10 000 W @ 230V is only about 45A. It seems costly to require 100A conductors for this, but I'm not familiar with the NEC and I'll leave the code sections to the Americans.

#140966 06/04/04 11:09 AM
Joined: May 2001
Posts: 717
G
Member
Article 230-79 (c) (99 Code) - One Family Dwelling - For a one-family dwelling, the service disconnecting means shall have a rating of not less than 100 amperes, 3-wire.

230-79 (c) (96 code) - One Family Dwelling -For a one-family dwelling, the service disconnecting means shall have a rating of not less than 100 amperes, 3-wire under either of the following conditions: (1) where the initial computed load is 10 kVa or more, or (2) where the initial installation consists of six or more 2 wire branch circuits.

That may be what you're looking for.

#140967 06/04/04 11:37 AM
Joined: Aug 2001
Posts: 7,520
P
Member
Just one point to check: Are there any local variations to the code which might override the 100A minimum requirement?

The minimum service-requirements expected in America are often quite a bit higher than in many other countries.

#140968 06/04/04 12:13 PM
Joined: Sep 2002
Posts: 1,498
Likes: 1
C
C-H Offline
Member
Quote
The minimum service-requirements expected in America are often quite a bit higher than in many other countries.

Paul, you have just been nominated to the "Understatement of the Year Award" [Linked Image]

#140969 06/07/04 04:39 AM
Joined: Jul 2002
Posts: 8,407
Likes: 2
Member
Watch out C-H,
The year hasn't ended yet!. [Linked Image] [Linked Image]

#140970 06/07/04 05:50 PM
Joined: Aug 2001
Posts: 7,520
P
Member
Quote
Paul, you have just been nominated to the "Understatement of the Year Award"
[Linked Image]

You know that we British have a reputation for understating things....

There were probably those who described the events of 1776 as "That little problem with the Colonists" [Linked Image]


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