secondary panel

[war_angel]

i would like to know if i can use a 100 amp panel with 100 amp double breaker as a secondary panel the neutrals connected to neutral bus, and the grounds connected to the ground bus,the cable feedind this panel is a #2aluminum,wire going to a 100 amp branch circuit double breaker in main panel which is 200 amps.

 

[barbeer]

Are there 4 conductors between the 2 panels? and are the neutral and ground bus connected in any way? What are the loads fed from this secondary panel board?

 

[LarryFine]

No, you can not. The 100a breaker is too large to protect the #2 al.

 

[Dennis Alwon]

i would like to know if i can use a 100 amp panel with 100 amp double breaker as a secondary panel the neutrals connected to neutral bus, and the grounds connected to the ground bus,the cable feedind this panel is a #2aluminum,wire going to a 100 amp branch circuit double breaker in main panel which is 200 amps.

Use a 90 amp breaker and you are good to go.

 

[war_angel]

secondary panel

Are there 4 conductors between the 2 panels? and are the neutral and ground bus connected in any way? What are the loads fed from this secondary panel board?

there are 4 condutors between the 2 panels 2 hot 1 neutral 1 ground on the secondary panel the neutrals wire and all the neutrals are connected to one bus and the ground wire and all ground wires are connected to ground.

 

[war_angel]

secondary panel

No, you can not. The 100a breaker is too large to protect the #2 al.

read nec table 310.20 this is a non continous load

 

[war_angel]

secondary panel

the nec table 310.20 #2 wire takes 106 amps non continous.

 

[don_resqcapt19]

the nec table 310.20 #2 wire takes 106 amps non continous.

That table only applies to messenger supported cable and does not apply to standard installations.

 

[infinity]

Use a 90 amp breaker and you are good to go.

If the cable feeding this panel is NM or SE he's limited to 80 amps.

the cable feeding this panel is a #2 aluminum

 

[JohnJ0906]

If the cable feeding this panel is NM or SE he's limited to 80 amps.

#2 AL SE is good for 90 amps under the '05 or previous NECs.
80 amps under the '08.

 

[war_angel]

secondary or auxilliary panel

secondary or auxilliary panel

there are 4 condutors between the 2 panels 2 hot, 1 neutral 1 ground on the secondary panel the neutrals wire and all the neutrals are connected to one bus and the ground wire and all ground wires are connected to ground.

the nec code table 310.15 says for 120/241 single phase dwelling services and feeders conductor type xhhw #2 can be used for 100 amp second panel

 

[stickboy1375]

the nec code table 310.15 says for 120/241 single phase dwelling services and feeders conductor type xhhw #2 can be used for 100 amp second panel

Thats only for the MAIN power feeder

 

[war_angel]

seconodary panel

seconodary panel

If the cable feeding this panel is NM or SE he's limited to 80 amps.

cable type is ser.

 

[JohnJ0906]

the nec code table 310.15 says for 120/241 single phase dwelling services and feeders conductor type xhhw #2 can be used for 100 amp second panel

Read the article that this table belongs to. 310.15(B)(6)

 

[infinity]

cable type is ser.

As noted, for SER under the 2005 you could go to 90 amps, 2008 only 80 amps.

 

[brother]

As noted, for SER under the 2005 you could go to 90 amps, 2008 only 80 amps.

What was the reason they felt they needed to lower the amps on this type of cable??

 

[iwire]

What was the reason they felt they needed to lower the amps on this type of cable??

To match the requirements of NM when SE is used in place of NM.

7-88 Log #2639 NEC-P07 Final Action: Accept
(338.10(B)(4)(a))
____________________________________________________________
Submitter: James M. Daly, General Cable

Recommendation: Delete the phrase “excluding 334.80” and change the
comma after “Article 334” to a period.


Substantiation: When Type SE conductors are used for interior wiring, as a
replacement for Type NM cable, the ampacity of the conductors should be the
same as permitted for NM cable since the insulations used are the same both
NM and SE conductors.

Panel Meeting Action: Accept

Panel Statement: This action will modify the action taken on Proposal 7-84.

Number Eligible to Vote: 14

Ballot Results: Affirmative: 14

 

[LarryFine]

When Type SE conductors are used for interior wiring, as a replacement for Type NM cable, the ampacity of the conductors should be the same as permitted for NM cable since the insulations used are the same both NM and SE conductors.

They should have done it the other way. :roll:

 

[iwire]

They should have done it the other way. :roll:

There were lab tests presented in previous cycles as the substantiation for the 60 C restriction on NM.

I have no doubt we will only see more restrictions, the new rules for conductors in raceways on roofs is one example.

 

[mthead]

secondary panel

There were lab tests presented in previous cycles as the substantiation for the 60 C restriction on NM.

I have no doubt we will only see more restrictions, the new rules for conductors in raceways on roofs is one example.

Am I right to assume you're referring to the changes mandated as a result of the increase in photovoltaic system installs in the last few years and all the adventures that they present?