300

[enireh]

I have a 320 amp service with two 200 amp panels. One of them needs to service the main house 300' away. I need a 200 amp disconnect that will handle 300 mcm

 

[augie47]

Burndy AYPO300 Pin reducer will solve your problem

http://www.ideadigitalcontent.com/files/NEURBRO/4213.pdf

 

[Michael15956]

Burndy AYPO300 Pin reducer will solve your problem

http://www.ideadigitalcontent.com/files/NEURBRO/4213.pdf

Augie, other than a code violation, what are the safety concerns with just timing the 300 to fit the lug? If timed, there is one less connection that can go bad.

 

[jumper]

Augie, other than a code violation, what are the safety concerns with just timing the 300 to fit the lug? If timed, there is one less connection that can go bad.

What is ampacity of a trimmed conductor?

 

[Dennis Alwon]

Augie, other than a code violation, what are the safety concerns with just timing the 300 to fit the lug? If timed, there is one less connection that can go bad.

You have the potential of over heating the cable at that point. I have seen it done many times but........

 

[augie47]

One of our members who is sharp on physics can probably elaborate, but Im told "trimming" is particularly bad in that the majority of the current carried by a conductor is carried by the outer strands. I can not testify to the validity of that.

 

[kwired]

Looking in Square D catalog their 200 amp safety switches have lugs that accept 300kcmil conductors, but it also indicates in there that there is only 312.6 bending space for 250kcmil.

I see the QBL breakers also accept 300 kcmil, but not certain if enclosure for a single breaker has enough bending space. They have a 2 pole only enclosure and a 2-3 pole enclosure and I am pretty certain the 2-3 pole enclosure is larger and possibly will have bending space for 300 where the 2 pole only probably does not.

 

[ritelec]

I posted a while back and was ( did) use # 8's for vd. It was going to be on a 20 amp circuit and going from the 8's to 12's at the breaker or device in the field isn't a problem.

Would reducing the 300's at the breakers (or a box before the breakers ) be an issue ?

 

[kwired]

I posted a while back and was ( did) use # 8's for vd. It was going to be on a 20 amp circuit and going from the 8's to 12's at the breaker or device in the field isn't a problem.

Would reducing the 300's at the breakers (or a box before the breakers ) be an issue ?

not an issue - but bending space still applies even if you have a reducing device on the end of the conductor - and actually should decrease bending space by the dimension of that reducing device.

If you entered from underground say on a 200 amp disconnect or breaker enclosure and had enough space along side of breaker or disconnect components to do the reduction then entered top side lugs with smaller conductors that worked for available bending space then no problem.

 

[ritelec]

Ok. I was thinking even box and reduce conductors outside of the enclosures
Enter the enclosures with the smaller conductors ??

 

[kwired]

Ok. I was thinking even box and reduce conductors outside of the enclosures
Enter the enclosures with the smaller conductors ??

I thought I covered both, with conditions for inside the disconnect/breaker enclosure.

 

[Michael15956]

One of our members who is sharp on physics can probably elaborate, but Im told "trimming" is particularly bad in that the majority of the current carried by a conductor is carried by the outer strands. I can not testify to the validity of that.

If true, then is makes sense.

 

[kwired]

One of our members who is sharp on physics can probably elaborate, but Im told "trimming" is particularly bad in that the majority of the current carried by a conductor is carried by the outer strands. I can not testify to the validity of that.

So if one is going to trim some strands they should trim inner strands