kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
OP said the 600 amp switchboard was fed with aluminum.
Bus Rating Question
- Thread starter cdcengineer
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- Status
I referred to my earlier suggestion, which was to replace with 2x500 copper un-spliced from SDM.
cdcengineer
Senior Member
Alright. Let's try the link to the one-line:
https://www.dropbox.com/s/zfm5f46toc05p5u/CDC04242014.pdf
As you all point out, there is more than one way to solve this problem. I think the easiest would be to swap the enclosed 1200 A main with a 600 A. However we would need to track it down used since these SQ-D NAL's are obsolete. In this scenario, we woul either swing the 400A feeder for MDP into the SWBD, or eliminate MDP and just feed the new 200 A LP-4 from the spare 200 A fused bucket in the SWBD.
I am meeting a distributor out there to discuss material costs and review the scenarios. I appreciate the discussions and ideas you all have presented. I'll keep you posted
https://www.dropbox.com/s/zfm5f46toc05p5u/CDC04242014.pdf
As you all point out, there is more than one way to solve this problem. I think the easiest would be to swap the enclosed 1200 A main with a 600 A. However we would need to track it down used since these SQ-D NAL's are obsolete. In this scenario, we woul either swing the 400A feeder for MDP into the SWBD, or eliminate MDP and just feed the new 200 A LP-4 from the spare 200 A fused bucket in the SWBD.
I am meeting a distributor out there to discuss material costs and review the scenarios. I appreciate the discussions and ideas you all have presented. I'll keep you posted
cdcengineer
Senior Member
Ok, got out to the job and we took things apart and got a closer look. It was then, that the simplest solution presented itself. Not sure why I couldn't see it before, but the service originally consisted of only the SWBD. It was served through the adjacent CT can. What we plan to do, is remove completely the 1200 A main, leave the external CT cabinet and run new parallel 500 CU through a new wireway (deleting the old CT can, although we could just remove all the wires and replace with new) straight into the 600 A SWBD. The (3) handles are the service disconnect, and the 400 A MDP will now be fed from the 400 A spare in the SWBD. The loads on the entire service = ~ 400 A calculated with utility demand + 25% plus our new loads. We should be good to go.
FYI - we have to re pull conductors from the new CT to the SWBD only because the original (3) sets of 500 CU are run in only (2) conduits. I'm going off memory, but I believe this violates 300.3 & 300.20. We don;t need three sets, but we'll never pull just one out because the conduits are stuffed. It's a mess, but we'll get er cleaned up.
Thanks for the feedback.
FYI - we have to re pull conductors from the new CT to the SWBD only because the original (3) sets of 500 CU are run in only (2) conduits. I'm going off memory, but I believe this violates 300.3 & 300.20. We don;t need three sets, but we'll never pull just one out because the conduits are stuffed. It's a mess, but we'll get er cleaned up.
Thanks for the feedback.
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