What does it being primary, or secondary for that matter, have to do with it? Since when does the ampacity of a conductor depend on being primary or secondary.Only if its primary
What does it being primary, or secondary for that matter, have to do with it? Since when does the ampacity of a conductor depend on being primary or secondary.Only if its primary
ehh!... the secondary is a 4-wire system. Where ya gonna put the neutral and ground?Per my Ugly's, you can fit four #3 copper Teflon (TFE) conductors in a 1" PVC. Now you can pull from end to end, have 100A rating at 75C. It is probably not cost-effective though!
What does it being secondary have to do with it? It's a 3? 4-wire [assuming separately derived] system. I do not think the load on the system compels the neutral to be counted as a CCC. So it's 3 CCC's, a neutral, and a ground. No multiconductor derating necessary.
Take a look at Table 310.13. You can't use TFE for this application.Per my Ugly's, you can fit four #3 copper Teflon (TFE) conductors in a 1" PVC. Now you can pull from end to end, have 100A rating at 75C. It is probably not cost-effective though!
The tap boxes should be as far away as possible from the disconnect and the panelboard.[/QUOTE]
...Unless they plan on using a type Z
For a 100A feeder, the minimum size grounded conductor is #8... same as the minimum size EGC. Refer to 215.2(A)(1)... after exceptions... second to last paragraph.They can, 3 #3's & 1 #8; oops no neutral. 3 #3's 1#14 & 1#8
No, I think they are not... they are likely proposing to install a non-compliant system. Whether knowingly or not, is anybody's guess.You really think "plenty of the other electrical contractors" are using a tap box arrangement in their design. They could be I suppose but not likely.
That's why I asked if this job is subject to a plan review and/or inspection.I think the engineer is doing a disservice to their client by not designing this installation, but who knows what their relationship is anyway. The contractor really doesn’t have to remain in business after installing and journeymen can leave the trade meaning the responsibility is lose to leave the design up to the contractors, especially while the engineer is adamantly pressing the limits. This is a design build, but probably lacking submitting the design so its more just do what your supposed to do and don’t be wrong.
Questions:I think I have them sold on the xfrmr in the kiosk but what is the smallest KVA transformer and feeders I can use for a 100 amp panel? According to the calcs I have a con. load of 67.29/ dem. load 58.32. Remember- the primary has to fit in a 1" PVC and we will want the secondary as big as possible but there is a serious space issue in this little kiosk. Can you guys give me your opinion on what is the most ideal app. for this situation? Thanks
But, as I posted above, the connected and demand loads are: "con. load of 67.29/ dem. load 58.32.".
They are calling for a 30 circuit MLO panel with a bus rating of 100a.. BUT I know that I will have to provide a disconnect means to the xfrmr in the kiosk because the existing disc. is in another tenant's space 150' away. This is going to require even more room.
I presume by this that you mean 67/58 amps 3 phase at 208V, rather than single phase load, 480V load, or kva? I belive that was the crux of Smart$'s question.
Your transformer requires secondary protection.
-Jon