I'm surprised I haven't had to consider this before. Can you run parallel sets to the HV terminals on a dead front transformer? Wouldn't it need to have the provisions to support those connections? For example, if it's loop configuration and it only has the 2 inputs per phase, there's no way to bring parallel sets, because you need one for in and one for out. Correct? It's not like a spade air terminals where you can throw on multiple lugs.
Parallel Sets to Dead Front Transformer
- Thread starter bwat
- Start date
- Status
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
You could use a feed thru insert Or a load break junction I suppose. There are all sorts of separable connectors.Seems rare to need parallel conductors for MV...
15 kV Load Break Feed-Thru Bushing Insert | 215FTI | Hubbell Power Systems
Load Break Feed-Thru Bushing Insert, 200 Amp, 15 kV.
www.hubbell.com
Thanks for the links. Good to know that a solution exists. As far as the rarity, it hasn't really come up for me in years past, but how would you do a 600A 15kV underground feed with AL? Most ECs hate anything over 750kcmil, and I'll probably receive some choice words for even using 750s from some.
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
Yeah if you get into a lower voltage like 4160 it's not too too hard to get above 200A - but even that is 1.5MW. At 12.47KV it's over 4 meg....but 600 Amp dead break connectors are presumably pretty common in the utility world, and I do t know what they are cabling those with. Hopefully @Hv&Lv will chime in.
The use of a t will allow parallel conductors, and will get your conductors small enough to make most EC’s happy.
Just make sure your transformer is ordered with the correct bushing wells (amperage) and your not overloading them.
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
What type and size of conductors would utility typically use on 600 amp connectors where there is close to 600 amps of load?
Oh Wow…
thats 25 MW at our voltage.
our ENTIRE SYSTEM (43 substations, 48,000 customers) has 60 MW right now..
We use 750 AL for the feeders leaving out of the substations. Not for large loads, but to match our overhead wire as close as possible.
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
So is a UG POCO feeder often just 200 amp connectors?Oh Wow…
thats 25 MW at our voltage.
our ENTIRE SYSTEM (43 substations, 48,000 customers) has 60 MW right now..
We use 750 AL for the feeders leaving out of the substations. Not for large loads, but to match our overhead wire as close as possible.
On our newer stations the feeders leave the station UG for a cleaner and safer area then transition to overhead somewhere outside the fence.
I have ran some 750 parallel to a train yard but it was terminated using the terminations in the link and bolted to a live front.
The stackable T’s in the earlier link we used for some loop feeds, but they are perfect for parallel feeders.
Like I said earlier, you just have to be careful of the “funnel” that will generally be the weak point carrying maximum load, which is the bushing well.
This is true even for bolt on terminations. The bushing wells have to be able to handle the total amperage of the combined cables.
- Status