Okay so I don’t have emailed results yet however,
Our transformer passed all tests conducted.
-Doble
-TTR
-Megger
The tap dial is “marked” wrong as to indicating its place, but it in fact is set at “A” position for a 12470kva with current of 415/240.
We also tested the primary wire going...
Utility wasn’t too thrilled to go with rolling the phases, so I didn’t want to push that too hard on them.
I will be getting Megger, TTR, & Doble test done on Monday.
I will be sure to update the results.
@facengrpe
Apparently we are contracted for 12470kva
But have to tap all our xfrmr’s to 10800kva position to get the correct secondary.
Not sure if we are getting HV line spikes, but none of our other xfrmr’s are giving us issues.
@bacon4life & @waross
You both just gave me some good knowledge to go with,
@bacon4life
We don’t necessarily “choose” whether to put everything on a single phase or not, rather all possible slots are filled and whether the equipment operates properly or not, dictates how much amperage demand...
@waross
Quick answer to your follow up post, we use plastic conduit from riser to ground, i thermal gun those and all seem well.
To your initial reply (which I extremely appreciate this knowledge as I also get to learn):
<terminology/reply clarification>:
-“time to roll the connection”...
@waross
Oh I agree 100%
I had someone say we’d move equipment around to balance the load and my answer was immediately, “no!”
To me that’s a never ending objective with constant variable change. (As you said)
However a statement you made peaks a strong question or two.
At any given time...
@waross
That’s where I was concluding at as well after running through the facts and think out loud here.
Let me throw a variable in here to get your thoughts on.
A “full load” for us is normally 80% of the transformers max.
Also we have 2 other transformers of the same specs at this work...
@kiribanda
Great questions and kind of the same path I’ve been walking down:
400a breakers in unit (building), 3 breakers in each panel (this particular xfrmr supplies 4 units (buildings) so (12) 400a breakers being supplied by the xfrmr secondary (3ph w/ neutral).
On HV lines rated 12470kv...
@waross
3200 kva xfrmr
HV 12470 D (we have on tap E, as utility wasnt bringing in voltage for what we needed at “d”).
E tap is - 10800v 171.1a
Cutout fuse is 140amp
With partial load we’ve been okay, but full load blows the fuse on HV riser every time. We’ve done that 4 times in past week...
I have multiple transformers (1000kv, 2300kv, 3200kv)
Each are 3phase 415/240v
Each transformer powers multiple units. When I does amperage readings on each phase of the 400amp breakers I get various results such as:
91a/175a/235a
Could uneven phases like this be the culprit of making its...
