Question about Station service TX

[Sn00ze]

I am just informed that instead of a 50 kVA SST they sent us a 75 kVA station service transformer. Before proceeding i just wanted to ask the question to you guys.

I am thinking that as long as you dont change the fuse (200A) you dont have to resize the cables.

thoughts ?

 

[magoo2]

I agree with you. The 50 kVA rating is what you want but a larger size will work fine.

 

[marks1080]

Agree as well. If you already have the cables laid down and your design is for 50kVA load max, than you'll be fine. If you want to take advantage of the extra 25kVA in the future you may need to swap some cables/fuses.

 

[Sn00ze]

Thank you gents. I appreciate the input!

 

[waross]

It will work fine until the energization inrush takes out the fuses. This may not be the first time that it is energized.
The residual magnetism depends on the point on the wave that the current is interrupted, and high residual magnetism combined with energizing at the wrong point on the wave produces the maximum inrush current.
With few outages, the fuses may last for years before they get hit with the maximum possible inrush.
I would be looking for 200 Amp fuses that will withstand the maximum inrush of a 75 KVA transformer.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[GroovyGuy]

Hi Sn00ze,
Additional info required prior to anyone offering legit recommendations here.
If I had to guess the 50kVA transformer had the 200A fuses on the secondary, correct?
If I had to guess the transformer is a single-phase unit with a 240V secondary, correct?
What is the transformer's NPP data, (ie phase, voltages, size)?
What is the transformer's primary protection (ie Fuse, CB and it's current rating)?
Regards,
GG


"I have not failed. I've just found 10,000 ways that won't work." Thomas Alva Edison (1847-1931)