26kv versus 13.5 kv

[davewants2]

I live in a small town on the ocean in S Florida. Our little town (30,000)has its its own utilty which has been run into the ground by idiots and deferred maintenance. Currently the system has 3 segments, 1 is 26kv, another is 13.5 kv and the remainder is 4 kv. A consultant brought in by the city wants to upgrade all to 26 kv. From my research I have found out that only 2 other cities in Florida (Key West and Jacksonville) exclusively use this voltage. I have no knowledge of high voltage distribution but it stands to reason that it is not the standard in Florida. Basically I would like some opinions on whether this is a good idea or will the 35 million in taxpayer (bond) money bring us a problem (oddball) system. Thanks in advance for your time.
David

 

[bob]

Re: 26kv versus 13.5 kv

Dave
Most utilities are moving away from 4 kv distribution. 13.2 and 12.46 kv are more of a standard that the 26 kv. I think that it is a good idea to move toward converting the system to one voltage. You don't have to do it all at once. I generally recommend a conversion when voltage problems occur. That usually occurs in the 4 kv section. The advantage of one voltage is the you don't have to maintain an inventory for the 3 voltages. How big an area do you cover?

 

[rick hart]

Re: 26kv versus 13.5 kv

I would suggest you go with a standard distribution voltage that is common with other utilities, whatever that might be. That would make sharing agreements easier in case you needed switches, transformers, etc. Ever need those in a hurry in S. Florida by the ocean?
13.2KV is at the top end of medium voltage (15KV)ratings, 26KV is a whole different classification with its own rules.

 

[davewants2]

Re: 26kv versus 13.5 kv

Bob
The city of Lake Worth is 6.5 sq miles. We are surrounded by Florida Power and Light who use 13.5 kv.

Currently the citizenry is beating down the doors at city hall trying to find out who is responsible for the mis-management of the utility. One of our options would be a sell-out to FPL. I think there is a chance that those incompetents in charge want to go to 26kv so that our system would not be compatible with FPL and thereby effectivly block that option.

 

[rick hart]

Re: 26kv versus 13.5 kv

I think there is a chance that those incompetents in charge want to go to 26kv so that our system would not be compatible with FPL and thereby effectivly block that option.

"When something does not make sense, look for the money."

 

[bob]

Re: 26kv versus 13.5 kv

The 13 kv system would serve the area just fine.
Keep in mind that when the next storm comes and the poles and wire are on the ground, it all belongs to you.

 

[hardworkingstiff]

Re: 26kv versus 13.5 kv

Sounds like you already know the answers. Believe in yourself.

 

[charlie]

Re: 26kv versus 13.5 kv

I wonder what the secondary voltage of the FPL substation transformers actually are (you need to find out). We call our system 13200Y/7620 V but our substation transformers are rated to put our 13.8 kV. This is less than 5% overvoltage from our nominal voltage and that will permit us to drop almost 10% before we are required to install voltage regulators. All of our equipment is 13.2 kV or 7.62 kV for distribution.

 

[beanland]

Re: 26kv versus 13.5 kv

I agree with others, stick with a common and widely used voltage in the surrounding area. This makes getting equipment easier and cheaper and may even allow multiple ties to FPL for emergency support. Avoid 26kV, it is an odd duck.