K-Factor A Concern If Supplying LED / CFL Lighting?

[crshears]

Hello all,

On the legacy steamship where I volunteer, I'm trying to move forward with providing single-phase isolation transformers for the on-board loads.

I know I have to factor in K in a big way on the one that will be supplying the VFD for the main engine turning gear; but what I'm uncertain of is how much K to factor in on the other, which will be supplying ~ 16 kVA of 120-volt load, most of it incandescent lighting with the addition of a few vacuum cleaners and such.

The hope is to eventually replace the vast majority of the incandescent bulbs with LED or CFL types [as long as historically authentic appearance can be maintained] in order to reduce power consumption, hence costs. The question is, will waveform distortion and/or harmonics engendered by supplying this type of lighting cause more heating/problems in this transformer than are remediated by the reduction in real power pass-through?

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

 

[waross]

On a side note: I remember the early discussion as to the fate of the engines. I am happy to learn that the engines will be able to be demonstrated on turning gear.
Congratulations to you and all of the other supporters of this project.

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

 

[crshears]

Hi Bill, and thank you! I'll pass your kudos along. We have actually now had two full summer seasons with the main engine on turning gear; it's been very well received.

The next project being pursued, and significant progress has already been made in this regard, is to get the steam-engine-driven steering gear operational. This one is going to be a more complicated undertaking, however, since there is no 'turning' facility for it; we will therefore have to employ low-pressure compressed air as the driving medium...but I digress; too much mechanical stuff for what's supposed to be an electricity forum.

Getting isolating transformers in place is proving to be a much greater issue than I would have imagined; progress is so slow I could almost be working for the government...

Do any of you have experience either good or bad in procuring transformers through Olsun or Temco? Any other supplier you'd recommend for 120/240 volt dry-type isolating transformers rated from, say, 20 to 40 kVA?

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

 

[Skogsgurra]

Your question: " will waveform distortion and/or harmonics engendered by supplying this type of lighting cause more heating/problems in this transformer than are remediated by the reduction in real power pass-through?" Has a very simple answer: No, it will not.

Power reduction is typically 90 percent. Losses in the transformer is from flux cycling, eddy currents and resistive losses in windings.

Let's say that it is a well-designed transformer where magnetic losses and resistive losses are just about the same. Then, a reduction of current with 90 percent reduces the 50% resistive losses down to 0,5% (current squared). The K factor - even if it is very bad - will not increase that 0.5% to more than 2 or 3& (incredibly bad K factor). So your transformer will have something like 47 percent less losses. And you save around 90 percent on the lighting bill.



Gunnar Englund

http://www.gke.org

--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

 

[crshears]

Thanks, Skogs; I greatly appreciate your help. Now to find a supplier...

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

 

[itsmoked]

For your project I would consider ebay. You can probably save about 70% over the cost of a new transformer. I just did - twice! Do however, megger the transformer before installing it.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[SceneryDriver]

Ebay is a great idea!

http://www.ebay.com/itm/20kVA-Singl...erruptible_Power_Supplies&hash=item4acf5ab6fd

SceneryDriver