Substitute load bank for a diesel generator testing

[edsoneicc]

Hi! I have a 15 kVA single phase diesel generator with rated power factor of 0.8. For load bank testing, it should be tested with 15 kVA inductive load bank with power factor of 0.8. That equates to 12 kW load.

My question is, can substitute a 12 kW purely resistive load bank with power factor of 1? Also, would the results be equivalent and valid?

Thanks!

 

[kwired]

Hi! I have a 15 kVA single phase diesel generator with rated power factor of 0.8. For load bank testing, it should be tested with 15 kVA inductive load bank with power factor of 0.8. That equates to 12 kW load.

My question is, can substitute a 12 kW purely resistive load bank with power factor of 1? Also, would the results be equivalent and valid?

Thanks!

The prime mover sees 12 kW either way, but the generator sees more current in it's windings if the power factor is 0.8.

 

[ron]

Is this theoretical, or maybe a factory witness test?

Even for 2 & 3 MW generators we don't use resistive AND reactive load banks to come up with the 0.8 pf in the field, except at the factory test.

12kW in your example and call it a day.

I have a couple of space heaters in the garage you could borrow .....

 

[Ingenieur]

What will the genset power?
do you have a 12 kw pump avaliable?

but usually a 12 kw resistive load bank is all that is used

 

[edsoneicc]

Is this theoretical, or maybe a factory witness test?

Even for 2 & 3 MW generators we don't use resistive AND reactive load banks to come up with the 0.8 pf in the field, except at the factory test.

12kW in your example and call it a day.

I have a couple of space heaters in the garage you could borrow .....

Yes. This is about factory testing.

 

[edsoneicc]

The prime mover sees 12 kW either way, but the generator sees more current in it's windings if the power factor is 0.8.

I'm kinda confused with the factory test report for my generator.


The 220 V, 60 Hz generator is rated 0.8 power factor but what I see from the results is that it was tested using 12 kW purely resistive load since at 100% load, the output kVA is around 12 kVA. We know that if kW = kVA, then power factor = 1.

According to the nameplate, the rated current is 81.8 A from a power factor of 0.8. But at 100% load (which I assume is 12 kW), the current is only 55.9 A. With what you're saying, does it mean that if I use a 15 kVA inductive load bank of 0.8 power factor, I would get a 81.8 A at 100% load instead?

 

[Sahib]

The 220 V, 60 Hz generator is rated 0.8 power factor but what I see from the results is that it was tested using 12 kW purely resistive load since at 100% load, the output kVA is around 12 kVA. We know that if kW = kVA, then power factor = 1.

The prime mover was tested at full load and 10% over load. The generator was only tested at part load.

According to the nameplate, the rated current is 81.8 A from a power factor of 0.8. But at 100% load (which I assume is 12 kW), the current is only 55.9 A. With what you're saying, does it mean that if I use a 15 kVA inductive load bank of 0.8 power factor, I would get a 81.8 A at 100% load instead?

Yes. You need to refer to relevant standard, if any, for diesel generator testing for clarification.

 

[brian john]

Is this theoretical, or maybe a factory witness test?

Even for 2 & 3 MW generators, we don't use resistive AND reactive load banks to come up with the 0.8 pf in the field, except at the factory test.

12kW in your example and call it a day.

I have a couple of space heaters in the garage you could borrow .....

Had a government job they wanted reactive for a 20 KW unit.

Most customers balk at the price when they see the adder for reactive load banks

 

[Ingenieur]

The numbers do not compute
12 kw/15 va/0.8 pf/220 1ph does not equal 82 A

at 15 kva ~ 68 A

 

[Sahib]

The numbers do not compute
12 kw/15 va/0.8 pf/220 1ph does not equal 82 A

at 15 kva ~ 68 A

Yes but the size of the generator coupled to the primemover may be higher than 15 KVA.

According to the nameplate, the rated current is 81.8 A from a power factor of 0.8.