Service 600a 120/240 3 ph delta
phase a 170a
phase b 34 a
phase c 160 a
what will be the the effect to a 120/240 3 ph delta 130 kw generator
Fuel consumption, some wear and heating towards long-term failure. IMO, shouldn't have any effect approaching the limits of its design.Service 600a 120/240 3 ph delta
phase a 170a
phase b 34 a
phase c 160 a
what will be the the effect to a 120/240 3 ph delta 130 kw generator
A 130 KW genset is likely rated @.8PF so the line current would be 390 amps. I don't see a problem with the load you mention. Also, the major genset manufacturers make so called "long stack" generator ends when this is an issue. I've also seen using setups using a transformer to achieve better balance on the genset. This is one example of why these types of services are not so popular.Service 600a 120/240 3 ph delta
phase a 170a
phase b 34 a
phase c 160 a
what will be the the effect to a 120/240 3 ph delta 130 kw generator
PLR...
The Ampere-Imbalance-Factor (AIF) is about 70%. This factor results in Positive and Negative Sequence-currents of about 110A, and 80A, respectively. I'm sure the latter value far exceeds the generator's capability!
Can you provide phase-to-phase and phase-to-ground voltage measurements... loaded and unloaded (if possible)?
Regards, Phil Corso
Tom...
An excellent start is: http://users.encs.concordia.ca/~pillay/16.pdf
FWIW, I recall very little about symmetrical component analysis and likely just enough to be wrong most of the time. :happyyes:Would I be correct in saying, with respect to the voltage imbalance discussed, that the negative sequence component of the voltage would try to rotate the motor in the opposite direction? That gives some physical meaning to the term.
Phil...Smart $...
Yes. No damage to the stator winding of the generator. But damage will be done to the rotor winding due to excessive heat generated by -ve phase sequence current circulating in the rotor winding... the current levels are well below rated output levels, so I question whether the effects will lead to premature failure compared to MTBF.
I'll agree to extra heat. How can you establish heat will be excessive if you don't know the design parameters???Yes. No damage to the stator winding of the generator. But damage will be done to the rotor winding due to excessive heat generated by -ve phase sequence current circulating in the rotor winding.
Just a guess: the current at phase b is small approaching open circuit condition......I'll agree to extra heat. How can you establish heat will be excessive if you don't know the design parameters???
So you're saying a 3? generator cannot power a single phase load...???Just a guess: the current at phase b is small approaching open circuit condition......
You can certainly say that a 3? generator cannot deliver its full rated output power into a single phase load. Whether it can deliver more than 1/3 of its rated power into a single phase load is a different question and probably will end up involving both voltage regulation and mechanical stresses in addition to purely resistive losses.So you're saying a 3? generator cannot power a single phase load...???
More specifically a 120/240V 3? 4-W 130kW-rated generator cannot power (giving a benefit of a doubt) a 40kVA 240V 1? load.
You appear to be choosing words wisely knowing the proposed single phase load is less than 1/3 the rated output. One thing many forget is that in a delta configuration, 1/3 of a single-phase load's current is handled by the two indirectly-connected windings.You can certainly say that a 3? generator cannot deliver its full rated output power into a single phase load. Whether it can deliver more than 1/3 of its rated power into a single phase load is a different question and probably will end up involving both voltage regulation and mechanical stresses in addition to purely resistive losses.
I agree with both you and templdl that the best armed people to answer the OP question is the manufacturer... if not the only ones.A lot will depend on whether the manufacturer has designed all the windings with equal size wire or assumed that there will always be some extra load on the center-tapped 120/240 winding. It is best not to assume but instead to find out from the manufacturer. Typical specifications will describe the allowed imbalance and its effect on output power.