Generator PTO Generator - Lights Flicker

[teg33]

I just purchased a Tiger PTO 10kW Generator and put it behind my Kubota B2400 tractor. It ties through a transfer switch into a subpanel of my critical house circuits. The setup works fine with one exception, sometimes there is a noticeable flicker in the incandescent lights. The problem is worse under light loads and seems to diminish as you increase the load. In some cases, if you reduce the throttle a bit and then return to rated speed/frequency the problem diminishes. The volt and frequency meters all look good and an external power quality meter reading shows the Voltage THD is within/near the specified limit of 5%.

Anyone else see this problem with flickering lights on a PTO generator?

 

[kubotaman68]

You are completely disconnected from the public utilities yes? I think that a b 2400 is marginal for 10 kw . I use a 12 kw behind my neighbors L3430 when the power goes out and i have no flicker except when things are being switched on in series

 

[teg33]

Yes, I am completely disconnected from the utility. I also realize that I probably cannot get a full 10kW out of the B2400, however, I'm not running anything greater than about a 7kW load.

 

[JoeR]

Could be the A/C sinewave is not clean. You could have some noice induced or grounding issue from static build up on the generator. If you have an O-Scope you could see the signal, or look for signs of DC voltage. Ceiling fans make a unique sound when you get a square wave on the power A/C. Doesn't make the fan spin faster, but you hear a slight hum when the square wave comes through... I know this after finding that my power company was not doing the best job cleaning up noisy A/C. Somehow one of their capacitors would generate random noise, It drove me crazy for months! I still had 60hz, but is was similar to a square wave at times...


Joe

 

[teg33]

Thanks Joe, I thought about that and did check it with an o-scope. It wasn't a perfect sine wave but wasn't too bad. When the lights were flickering and I viewed about 35 cycles on the scope, it did appear there was some low frequency (16Hz) amplitude modulation riding on the waveform but nothing really extreme.

Just wondering if anyone else has seen flickering lights with a PTO generator and what they did to resolve it?

 

[KYMike]

Don't know if this has anything to do with your problem, but I noticed some flickering if the PTO shaft is not straight in line horizontally & vertically. Universal joints are not constant velocity joints, so if they turn an angle (over 10-15%), there are vacillations in the RPM as the knuckle joints compensate. I needed to adjust the height of my unit on the trailer so it was at the same elevation as the PTO spline shaft.

 

[DAP]

I just purchased a PTO generator also. Gets here tommorrow in fact. The numbers are NOT matching up for you if I have the specs right. This assumes your Tiger generator is model PTO10 ....

I don't believe you are marginal at all. No, in fact, I think that your machine is clearly underpowerd to run a 10k watt generator. I believe that is why your power stream is inconsistent.

If your Tiger is model PTO10 it requires a MINIMUM 20hp at the PTO (not net HP). The B2410 is only 18hp and I suspect that your B2400 is at best equal to that. Correct me if I'm wrong. And yes, those 2 hp will make a difference, trust me. Further, running something like a generator at MINIMUMS is an invitation to lack luster performance.

Hopefully, I've got my assumptions wrong and/or you can return the generator.

Better still, buy a bigger Kubota! Sorry. I know it's not funny.

Hope it works out for ya somehow.

 

[teg33]

Thanks for the shaft alignment tip, I'll be sure to check that.

 

[john_bud]

</font><font color="blue" class="small">( Better still, buy a bigger Kubota!)</font>

I like the way you think! /forums/images/graemlins/grin.gif

jb

 

[teg33]

Doug, the B2400 is 18 PTO HP. The way it has been explained to me by various dealers, and seems to make sense, is that you need approximately 20HP to get the full rated current from a 10kW generator. However, if your load is less than 10kW then a smaller tractor will work just fine. In fact, some of the advice was to buy a bit bigger generator in order to improve the surge performance.

There is absolutely no indication that the tractor is working hard or loading down, even with 7kW of load. Also, as mentioned all spec readings (frequency, voltage, THD) are right on the money. I haven't seen anything to indicate there is a HP sizing issue. Would there be some other test you would recommend?