4.5kva diesel generator frequency problem

[jhall364g]

Hi, I have a 4.5kva diesel generator that powers my home in Spain, generally without any problems.

However, if I run the washing mashine I have to load the generator by switching on other electrical items such as a 2kw electric heater, otherwise the washing machine either fails to switch on, or won't spin, or just sits looking sulky at me.

I've been told that it could be because the generator isn't producing exactly 50hz, but all other electrical devices work ok - fridge, tv, computers, dvd, etc.

Anyone come across this problem before?
Cheers.

 

[itsmoked]

Are you sure you are not having some automatic standby situation? I had a 5kW generator that put out nothing usable until at least 100W were demanded then it would automatically speed up and enable the voltage regulator.

Do you have 1-200watts of other loads on when you go to run the washer?

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[Warpspeed]

I have encountered problems with SCRs and triacs when operating from lightly loaded standby generators. Apparently, suddenly switching from no load to significant load can distort the waveform and cause all manner of triggering problems.

Modern washing machines often use microprocessors and fairly sophisticated motor control techniques. There may be some unhappy circumstances that cannot be resolved without placing a steadying load on the generator. Extreme sudden swings of power factor may a problem too.

The speed/voltage regulator in your generator may not be entirely blameless either.

Perhaps the easiest way to solve all this grief would be to hook up a 2Kw radiator bar permanently to the washing machine. Not a very elegant solution unfortunately, but one that should work.

 

[itsmoked]

Or hook up an electric water heater to feed the washer. Set it so it heats to a few degrees higher than your existing water heater or heats cold water feeding your existing water heater.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[Warpspeed]

Another application where I have seen standby generators go absolutely frantic is when driving a ferroresonant transformer. As the line voltage drops the load current increases, the generator's voltage regulator gets very confused by seeing a negative resistance load, and can cycle. With any small frequency deviation either side of the transformer design frequency, the power factor usually goes absolutely extreme.

Some types of non linear load are just not generator friendly at all.