Generator at low loads

[EricElec]

I am proposing using a 14kw generator for prime power that will be lightly loaded at ~4kw during summer, but winter time would be ~12kw.

Will under loading during summer / low load conditions cause problems with pf and wet stacking? Or do these problems only occur with larger >50kw gensets?

 

[itsmoked]

Lots of variables. How many hours a day are you talking about? All day, every day?

Keith Cress
kcress -

http://www.flaminsystems.com

 

[EricElec]

Generator running all day 24/7

 

[waross]

This reminds me of a brand new 14 kW set with the muffler mounted above the engine.
The muffler had a crimped but not welded seam on the bottom side.
It ran for an hour and the set was covered with black sooty oil leaking from the muffler seam.
Wet stacking can occur with any diesel.
I was able to cure more than one new slobbering diesel by running for a few days with a load bank.
Once the rings seat in there is generally no more problem.
It is a good idea to observe the set for the first few hours of running under light load.
If there is no oil in the exhaust and the oil level in the sump does not go down in the first few hours, you are good to go.
Otherwise find a load bank.
Red Neck load bank, but it works well.
Caution. This was done in Central America where there were no safety rules or regulations.
One 50 Gallon plastic barrel.
Two automotive leaf springs from the scrap yard.
A little longer than the barrel is high if possible. If not, improvise. It's not a piano.
Connect a hot lead from the generator to each leaf spring.
Arrange the springs inside the barrel, on opposite sides.
Fill the barrel with water.
Put a clamp-on Ammeter on one of the leads.
Start the generator and energize the leaf springs.
Start adding salt to the water, while watching the ammeter.
Load up to about 60% to 75% of the set Ampere rating.
The water will boil.
Add make-up water several time a day.
Use barricades or other methods for protection of personal.
Local safety rules apply.
You are responsible for finding a way to meet local safety rules and regulations.
You are responsible for any accidents or damage or injury.
As well as live exposed parts you will have 50 gallons of boiling water.
User beware.
Note for winter use: In cold weather the set may use as much or more fuel keeping itself warm as it uses to generate electricity.
I was running a house on a 6 kW set in minus 20F to minus 30F.
I put a solid baffle about 2 inches in front of the radiator and the fuel consumption dropped about 30%.
Winter heating.
Don't use electric heat. It is probably twice as effective to burn the diesel fuel in a heater than to generate electricity to use for heat.
A thermostatic rad shutter is a good idea for cold weather running.
Consider mounting a heat exchanger in your heating ducts and diverting coolant from the engine in the winter.
Do not take so much heat that the coolant returning to the engine is too cool.
Not enough heat? Now add some electric heat. For every BTU of electric heat you will get an additional BTU from a well designed heat extraction system.



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

 

[crshears]

What Bill said.

Hmmm...

OP didn't specify it was a Diesel engine driven set; is it?

CR

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

 

[itsmoked]

Don't use electric heat. It is probably twice as effective to burn the diesel fuel in a heater than to generate electricity to use for heat.

Not true - if you run the generator in your living room.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[itsmoked]

Oh oh oh!! This reminds me. Got a call today.

A place has a generator running 24-7 to keep wax hot. The wax pump is 1-1/2HP and the associated wax heater is NGas fueled. 12 hours a day they run the generator only for the wax pump/heater. The generator is 400kVA... A 520HP diesel running a 1-1/2HP motor.

They want to reduce the $8k/month those 12hours/day are costing them.
I had them get a Honda EU7000i and loaned them a 5HP VFD. Even that expensive $4k EU7000 has a 2 week payback!

Keith Cress
kcress -

http://www.flaminsystems.com

 

[waross]

Reminds me of the time I connected a small transformer directly to the terminals of a 350 KW diesel set to run a small drill motor.
It was a shut-down of a small generating station for work on the main panel.
We couldn't close the generator breaker while working on the panel.
CR; Yes, I assumed, based on the query about wet stacking. My bad.

Not true - if you run the generator in your living room.

14 KW? Do-able, just not in front of the TV.
Remember to order the Quiet option. grin

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

 

[EricElec]

it's a diesel generator