A diesel generator question

[iwire]

The fact it is not corrected speaks volumes about the level of technian involved.

If we call in a generator tech we expect they can either fix the problem or at the least identify the problem.

 

[Besoeker]

415V.With it,it is only developing 22kW and not full load 24kW.Moreover,the specs demand overload capacity of 10% for one hour.So the gen set should be capable of supplying 26.40 kW for at least one hour.But it does not.Another identical gen set under identical conditions(lying idle for almost two years) installed in a different telephone exchange passed the test.But this one does not.

Can you describe the storage conditions? Wrapped and crated? Silica gel desiccant?
I think many engineers would consider it not a good thing to have the sets lie idle for so long.
We do a fair bit of work in the water industry in UK and most pumping stations have a back up generator. Bad news if people lose their water supply, you understand.
We neither supply nor maintain these but my understanding is that they are routinely run up about once a month for test purposes. There are oil and block heaters so that cold starts are avoided.
Some oils are hygroscopic and if you have humid storage conditions the moisture could have had deleterious effects on engine components.

Just a further thought that occurred to me while typing the above.
How long did you run the gen set before taking the readings? Did the engine get up to working temperature?
And another. Did you measure the generator terminal volts?

And just a small request. Could you please put a space after punctuation marks?
It's how it ought to be done but, much more importantly, it makes the text easier to read.

 

[T.M.Haja Sahib]

If you can see the throttle linkage, watch to see if the linkage is moving all the way, thus opening the throttle all the way as you lose power. If it is, you likely have an engine problem, if it's not, you likely have a controller problem.

This is intriguing.For normal operation of diesel engine,how the throttle linkage should move?
During initial starting of engine, the technician adjusted the speed to 1500 RPM by moving a screw on the throttle linkage.I did not notice the throttle linkage would move automatically depending on load on it.Does it?

 

[T.M.Haja Sahib]

Can you describe the storage conditions? Wrapped and crated? Silica gel desiccant?

The gen set is inside a sound proof canopy and so somewhat 'protected'.

How long did you run the gen set before taking the readings? Did the engine get up to working temperature?
And another. Did you measure the generator terminal volts?

Answers question wise:
1)Around half an hour. 2)Sorry, did not notice.3)Yes. 412V.

And just a small request. Could you please put a space after punctuation marks?
It's how it ought to be done but, much more importantly, it makes the text easier to read.

Sorry. Try to follow.

 

[Besoeker]

This is intriguing.For normal operation of diesel engine,how the throttle linkage should move?
During initial starting of engine, the technician adjusted the speed to 1500 RPM by moving a screw on the throttle linkage.I did not notice the throttle linkage would move automatically depending on load on it.Does it?

Yes. A speed governor is required to maintain set speed. Closed loop speed control.

 

[K8MHZ]

This is intriguing.For normal operation of diesel engine,how the throttle linkage should move?
During initial starting of engine, the technician adjusted the speed to 1500 RPM by moving a screw on the throttle linkage.I did not notice the throttle linkage would move automatically depending on load on it.Does it?

The engine speed should be controlled by a governor. The governor controls the throttle. With no load on the generator, it takes much less fuel to maintain 1500 rpm. As the load increases, the engine needs more fuel to maintain 1500 rpm so the governor moves the throttle linkage for more fuel. If the load is so great that the engine cannot power it, the governor would have the throttle wide open in an attempt to provide enough fuel to the engine.

So, indeed, the throttle linkage should move automatically depending on the load. That's just simple physics, really.

 

[Besoeker]

The gen set is inside a sound proof canopy and so somewhat 'protected'.

Canopy or enclosure?
Just a roof or walls too?
Were they unwrapped?

 

[Besoeker]

The engine speed should be controlled by a governor. The governor controls the throttle. With no load on the generator, it takes much less fuel to maintain 1500 rpm. As the load increases, the engine needs more fuel to maintain 1500 rpm so the governor moves the throttle linkage for more fuel. If the load is so great that the engine cannot power it, the governor would have the throttle wide open in an attempt to provide enough fuel to the engine.

So, indeed, the throttle linkage should move automatically depending on the load. That's just simple physics, really.

Cruise control is the automotive version.

 

[K8MHZ]

Cruise control is the automotive version.

Not really.

(I have been working on cruise controls since they first came out. I have rebuilt many transducers).

Cruise controls respond to a change in vehicle speed, not engine rpm. Unlike a governor, engine rpm can drop to an idle or red line as conditions require.

Thinking about it, the physical difference may be that cruise controls control horsepower (change engine speed as needed) and governors control torque (maintaining a constant engine speed by controlling crankshaft torque).

I used to be a certified mechanic. I worked on many Brit cars and have a love like no other for Lucas electrical systems. This was a while ago, but I used to work on Jags, MG's, and Triumphs that were collector items. Meaning, for the most part, they sat around collecting dust because they were too unreliable to drive on a daily basis.

:lol:

 

[iwire]

Cruise controls respond to a change in vehicle speed, not engine rpm. Unlike a governor, engine rpm can drop to an idle or red line as conditions require.

I am at a loss as to why you feel they are so different. :?


Basically the only difference is the placement and / or type of sensor providing the input to the controller.

In the end both systems control the flow of fuel or air into the engine in repose to conditions.

 

[K8MHZ]

To add,

Some heavy equipment will have both a governor and a cruise control.

The governor is used to control engine speed when using a PTO, for instance. The cruise is used to maintain vehicle speed while driving.

 

[K8MHZ]

I am at a loss as to why you feel they are so different. :?


Basically the only difference is the placement and / or type of sensor providing the input to the controller.

In the end both systems control the flow of fuel or air into the engine in repose to conditions.

I have worked on both. They are entirely different critters. Governors don't need sensors. They can operate centrifugally. They can be connected directly to the throttle via one single linkage.

Cruise controls take input from the drive line and adjust the throttle by either pneumatic or electric means. You won't see a cruise control that operates a throttle directly with a single linkage. The linkage or cable will be connected to an electric or a pneumatic transducer somewhere. That transducer will get its info by either electrical or mechanical means. Today we have sensors, but back in the 80's the transducer was connected to the speedometer cable.

Have I justified my position??

 

[Besoeker]

Not really.

(I have been working on cruise controls since they first came out. I have rebuilt many transducers).

Cruise controls respond to a change in vehicle speed, not engine rpm. Unlike a governor, engine rpm can drop to an idle or red line as conditions require.

The basic principle is the same. Closed loop speed control. The governor on a genny maintains shaft rotational speed. On a car, it maintains road speed.
The car I currently drive, like most in the UK, has a manual box. Thus, when I set the cruise control, it keeps both the engine RPM and the road speed constant.

I used to be a certified mechanic. I worked on many Brit cars and have a love like no other for Lucas electrical systems. This was a while ago, but I used to work on Jags, MG's, and Triumphs that were collector items. Meaning, for the most part, they sat around collecting dust because they were too unreliable to drive on a daily basis.:lol:

Actually, one of the nicest cars I had was a Triumph 2500TC. It had a a sweet six pot in-line 2500cc petrol engine and a four speed box with overdrive on the top two cogs. So, effectively, six forward ratios. Top slot gave me just a bit over 2,000 rpm at 70mph, the UK legal speed limit and reasonably decent fuel consumption. I did all the servicing myself - oil, filters, spark plugs, points, timing, brake pads....stuff.
It gave me 100,000 miles of serene motoring. As was still running sweet as a nut when I departed with it.
Next car was a dog. A German Ford, the top of the range, and the engine failed after about 9,000 miles.
After a couple of further bad foreign experiences I got the 12 pot jag in the avatar.
Then another 100,000 serene miles but with a bit of a kick from the 300bhp sweet revving Brown's Lane product.
But fuel prices here.......

Mods, please forgive my off topic response....

 

[dave__asdf]

Check the hose between the tank and the fuel pump. Older hoses at high flow can create enough suction to collapse and starve the engine. Also, i think a technician on site is your answer. If the first guy didnt get it another might if the additional few kw are that important.