[Ron]

If you remove the belt driving the generator water pump pulley your generator will get no coolant circulation so it will not take long to reach the high temp limits.

If you have the balls and reflexes to do that just make sure you have an accurate, reliable coolant temp gauge for the generator so if it does not shut down you can do it manually based on the gauge reading.

If you maintain the proper coolant level, have good quality hoses and clamps, and always have a good belt correctly tensioned you should never have to rely on the switch.

[Jonathan]

Jon, maybe he means “high water sensor” and not “switch” ?

Just an observation from KC Missouri where it snowed last night.

[Archived]

Whether it is high water or high temp it is still a switch when the limit is reached, presumably opening the circuit to shut down the generator.

If that switch reliability is a concern, the oil pressure sensor (switch) should be an equal concern and should be tested as well.

[Kirby]

I would be reluctant to run a gasoline or diesel engine without the water pump running. I’d be concerned that without the coolant circulating in the engine there would be hot spots (particularly around the combustion chambers) that could result in really high temps and pressures before the coolant temp gauge would show the excessive temperatures. High enough to damage the engine.

I would rather disable the fan on the radiator, allow the water pump to move the coolant throughout the system, and monitor the coolant temp gauge. Without the fan running and limited air circulating across the radiator the temp should rise quickly.

Either way, I would be very reluctant to use any method of over-temping the engine to test the high temp switch There has to be another method of checking it.

[Art]

On my 94 CC if I ran the gen with the bay door open the temps would jump way up. With the door closed it would run the proper temp, I figured it had to do with how the air was drawn by the fan through the radiator and exhausted out of the bottom of the bay.

[Tim]

I was tongue in cheek when I said to disable the water pump because to be consistent we need to check all limit switches or sensors, not only on the generator but the engine also.

If we lack confidence in any of the devices intended to shut down an engine or generator we have a lot of work ahead of us because we not only have to find the limits, we have to test the devices at the limits. To use the high temp generator as an example we have to create a means of heating a liquid to 235 degrees (maybe oil?), have a calibrated gauge to be sure we are in fact at the right temp, and have the device connected to something to signal when the circuit opens or closes.