What are hours on a tractor

[rasorbackq]

The hour meter indicates hours of operation.
Is one hour idling the same as 1 one at 3000RPM?
Or is there a standard of 1 hour = 1 hour at pto speed??

 

[Samuellm]

Or is there a standard of 1 hour = 1 hour at pto speed


This is how every mechanical one I have seen works. I have seen digital ones that are a counter that starts when the key is on.

 

[streamin]

that's a good question because I always assumed it was an hour for an hour no matter what the speed was. now I'm curious since it was brought up

 

[rasorbackq]

The reason I asked is I just bought a Tractor mounted log splitter and I had to weigh the tractor running hrs over a stand along splitter.

Seems some times the Hrs are slow to add up when driving the tractor or working .
Lets see what others say.

 

[JerryK]

Some 'hour meters' work straight off the 12v, and one hour is one hour... just like a clock. Most tractors weight the time at full RPM different than idle. A lot of these use a pulse coming off the alternator to help decide what to accumulate as an hour. 'Usually', an hour at full rated PTO RPM=one real life hour....

 

[Gary Fowler]

Some 'hour meters' work straight off the 12v, and one hour is one hour... just like a clock. Most tractors weight the time at full RPM different than idle. A lot of these use a pulse coming off the alternator to help decide what to accumulate as an hour. 'Usually', an hour at full rated PTO RPM=one real life hour....

Used to be, all hours were clocked at PTO speed, less than RPM @PTO speed meant the hours rolled over slower. Now some of the lower end tractors just use an hour meter that runs when the key is turned on. This is OK I guess for lawnmowers where the engine runs full throttle almost all of the time but for a tractor, one really needs to monitor the engine time based on a RPM speed so we can properly assess the wear on the engine and especially the oil.

The only real way to tell is to turn on the key and see if the hour meter runs or it remains the same. 1/10 hour on the meter would be 6 minutes so it wont take long to see if the clock registers real time or engine PTO speed time.

 

[CCWKen]

For mechanical tachometers, it used to be hours at PTO speed and called a "Proof Meter". PTO speed was usually much less (rpm) than say draw bar or pulley speed but the tachometer was adjusted to show hours at PTO speed. It seems to me that the newer the tractor, the closer PTO speed gets to rated rpm. That wasn't the case in earlier tractors that had about a 500rpm difference between PTO speed and rated speed. (Or about 75%) It was meant to keep PTO speed closer to the power band of the engine. At higher speeds, the meter ran faster and at lower speeds it ran slower.

For electronic meters, it can be closer to actual clock time. It could be when the ignition is on or when the engine is running. It depends on the type of sensor/timer used. Many use a tachometer pulse from the alternator so the timer runs only when the engine is running. More sophisticated timers will use engine speed divided by engine speed at the PTO rate.

So.... In most cases, one hour on the meter is one hour of work at the PTO rated speed of the engine.

 

[CCWKen]

Forgot to mention: Your owners manual should describe how the hours are accumulated.

 

[Leejohn]

What about when the pto is not being used?

 

[dieselcrawler]

"At rated 540 pto rpm" not only if the pto is engaged. Tach doesn't care ifor pto is running, it measures motor revolution, on a sliding scale, based on the rpm it takes to turn the pto IF it were ingaged.