Time, what is time? or how does your tractor count hours?

[ch1ch2]

I went back and re-read the original post. I can't see what I am missing.
Is he not saying to the quote that it measures PTO speed not engine RPM?

 

[DavesTractor]

ch1ch2, tractors have a rated PTO speed, many of them are around 2400 rpm plus/minus a few hundred, where that speed gives you the output of 540 rpm. If you run a tractor at an engine speed that is equivalent to the PTO rated speed (even if the PTO is not engaged), the meter puts on an hour per hour. If you idle the tractor around at 1200 rpm, it will take two hours to put an "hour" on the clock. Construction equipment and other items that generally run at a pretty constant speed usually use a Hobbs type meter. If the key is on, it runs an hour for an hour, regardless of RPM. The better systems require oil pressure to complete the circuit, so that if you forget and leave the key on (but the unit not running) it will not spin the meter.

I bet you know all of this already, it is just a matter of the words we use to explain what we mean.

 

[ch1ch2]

Thanks that makes sense, and is worded so that even I can understand. Actually I was unaware of any hour meter other than Hobbs type. I guess I never paid any attention to it. When I started reading it it made sense to have hours based on engine rpm.

 

[willt1981]

I went back and re-read the original post. I can't see what I am missing.
Is he not saying to the quote that it measures PTO speed not engine RPM?

The original post posed a simple question - are all hour meters the same?

Some measure hours based on "rated speed", meaning the time the tractor runs the PTO at 540 PRM. On my tractor (NH TN60A) this is 2200 RPM. Idle speed is 600 RPM. My tractor measures an hour base on an hour of run time. So, if I idle for an hour or run at rated speed for an hour the hour meter runs the same. Other tractors measure this differently. An hour at rated speed is an hour. Anything else is measured at less time. So if my tractor idled for an hour with one of these meters the hour meter would actually read 0.27 hours.

Another point of the original post was the question of how one can compare tractor wear if different brands measure wear differently. I use my tractor a lot in the winter for pulling firewood, logging, and feeding cattle. I start it up in the morning around 8:00, let it run all day (even during lunch because we are often below 20 degrees during the winter days) and shut it off at 5:00. That's nine hours on my hour meter. Let's say I average 800 RPM during that time (a lot of idle time while pulling cables and cutting trees and eating lunch). On a rated speed hour meter my hours would read 0.36 of what they do now. So my 4600 hour machine would actually read 1656 hours.

In my opinion the NH isn't keeping an accurate track of overall wear but of engine run time. But, when it comes to trade ins, no one seems to care about the finer points of hour meters. Thanks to the original poster for drawing a little attention to this issue.

 

[ovrszd]

As has been said before in this thread,,,, if the tach is cable driven it is geared to be accurate at PTO speed, which is where older tractors were expected to spend most of their time. If the tach is electronic, it is ticking once power to the clock is activated. It stops ticking when power to the clock is deactivated. No magic in either system.

My '84 Ford is mechanical. My '12 Kubota is electric.

I can run my Ford most of an afternoon doing piddly, idling chores and it might chock up an hour. The Kubota doesn't care, turn on the key and it'll clock an hour 60 minutes later.

 

[DavesTractor]

The original post posed a simple question - are all hour meters the same?

Some measure hours based on "rated speed", meaning the time the tractor runs the PTO at 540 PRM. On my tractor (NH TN60A) this is 2200 RPM. Idle speed is 600 RPM. My tractor measures an hour base on an hour of run time. So, if I idle for an hour or run at rated speed for an hour the hour meter runs the same. Other tractors measure this differently. An hour at rated speed is an hour. Anything else is measured at less time. So if my tractor idled for an hour with one of these meters the hour meter would actually read 0.27 hours.

Another point of the original post was the question of how one can compare tractor wear if different brands measure wear differently. I use my tractor a lot in the winter for pulling firewood, logging, and feeding cattle. I start it up in the morning around 8:00, let it run all day (even during lunch because we are often below 20 degrees during the winter days) and shut it off at 5:00. That's nine hours on my hour meter. Let's say I average 800 RPM during that time (a lot of idle time while pulling cables and cutting trees and eating lunch). On a rated speed hour meter my hours would read 0.36 of what they do now. So my 4600 hour machine would actually read 1656 hours.

In my opinion the NH isn't keeping an accurate track of overall wear but of engine run time. But, when it comes to trade ins, no one seems to care about the finer points of hour meters. Thanks to the original poster for drawing a little attention to this issue.

I have seen very few compact or utility size tractors with a Hobbs type (not rpm dependent) meter. Seems odd that NH would do that on a TN60A. But you certainly know your tractor, so you must be right. Why would they do that? It would help them on a newer tractor warranty situation. Let's say you have 3 years or 2000 hours warranty. You might just hit 2000 hours when the typical guy is at 800. But I doubt it is really a conspiracy to take away 2/3rds of your warranty.

I think as tractors get larger, they probably spend more time doing real work. Take a 175HP tractor, it is generally pulling a plow, disc, shredder, harvester or something. And a farmer will size the implement as large as possible to minimize passes over the field. A Hobbs meter in that sort of application would probably be pretty indicative of work done.

I once heard that the real indicator of engine life is the amount of fuel burned. And I like that. If you are using it gently, you burn 1 gallon an hour, if you are at full rpm and full load, maybe 3 gallons/hour on a 60HP tractor. Total gallons burned over the life of a tractor would be great data to have.

Your point on trade-in value is well taken. Try to explain that to an uneducated buyer and he would surely think you are a crazy crook. "Well yeah, it says 4600, but it means 1656 hours. And I only drove it on Sunday, never when dusty and it's never been in the rain. Honest". Kind of funny to envision that scenario.

 

[DavesTractor]

As has been said before in this thread,,,, if the tach is cable driven it is geared to be accurate at PTO speed, which is where older tractors were expected to spend most of their time. If the tach is electronic, it is ticking once power to the clock is activated. It stops ticking when power to the clock is deactivated. No magic in either system.

My '84 Ford is mechanical. My '12 Kubota is electric.

I can run my Ford most of an afternoon doing piddly, idling chores and it might chock up an hour. The Kubota doesn't care, turn on the key and it'll clock an hour 60 minutes later.

To further add to this, many meters are electronic and still are rated at PTO rpm, as if they were the old cable style. They take the rpm off a signal on the alternator or a signal on some sort of electronic pickup on the flywheel or other rotating device. Since it is pulled from a rotating part, they can still behave like a cable driven unit.

 

[ovrszd]

To further add to this, many meters are electronic and still are rated at PTO rpm, as if they were the old cable style. They take the rpm off a signal on the alternator or a signal on some sort of electronic pickup on the flywheel or other rotating device. Since it is pulled from a rotating part, they can still behave like a cable driven unit.

Good point. I didn't realize any were doing that. But it makes sense and would be easy to do in the computer world of modern tractors.

 

[sdef]

My 2001 Kioti DK 35 hours is based on engine speed. Near PTO speed for 1 hour= 1 hour.

I have often wondered about this also as my 2013 DK45 HST must register similar. Otherwise the hours do not match with actually engine running time.

 

[Threepoint]

I have often wondered about this also as my 2013 DK45 HST must register similar. Otherwise the hours do not match with actually engine running time.

In marketing for the DK series, Kioti says "The electronic hour meter accurately records the real working hours of the tractor." To me, that means the hour meter records based on an algorithm linked to engine speed, weighted to record faster at rated PTO speed. I doubt it is a straight linear relationship, but don't know.

I have a 2014 Kioti NX4510HSTcab, but haven't found a similar statement about the NX series in marketing or the manual. So I recently I started a thread asking about that: www.tractorbynet.com/forums/kioti-owning-operating/345939-nx-series-engine-hour-meters.html This is more a curiosity for me than anything else.