HP and a/c

[jimg]

I know Ive seen this somewhere in TBN but I cant find it. So Ill ask again but only in regard to NH tractors....how much hp should I expect a/c to consume in a new tractor? Does it depend on model? How about older models (mid 80s to 90s models)? I would expect theyd be less efficient but by how much (assuming the a/c unit is in good working order)? Just so I understand this correctly...if Im consuming x hp for the a/c thats x hp less Ill have at the PTO? In other words PTO hp figures dont include other power drains (like a/c).

 

[JerryG]

It was about a years ago, in the JD forum.

 

[jimg]

Im not finding it...Ive looked in both forums for all of the likely variations/combinations of air conditioning and horsepower (including abbreviations). Do you recall if the title is about this topic in particular or did it morph into that as the discussion progessed?

 

[Robert_in_NY]

Richard (cowboydoc) was the main one discussing it from his own experiences. Toss him a PM and fire the questions at him or go to the general board and ask

 

[KenPauling]

With the newer TN series of tractors, it isn't an issue. I have a 2 year old TN65D with cab and it seems the a/c unit uses so little power, it isn't an issue. I've pulled a 3 bottom plow while using the a/c cycling it from off to on and no noticible decrease in power, ground speed or rpm. I've pulled a 13 foot disc and a 6 foot mower with the same results- NOTHING! It makes no difference to the newer tractors. Ken

 

[KenPauling]

With the newer TN series of tractors, it isn't an issue. I have a 2 year old TN65D with cab and it seems the a/c unit uses so little power, it isn't an issue. I've pulled a 3 bottom plow while using the a/c cycling it from off to on and no noticible decrease in power, ground speed or rpm. I've pulled a 13 foot disc and a 6 foot mower with the same results- NOTHING! It makes no difference to the newer tractors. Ken

 

[AndyMA]

I agree with Ken. On my TN75D, switching the a/c on and off has no noticable effect on power. I suspect that the a/c is using a hp or 2, but that these engines have such significient torque reserve that they just producte the small amout of extra power required and you don't notice it.

Andy

 

[AndyMA]

I agree with Ken. On my TN75D, switching the a/c on and off has no noticable effect on power. I suspect that the a/c is using a hp or 2, but that these engines have such significient torque reserve that they just producte the small amout of extra power required and you don't notice it.

Andy

 

[jimg]

I could believe that new tractors would be very efficient. However, a new tractor isn't in my future as the cost is just too high. If I can find a good used TL or TS that would be nice but I think Ill wind up w/ something a bit older. My impression is that older machines won't be so efficent.

 

[jimg]

I could believe that new tractors would be very efficient. However, a new tractor isn't in my future as the cost is just too high. If I can find a good used TL or TS that would be nice but I think Ill wind up w/ something a bit older. My impression is that older machines won't be so efficent.

 

[Soundguy]

</font><font color="blue" class="small">( and a 6 foot mower with the same results- NOTHING! It makes no difference to the newer tractors. Ken )</font>

Please... a 6' mower on that beast of a tractor.. Of course the ac doesn't make a difference.. you have no load ont he tractor. My 1975 ford 5000 with 67 pto hp pulls a 10' mower... that's a load.

I'ts likely you could drain off 20-30 hp for a pto device, plus lots of other parasytical hp requirements and STILL not notice a drop in enggine rpm.. that's what your governor is for.

You set your hand throttle.. that selects and rpm range, as you add load, your governor tries to maintain that rpm level. Untill you get to a point where more throttle does not produce more rpm ( lugging the engine ) you have 'reserve' hp available.

It's a simple supply and demand issue.. the engine is the supply.. the loads are the demand.. the commodity is HP. If you have 65 pto hp available, and have implement, and drivetrain loads that take 40 hp.. you have 25 hp reserve left over.. kick out? 2-4 hp for the ac.. and you still have reserve hp. etc...

Small hp drains won't be an issue unless you are running at or near max load...

My 12.5 kw genny .. when I have it hooke dto my NH 7610s.. nothing changes on the tractor tach whether I'm using a 120w lamp.. or a 10a skill saw.... since I may only be using up to 24 pto hp, and I have ? 66 or so left over.. its not a load over capacity issue...

Soundguy

 

[Soundguy]

</font><font color="blue" class="small">( and a 6 foot mower with the same results- NOTHING! It makes no difference to the newer tractors. Ken )</font>

Please... a 6' mower on that beast of a tractor.. Of course the ac doesn't make a difference.. you have no load ont he tractor. My 1975 ford 5000 with 67 pto hp pulls a 10' mower... that's a load.

I'ts likely you could drain off 20-30 hp for a pto device, plus lots of other parasytical hp requirements and STILL not notice a drop in enggine rpm.. that's what your governor is for.

You set your hand throttle.. that selects and rpm range, as you add load, your governor tries to maintain that rpm level. Untill you get to a point where more throttle does not produce more rpm ( lugging the engine ) you have 'reserve' hp available.

It's a simple supply and demand issue.. the engine is the supply.. the loads are the demand.. the commodity is HP. If you have 65 pto hp available, and have implement, and drivetrain loads that take 40 hp.. you have 25 hp reserve left over.. kick out? 2-4 hp for the ac.. and you still have reserve hp. etc...

Small hp drains won't be an issue unless you are running at or near max load...

My 12.5 kw genny .. when I have it hooke dto my NH 7610s.. nothing changes on the tractor tach whether I'm using a 120w lamp.. or a 10a skill saw.... since I may only be using up to 24 pto hp, and I have ? 66 or so left over.. its not a load over capacity issue...

Soundguy