Smokin' H bridge

[Ga Mtn Man]

The control box has a ground wire that runs directly to the battery.  I do not believe that the bottom rail/grounding block had anything to do with your H-bridge failure (unless your mill is wired differently than a standard LT40HD).

[petefrom bearswamp]

Well I followed the steps to the letter.
Wouldn't work so called WM Hannibal.
Actually called several times.
After trying several things the WM tech said I must have gotten a bad part.
Now am waiting again for a new H bridge.
Lost 4 days sawing so far.
Also paid my man for about 6 hrs non productive time so far, but Oh well.
Such is the lot of the sawyer.
I think yellow hammer may be right in reversing before a complete stop but this of course will effect production.
Pete

[Brucer]

Add up all the production you'd lose by not stopping your carriage before shifting back into forward. Compare that to how much production you've lost so far :(.

And just for you hydraulics-only types, you can also blow out the seal on a hydraulic motor by reversing it while it's still traveling in the other direction.

[ladylake]

 After over  9000 hours  with no feed problems I'd say hydraulic feed works good and I'm not easy on it.  I did have to put a couple of $7 bushings in the front idler and a $50 part in the speed control, neither shut the mill down. Steve

[petefrom bearswamp]

I Like the modern stuff but sometimes think it is too sophisticated and obviously is prone to electronic failure.
I only have 650 hours on my 2008 mill.
Have maintained it judiciously except for the ground which i didnt know about or overlooked so far.
Have lost 4 days sawing so far and am glad I do not have to rely on the mill for my livelihood.
steve i dont understand how the forward and reverse issue talked about earlier has a bearing on my problem.
Brucer so far I have lost the 4 days and hadnt had a problem previously.
Maybe sparks will join in and explain it to me.
 

[stavebuyer]

When my last H-bridge went out it was due to a bad bearing on the drive sprocket. That bearing fried my drive motor and the newly replaced motor overloaded the H-bridge. Be sure to check that your head travels freely and that your drive motor is good. H-bridge can be the symptom and not the problem.

[petefrom bearswamp]

Up and running one week later.
Yippee
Pete

[Magicman]

Hopefully you have also conquered the "whys".  You certainly do not need a repeat. 

[petefrom bearswamp]

Thanks Lynn
Everything went well today finished an order of 2x10x12 Hemlock and 2x2x 12 stake stock.
Glad i have a young 53 yr old to help me.
Someday I'm going to weigh one of those green hemlock planks, but they must weight 70 80 pound each for 2x10x12.
Had one hiccup when the head wouldnt go up but it seemed to correct itself.