What's the failure mode for electric clutches?

[BarnyardEngineering]

I've got an older Ferris ProCut Z that's losing a lot of blade speed in heavy grass.

There's no belt squealing or burning rubber so it seems like the cutch is slipping. Do electric mower clutches slip?

 

[DoubleO7]

I've got an older Ferris ProCut Z that's losing a lot of blade speed in heavy grass.

There's no belt squealing or burning rubber so it seems like the cutch is slipping. Do electric mower clutches slip?

Maybe not getting full voltage?
Maybe corroded or broken wires or terminals?
Bads ground?
Maybe rusty surfaces that interact when energised?

Kinda like electric drum brakes on a trailer?

 

[J Hamilton]

I've got an older Ferris ProCut Z that's losing a lot of blade speed in heavy grass.

There's no belt squealing or burning rubber so it seems like the cutch is slipping. Do electric mower clutches slip?

Some of them can be adjusted. I believe there should be a .010 air gap. If it is adjustable, there would be 3 or 4 bolts on the outside with a spring under them, like pictured

 

[T.R.K.]

check the ohms in your clutch coil. On most of them you should get 2.5 to about 5 ohms. I don't know about Ferris. Some Bobcat clutches are perfectly good at 2 ohms resistance.
also, with the clutch 'off' check the clearance between the drive plate and the driven plate. They usually start having problems at .040 or above.
(But usually it is more of a "won't come on." or "runs a while and cuts off when hot." complaint.)
Another thing to check: the V-groove in the pulley. It should be a 'V' with flat straight sides. any dips or 'steps' in there means the pulley itself is worn and is probably slipping, whether it is making noise or smoke or not. Also check your spindle pulleys for the same profile.

 

[oldsarge]

check the ohms in your clutch coil. On most of them you should get 2.5 to about 5 ohms. I don't know about Ferris. Some Bobcat clutches are perfectly good at 2 ohms resistance.
also, with the clutch 'off' check the clearance between the drive plate and the driven plate. They usually start having problems at .040 or above.
(But usually it is more of a "won't come on." or "runs a while and cuts off when hot." complaint.)
Another thing to check: the V-groove in the pulley. It should be a 'V' with flat straight sides. any dips or 'steps' in there means the pulley itself is worn and is probably slipping, whether it is making noise or smoke or not. Also check your spindle pulleys for the same profile.

T R K You about covered it. Goodonya !!!

 

[wore out]

check the ohms in your clutch coil. On most of them you should get 2.5 to about 5 ohms. I don't know about Ferris. Some Bobcat clutches are perfectly good at 2 ohms resistance.
also, with the clutch 'off' check the clearance between the drive plate and the driven plate. They usually start having problems at .040 or above.
(But usually it is more of a "won't come on." or "runs a while and cuts off when hot." complaint.)
Another thing to check: the V-groove in the pulley. It should be a 'V' with flat straight sides. any dips or 'steps' in there means the pulley itself is worn and is probably slipping, whether it is making noise or smoke or not. Also check your spindle pulleys for the same profile.

Doesn't hurt to measure operating voltage & current at the clutch coil, maybe in the 4 - 5 Amp range? What have you seen as typical, T.R.K.?

 

[T.R.K.]

Of course you want the system voltage to be over 13v. (less than that and there is nothing charging the battery.) You want to be close to that at the clutch, but there will be some resistance losses. I don't know what the minimum shoud be, but I would probably start worrying if I see about 11 volts at the clutch if it is having problems.
So if you want to know the current, usning Ohm's law, v=I divided by R, you get about 2.5 to 5 amps., depending if you use 2.5 ohms or 5 ohms in the equation. (Some Husqvarna clutches are fused with a 7.5 amps fuse.)

 

[Farmalldude45]

Of course you want the system voltage to be over 13v. (less than that and there is nothing charging the battery.) You want to be close to that at the clutch, but there will be some resistance losses. I don't know what the minimum shoud be, but I would probably start worrying if I see about 11 volts at the clutch if it is having problems.
So if you want to know the current, usning Ohm's law, v=I divided by R, you get about 2.5 to 5 amps., depending if you use 2.5 ohms or 5 ohms in the equation. (Some Husqvarna clutches are fused with a 7.5 amps fuse.)

Pretty sure Ohm's law is V = I times R.