Just an update.

The lift limit switch was defective. It's why it would not go into full speed.

The unit operates normal. Thanks for all the help!

If I remember correctly, sevcon units will run, very slowly, in a default setting mode. Had this happen a few times. Sometimes they just reset themselves. IIRC it's blamed on a capacitor (for the memory) discharging when it shouldn't.

No idea about your settings though. Not much online for that machine.

like edward says there could be a limit switch on the boom not working correctly or a wiring issue in that circuit. Also the limit switch on the swing limit, usually when swing is more than 10deg past center it will slow down the speed.
The boom has to be straight in center of travel line, fully lowered and retracted completely to get full speeds.

you also want to double check the controller in the basket and make sure the pot is giving its full range to the controller. Sometimes these pots go bad or the linkage to it gets loose and allows the gear on the pot to slip.

as for the settings the controller uses it would be nice to know the drive controller this unit uses. If your looking to find one at grove you probably wont since the manlift division no longer exists. You'll have to find a dealership that used to carry grove and might still sell parts that MAY have a manual for it, that's a longshot though.

one more thing
check the switches on the basket control panel and see if it has a switch for torque speeds used for driving on inclines. one setting allows for fast speeds on level ground and the other setting gives it more drive torque but is a bit slower.

a few things to check for while scratchin yer head ;o)

these things usually have a switch that prevents full speed travel if the boom is not all the way retracted and all the way down. it may also have a speed reduction circuit if the turret is not near to 'straight ahead'. have you checked for these switches?

Hi,

We finally got approval for the repairs. The controller was definitely damaged. The root of the problem was a shorted drive motor. The motor was sent out for repairs and brought back after the repairs.

After installation of the drive motor, the unit has no speed. It travels about 2 mph in forward and reverse without any error codes.
Now, the problem is that, if I remove the wiring from the Tach sensor and reverse it, the unit will speed up, but only travels 3 feet before it cuts out and codes 10, Speed encoder fault.
I have a handset, but not the specs.
I placed the wiring back on the tach, but it continues to creep without any codes. Are the tach wires polarity?
Is there any possible way I can obtain the setting for this controller. The controller is a MOS90D.
Any help will be appreciated.....

Thank you for all the information. At this time I am waiting for my customer to decide on proceeding further with the troubleshooting and diagnostic.
Once I get my hands back on it, I will post.

I did previously checked the contactors for welded tips or a fault in the coil. The contactors are working correctly.

actually it depends on which controller is in this unit
there are traction based controllers and pump based controllers
generally in electric sissorlifts and boomlifts the controller serves a dual role as a traction controller and hydraulic controller. Most of the ones i've seen are the sevcon MOS90 series.

Now looking at the trouble code chart there are 2 possibliities here
Traction controllers:
3 flashes
Bypass contactor welded - recycle through neutral to clear.
Contactor coil short circuit - recycle the key switch to clear.

Pump controllers:
3 flashes
Short circuit across Mosfets, or motor open circuit.

I would check the bypass contactor for welded tips
this may explain why replacing the controller did not fix the problem.

Also remember when replacing a controller you may be required to set it up with the manufacturer's settings, sevcon does not custom set their controllers to anything other than the base settings any controller comes with. Furthermore you WILL need the handset to change any settings in the controller. Yes it might run "as is" but it will not be setup correctly and could damage the controller if you run it that way. As for getting any setup information from grove? good luck with that, grove manlift division went out of business years ago so information is hard to come by these days unless someone(that already has it) feels generous about it. I myself dont have any specific manuals related to this machine so i cant help you there. sorry.

The three flashes indicate a MOSFET short circuit. If the controller has already been replaced I would check your power cables and motor for excess corrosion or shorts to frame.