Hydraulic Pump motor rotation?

[tortuga]

Anyone have any tips on checking rotation on a Hydraulic Pump motor ?
Will it damage the motor/hydraulics if it briefly runs in reverse?
I am not sure there is anything I can see to give me a visual on rotation.
Its in a old press that got moved, not allot of info on it.
Its a 3 HP 1200 RPM
Thanks in advance

 

[drcampbell]

If it's a rotary style, it's almost certainly bidirectional.
If the pump is full of oil, you can run it in reverse briefly without harm.
While it won't harm the pump, it might suck the oil out of the system and overflow or burst the fluid reservoir if left turning in reverse for more than a moment. (don't ask me how I know this)

If it's a piston style with intake & discharge valves, it will probably run just as well in either direction.

 

[tortuga]

If it's a rotary style, it's almost certainly bidirectional.
If the pump is full of oil, you can run it in reverse briefly without harm.
While it won't harm the pump, it might suck the oil out of the system and overflow or burst the fluid reservoir if left turning in reverse for more than a moment. (don't ask me how I know this)

If it's a piston style with intake & discharge valves, it will probably run just as well in either direction.

Thanks for the reply Dan, Ill have to do some research and see what kind it is.

 

[GeorgeB]

Anyone have any tips on checking rotation on a Hydraulic Pump motor ?
Will it damage the motor/hydraulics if it briefly runs in reverse?
I am not sure there is anything I can see to give me a visual on rotation.
Its in a old press that got moved, not allot of info on it.
Its a 3 HP 1200 RPM
Thanks in advance

99% of the time, we view either the coupling or the fan.

Briefly ... 1 or 2 seconds for axial piston, ok. 10 or 20 seconds for external gear or vane, ok

For warm fuzzies, I'll normally have the millwrights pour some oil into the outlet port after an extended outage or move.

There are rotation meters that can determine which direction it will turn with motor and power leads connected to the meter; these are required on some submerged pump systems as there is no method to view. I've seen them used, but have no recollection of models or manufacturers.

 

[tortuga]

Thank you for the info George
Time to get some fresh batteries for my rotation meter,
If I had to guess I guess its 'external gear or vane'.

Its an old PHI manufacturing press, made in '78
Has heated plattens for molding shapes in I think plastic, fiber matt or rubber.

 

[hillbilly1]

Usually there is an arrow on the back fan housing on the motor. I know with cardboard balers, the ram will not raise if the rotation is backwards.

 

[paulengr]

Motors that have been run previously have a residual magnetism that can be detected by some rotation meters such as one from Amprobe. So you hook up the motor leads and it tells you rotation. Then hook up the line leads (leave disconnected) and briefly turn on power to check rotation. Then knowing the direction both ways you can wire it up without having to check further.