Electro-hydraulic is simply an electric motor powering the hydraulic pump instead of the hydraulic pump being connected to an engine.
The motor only runs when there is a demand for hydraulic flow. Often times the motor will only run when pressurizing – like when an electric pallet jack is lifting a load. When the load is lowered the pressure is allowed to bleed off, not requiring the motor to run.
Other systems, like you might find on a dump trailer require the electric motor to run in both directions, known as power up/power down.
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