The EO-3 pump package includes a 115 or 230 VAC motor direct coupled to a gear pump and mounted on a 3.6 liter (7.6 pint) plastic reservoir. Each is equipped with a low level switch and rated for service up to 24 bar (350 psi) . Timer equipped models include a built in pressure switch. On/off cycles on remote control models are programmed by a remote timer or from a machine's PLC where available.

When electrical power is applied to the pump motor, lubricant flow pressurizes the system mainlines causing the piston distributors to dispense a measured volume of lubricant to the bearing points.

Making of the pressure switch contacts (pressure switch equipped models) or expiration of the on time causes power to be shut off from the motor. This stops flow and permits the internal vent valve to release mainline pressure which allows the piston distributors to re-prime in preparation for the next lube cycle.