Daikin Hydraulic Unit EHU2507-40

• Turn the cap in the counterclockwise direction by hand and remove it.

• Air blow the filter section to blow off deposits and adhering material. Also remove dirt from inside the strainer’s cylinder.

• Fit the cap by turning in the clockwise direction by hand to the position where it stops.

WARNING! When using air blow, wear protective glasses to avoid getting deposits and dirt in your eyes.;

1. Set a drain oil receiver below the oil drainage port, open the oil drain plug (M12 × 20L), and drain out all of the hydraulic oil in the tank.

2. Remove the four hexagonal bolts (M8 × 20L) securing the top plate and tank, and hoist the motor by its suspension plates to separate it from the tank.

3. This will reveal the suction strainer: loosen it with e.g. an adjustable wrench and remove it.

• Air blow the filter section to blow off deposits and adhering material. Also remove dirt from inside the strainer’s cylinder.

• After completing the cleaning, reassemble by following the removal procedure in reverse. The tightening torque for the hexagonal bolts that secure the top plate and tank is 5.9 N⋅m. After completing reassembly, check that the unit runs normally by following the test run instructions.

WARNING! When using air blow, wear protective glasses to avoid getting deposits and dirt in your eyes.;

When using the unit with a set pressure of 6 MPa or higher, if the pressure becomes unstable due to the effects of contaminants, etc., mount the fixed throttle (φ0.8) provided as an accessory. Check that there is no residual pressure before mounting it.

1. Remove the hexagon socket head T plug (Rc 1/4).

2. Mount the fixed throttle (NPTF1/16 × φ0.8).

3. Wrap sealing tape around the hexagon socket head T plug (Rc 1/4) and fit it as it was.;

If any of the three conditions below is applicable, readjust the safety valve.

1) Although the setting is such that even when used at the maximum pressure setting, the safety valve will not actuate under normal pressure control (there is an exception during transition to the main machine’s hydraulic circuit blockage due to a stop of a hydraulic actuator, for example), the set pressure of the safety valve drops and it actuates even in the normal status due to repeated operation over a protracted period or contaminants in the hydraulic oil.

• When the oil temperature rise has become faster in comparison with how it was previously.

• When, in the pressure holding state with the motor speed displayed, turning the safety valve adjusting screw in the tightening direction lowers the motor speed.

2) When, for reasons such as the restricted withstand pressure of the hoses used, it is desired to as far as possible suppress surge pressures that greatly exceed the set value.

3) When the pressure setting has been changed after shipment from Daikin. For the purpose of suppressing surge pressure in order to protect the main machine’s actuator and peripheral devices such as pressure gauges, it is advisable to set the safety valve setting to “unit set pressure + 0.5 MPa”.

1. Referring to the enlarged view of the safety valve on the next page, loosen the lock nut. (Lock nut: M10, width across flats of 14 mm)

2. In accordance with the guidance diagram for the length of the pressure adjusting screw, bring the screw to about the length corresponding to the desired control pressure. (The tip of the adjusting screw has four faces, with width across flats of 7 mm.)

3. Turn on the power to the hydraulic unit, establish the setting mode by panel key operation, and adjust the pressure setting to the desired pressure.

• Wear protective glasses and gloves for this work, and do it with the power OFF.

• When using air blow, take care to avoid getting foreign matter in your eyes.

• Note that oil will flow out from the piping during disassembly. Also, check that there is no residual pressure in the piping before starting the work.

• When the hydraulic oil in cylinders and piping is returned to the tank, the tank may overflow. Rather than returning the hydraulic oil in cylinders to the tank, collect it in a separate oil receiver.

• Check that there is no abnormal noise, abnormal vibration, or abnormal heat generation from this product.

1. Oil hue check. Degradation of the hydraulic oil can be recognized based on its color. If the hydraulic oil color changes toward brown and reaches ASTM level L4: bright yellow, replace it.

2. Check that there are no cracks or breaks in the sheathing of the wiring.

3. Measure the insulation resistance, and check that it has not dropped.