6  RHD250 to 4000 (Contrac) ELECTRICAL ROTARY ACTUATOR |  SEI/RHD250/4000-EN REV. A   
3  Lubrication 
 
Mounting position 
The spur gearing of the actuator RHD250 / RHD500 / RHD800 / 
RHD1250 / RHD2500 / RHD4000 (Contrac) are lubricated with 
oil. They contain the max. oil quantity when leaving the 
manufacturer. Once the actuator is installed replace the 
uppermost check plug by the separately supplied venting plug. 
 
 
  Control screw 
  Vent valve 
Figure 2:  Permissible mounting positions 
 
The mounting positions presented are permissible. To facilitate 
mounting and maintenance, however, it is recommended that 
you use position IMB 3 For each mounting position, you should 
check the specified oil level before commissioning, see Filling 
volumes on page 7. 
 
To achieve this, allow for the following minimum distances: 
 
  40 mm (1.
 
 
 
Oil change 
Note 
Oils for different temperature ranges may not mixed.  
During an oil change, thoroughly remove any oil that may have 
escaped to avoid accidents.  
Dispose of old oil according to local regulations. Make sure that 
the oil does not enter the water cycle. Make sure that any oil 
leaking from the device cannot come into contact with hot 
components. 
 
Proceed as follows to drain or change the oil: 
1.  Provide a collecting vessel capable of holding the expected 
oil quantity in accordance with Filling volumes on page 7 . 
2.  Open and release the vent valve, see Mounting position on 
page 6. 
3.  Unscrew the lowermost drain plug to drain the oil. 
4.  Collect the oil in the collection vessel. 
5.  Make sure all of the oil has been removed from the actuator 
housing. 
6.  Screw the drain plug back in. 
7.  Refill with the proper volume of oil in accordance with Filling 
volumes on page 7 and securely tighten the vent valve.