MTS Series 244 Actuators - Manual (Page 54)

Multiple Fixtures With Different Ratings
Sometimes you may have multiple fixtures in the force train that have different force ratings. When removing
the fixtures pretensioned with spiral washers, remove the fixtures with the lowest force rating first. Then
remove any other fixtures from the lowest to the highest force rating.
1. Ensure that system hydraulic pressure has been reduced to zero before proceeding. To do this, turn off
the hydraulic power unit and exercise the actuator until it stops moving.
2. Install a dummy specimen or a suitable fixture in the force train such that it can withstand a tensile load
10–20% greater than the maximum load to be applied during testing.
3. Select force control at the system controller.
4. Apply system hydraulic pressure according to applicable system procedures.
Warning:
Do not exceed the maximum HPS output pressure or apply a force greater than any force
train component capacity.
Exceeding the tensile load capacity of any element in the force train can cause equipment
damage or personal injury.
It is necessary to temporarily exceed the tensile load capacity to achieve the requirements of
Step 5 in this procedure. This is accomplished by increasing the output pressure of the HPU.
Contact MTS Systems Corporation.
Note:
Be sure that all components in the force train can accommodate the required tensile load.
5. Apply a static tensile load 10 to 20% higher than the maximum load to be applied during testing.
6. Use the spanner wrenches to rotate the spiral washers to reduce their combined thickness to a minimum.
7. Reduce tensile load to zero and remove hydraulic pressure. Ensure that all residual pressure (including
accumulator pressure) has bled off.
8. Remove all force train components (such as load cell, swivel rod end, grips, or fixtures) attached to the
actuator.
LVDT Cable Connection
The following figure shows the electrical connections of the LVDT. See your controller manual for cable
specifications or cable assembly numbers.
54 Series 244 Actuators Product Information
Installation