Instron 300DX, Operating Instructions Manual

Page: 60 / 96

Chapter 3: Operation
60 M47-17027-EN
Loss of power
If at any time main power is lost to the frame (due to the disconnect switch being turned off,
Emergency Stop
being engaged, power loss at the customer power supply, or complete power loss to
facility), gravity will cause the frame to go to its natural resting state, i.e. the piston will retract into the
hydraulic cylinder. To impede this process, the system is equipped with a valve that closes at loss of
system power and prohibits oil leakage from the hydraulic cylinder. However, it can not stop 100% of oil
leakage and thus the hydraulic cylinder will drift very slowly. Drift is slow enough that a noticeable
amount of drift may be seen if system power remains off over an extended period (i.e. several days). Even
with this very slow drift rate, multiple pinching hazards may exist on the frame (depending on accessories
mounted in the test space) and personal injury is still possible. Also, any equipment in the tension test
space may be damaged. If possible, remove any specimens from the frame.
If power can not be restored to the frame and it is necessary to retract the piston into the hydraulic
cylinder, contact your local Instron Services department as directed on page
20 for a solution.
Warning
Caution
On loss of power, any equipment in the test space may be damaged, particularly
extensometers. It is always good practice to keep equipment that is not currently in use out
of the test space.
It can be verified that the piston is fully settled to the bottom of the cylinder by the following:
•
Measure the distance between the bottom of the compression table and the top of the base plate.
This distance should be less than the following:
• 300DX: 64 mm (2.5 in)
• 600DX: 105 mm (4.125 in)
•
If power has been off for at least 5 minutes.
•
Visually observe the loading unit for movement.
On loss of power, immediately remove hands and arms from the frame to avoid personal
injury.