MTS Material Test Systems - Manual (Page 29)

Ensure Correct Cable Connection
If a system cable has been disconnected, ensure that you establish the correct cable-to-connector relationship
during reconnection. Incorrect cable connections can result in improper servo loop phasing or an open servo
loop condition, either of which can cause unstable or unexpected and potentially dangerous system motions.
Verify the correct cable-to-connector relationship by observing the cable and connector labeling and the
system wiring schematics.
Keep bystanders safely away
Keep bystanders at a safe distance from all equipment. Never allow bystanders to be in close proximity of
specimens or equipment while the test is running.
Wear proper clothing
Do not wear neckties, shop aprons, loose clothing or jewelry, or long hair that could get caught in equipment
and result in an injury. Remove loose clothing or jewelry and restrain long hair.
Remove flammable fluids
Remove flammable fluids from their containers or from components before you install the container or
component. If desired, you can replace the flammable fluid with a non-flammable fluid to maintain the proper
proportion of weight and balance.
Know compressed gas hazards
Your system may contain accumulators that require a high-pressure gas precharge (pressures that exceed
138 bar [2000 psi]). High-pressure devices are potentially dangerous because a great amount of energy is
available in the event of an uncontrolled expansion or rupture.
Observe the following safety practices when you work with high-pressure air or gases:
• When you charge an accumulator, follow all the charging instructions provided in the appropriate product
information manuals. When precharging accumulators, properly identify the type of gas to be used and
the type of accumulator to be precharged.
• Use only dry-pumped nitrogen to precharge nitrogen-charged accumulators. (Dry-pumped nitrogen can
also be labeled “oil pumped” or “dry water pumped.”) Do not use compressed air or oxygen for precharging:
the temperature increase caused by rapid gas compression can result in highly explosive conditions when
hydraulic fluid is in the presence of oxygen or compressed air.
• Always follow the recommended bleeding procedures before you remove or disassemble components
that contain pressurized gas. When you bleed a gas or remove a fitting, hose, or component that contains
a gas, remember that many gases cannot support life. Therefore, as the ratio of released gas to oxygen
increases, so does the potential for suffocation.
• Wear appropriate safety devices to protect your hearing. Escaping air or gas can create a noise level that
can damage your hearing.
• Ensure that all pressurized air or gas is bled out of a pneumatic or gas-charged device before you start
to disassemble it. A thorough understanding of the assembly and its pressurized areas is necessary before
you undertake any maintenance. Refer to the appropriate product information for the correct bleeding
procedure.
It may not be obvious or intuitive which bolts or fittings are used to restrain a pressurized area. On some
assemblies, you must remove a cover plate to gain access to the structural bolts. Sometimes, to protect
you from a rapid release of trapped gases, a small port is exposed when you remove this cover plate.
Exposing this port ensures that the gas precharge is fully bled before disassembly. However, this is not
MTS Material Test System Operation 29
4.0 Safety