Pilz PSS SB HYD, Basic license - Manual (Page 194)

6-132 Modular Block System: Hydraulic Presses
Standard Function Blocks
Safety guidelines for input parameters TOn and TOff
• The reaction time (input parameters TOn and TOff) must not adversely
affect the availability of the press.
• Please note that pressure and temperature fluctuations can vary the
valve's reaction times.
• Please note that the clearance distance from the machine must be
calculated in accordance with the values established by measuring the
overrun on the press.
• Please note that the overrun of the machine will be determined by the
reaction time of the valve.
If the switching times of the valves increase during the lifetime of a
machine, the overrun distance will also increase. This means that the
safety distance will need to be increased. Always check that the reaction
times are set correctly (input parameters
TOn and TOff). This is the only
way in which SB087 can sensibly monitor the reaction times on which the
safety distance is based, detect the valve's increased reaction times and
therefore switch the valve to a safe condition (start position).
• Reaction times should be set as short as possible (input parameter TOn
and TOff).
WARNING!
If the time values entered for TOn and TOff are too long, serious injuries
could result should the danger zone be accessed during operation.
The reaction time of the safety valve determines the stopping time of the
press on an emergency stop. The stopping time determines the safety
distance to the tool.
Reaction times should be included in the calculation of the safety
distance if the time values you are setting for the parameters
TOn and
TOff are significantly higher than the actual valve reaction times.
• Please note:
- With directional control valves (input parameter VTyp = 0), the reaction
time when the valve switches on and off must always be monitored
(see under “Settings for the parameters
TOn and TOff).
- With poppet valves, the reaction time when the valve switches on and
off may be monitored (see under “Settings for the parameters TOn and
TOff”).
SB087