Integrated Safety Devices - Leica ASP300 S Operating Manual

2.3 Integrated safety devices

Overpressure protection
Overcurrent protection
Overheating protection
Over vacuum protection
Overcurrent protection
Leica ASP300 S
In the case of power failures or other processing problems the Leica
ASP300 S incorporates specimen protection features such as a fluid level
sensor and sophisticated software controls which ensure that processing
can be completed successfully without damage to the tissue specimens.
• When power is off the air pump and air valves default to a safe condition
(retort vented, no pressure generation).
• If the microprocessor control fails to stop the air pump at the right
moment during retort pressurizing, a separate electronic hardware
circuit will cut pump power.
• In addition, there is a safety relief valve that vents all excess air pump
output to atmosphere.
• Overcurrent conditions are protected against by both the mains fuse and
the separate heating power fuses.
An error is indicated and all heating is stopped by the microprocessor
control if the instrument detects any of the following conditions:
• abnormally high temperature (>75 °C)
• contradictory results of the temperature sensors
• failure of one or more heating power control components
• If the microprocessor fails to interrupt heating power, independent
temperature limiting hardware circuits limit the temperature rise to a
safe level.
• If the temperature limiting circuits malfunction, an independent hard-
ware thermal fuse circuit cuts power to the heating elements.
• The vacuum system is not capable of generating a dangerous vacuum
condition.
• Overcurrent conditions are protected against by both the mains fuse and
the separate heating power fuses.
2. Safety
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