Danfoss PVG 16 PVAS, Техническая информация

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All proportional control PVG 16 actuators feature:
•
Integrated fault monitoring
•
Detecting spool stroke inconsistencies
•
Detecting internal hardware defects
•
Detecting demand signal inconsistencies
•
Fault reaction depending on the type of fault monitoring
‒ Generic
‒ Specific
The PVEA comes with a passive fault monitoring.
Passive fault monitoring
Passive fault monitoring does not disable the solenoid valves when an error is detected. It will continue
to operate despite that an error was detected. When the error no longer is registered the passive fault
monitoring will “forget” the error and continue as if the error was never there.
With a passive fault monitoring the following conditions will happen when an error is detected/occurs:
•
The LED light will switch from green to red and the error pin output will go high
•
The solenoid valves will continue operating at the set point given at the time of the error
‒ Only exception is if the error is caused by the supply voltage (U
DC
) being either above or below
the allowed range or if the temperature measured on the internal electronics board is higher than
allowed. In these cases, the solenoid valves will be disabled.
Generic Fault Reaction
All PVE actuators with fault monitoring are triggered by the following main events:
Control Signal Monitoring The Control signal voltage (U
S
) is continuously monitored.
The permissible range is between 15% and 85% of the supply voltage (U
DC
).
Outside this range the PVE will switch into an error state. A disconnected U
S
pin (floating) is recognized as a neutral set point.
Transducer/LVDT Supervision
The internal LVDT wires are monitored. If the signals are interrupted or short-
circuited, the PVE will switch into an error state.
Supervision of Spool Position The actual position must always correspond to the demanded position (U
S
).
If the actual spool position is further out from neutral than the demanded
spool position or in opposite direction, the PVE will switch into an error state.
Spool position closer to neutral and in same direction will not cause an error
state – the situation is considered
in control.
Float Position Monitoring
Float position must be entered or left within a time limit.
A too high delay on the 1x6 pin float PVE will cause an error state – this is
relevant for the 1x6 pin PVEH-F actuators only.
Temperature Monitoring
When the temperature is too high the PVE LED will light constant red and
solenoid valves will be disabled.
Technical Information
PVG 16 Proportional Valve Group
Fault Monitoring and Reaction
84 | © Danfoss | December 2018 BC00000211en-000901