Pve-Ex Fault Monitoring; Direction Indication Feedback (-Di) - Danfoss PVE 7 Series Technical Information

Technical Information
Electrohydraulic Actuators PVE-EX
Safety and monitoring

Direction indication feedback (-DI)

© Danfoss | October 2017
the supply voltage exceeds 36 V
‒
the supply voltage falls below 8.5 V
‒
the internal clock frequency fails
‒

PVE-EX fault monitoring

Fault monitoring overview
PVE type
Fault monitoring
Delay before error out
Closed loop deactivated memory (reset needed)
No fault
Error mode
Input signal fault
Transducer (LVDT)
Close loop fault
C
Caution
The installation must be performed as intended in order to have a safe system.
Please refer to the information in this manual for an assistance, or consult with a professional.
PVE with build in indication for spool movement direction are available.
The PVE–DI has dual power supply. U
back. The PVE does not work without U
signal fault monitoring is disabled if U
The DI has two direction feeedback signals with output high (close to U
position. If the spool moves out of neutral position, the direction signal switches to low (< 0.2 V). One of
the signals goes low by spool ~0.8 mm out of neutral and high by spool within 0,4 mm out of neutral.
Both direction indication signals go low when the error indicator goes high.
Direction indication feedback
DI-A low
DI-B high
-0.8 -0.4 0
A-port
PVBS towards PVE
As shown in the figure, both "DI-A" and "DI-B" signals are "High" when the spool is in neutral position.
When the spool is moving in the A direction, the "DI-A" signal goes "Low" and the "DI-B" signal stays
"High". The reverse is true when the spool is moved in the B direction.
Values for Direction Indicators (-DI)
Transition from high to low
Transition from low to high
PVEH/PVES-U
versions
Active
500 ms
Yes
Error output status – Low
Fault output on PVE: < 2 V
Error output status – High
Fault output on PVE: U
only supplies solenoid valves. U
DC1
. DI-A and DI-B are relative standard mounting. The input
DC2
is disabled. DI-A and DI-B are relative standard mounting.
DC1
DI-A high
DI-B low
Spool position 'x'
0.4 0.8
mm [in]
B-port
PVBS away from PVE
0.8 ± 1 mm [0.031 in]
0.4 ± 1 mm [0.015 in]
PVES versions PVEO versions
Passive No
250 ms —
No —
—
—
DC
supplies electronics and feed
DC2
) when the spool is in neutral
DC
BC00000393en-US0102 | 23