Cut-Off Valve Monitoring - Danfoss PVED-CLS User Manual

ENGINEERING TOMORROW
Important
Danfoss recommends not to change the default values for P3074, P3076 and P3097.
Contact your local technical support at Danfoss Power Solutions if there is a need to change these parameters.
Name
Cut-off valve present P3072 U8
Cut-off valve control
P3073 U8
mode
Cut-off valve CL pull
P3074 U16
current
Cut-off valve CL hold
P3076 U16
current
Cut-off valve PWM pre-
P3097 U8
load value
7.1.1.2

Cut-off valve monitoring

The PVED-CLS is indirectly doing diagnostics on the Cut-off valve whenever switching
conducted. The PVED-CLS checks that the EH-spool can move within the mechanical dead-band when it is
commanded to do so and the Cut-off valve is turned on, within the threshold, specified by P3078. By moving the EH-
spool in the mechanical dead-band, we ensure no oil flow is send to the steering cylinders.
Furthermore, the PVED-CLS also checks that the EH-spool cannot move when the Cut-off valve is turned off, even
though the EH-spool is commanded to.
Important
Electro-hydraulic steering (Auto-guidance, quick steering and AUX-steering) will not be enabled before the PVED-CLS has
passed this test.
Warning
By setting P3078 to 0, the Cut-off valve diagnostics are disabled.
Important
In most cases this test will be completed within 1 second, but if the oil has a very high viscosity, the time for completing this
test will increase; hence Danfoss recommends a relatively high value for P3078 to ensure the PVED-CLS does not goes into
fail safe mode in cold conditions.
Important
If PVED-CLS is commanded to go to off-road mode before pump pressure is available, PVED-CLS will not be able to perform
this self-test and hence fail after the specified timeout set by P3078.
Description of parameter
Cut-off Valve Present/Not Present
BOOL
Valid Values: 0 (NOT PRESENT); 255 (PRESENT)
Cut-off Valve control mode Close loop Control or ON-OFF control
BOOL
Valid Values: 0 (ON-OFF control); 255 (Closed loop control)
mAmp Current required to activate Cut-off valve
mAmp Current required to maintain Cut-off in ON state
% Cut-off valve PWM pre-load value
OEM
OEM
OEM
OEM
OEM
Table 8
Range
0 255 255 S
0 255 255 S
100 2000 1100 S
100 2000 500 S
0 100 100
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