Valve Capacity - Danfoss PVED-CLS User Manual

ENGINEERING TOMORROW
When the EH spool position is forced to neutral, the closed loop control will try to correct the position to avoid the
overshoots by changing the gain in the regulation. (For details on the P3588 and P3589, refer Safety Manual).
Name
IMD - EH-Steering
disengage confidence P3586 U8
limit
IMD- EH-Spool in
P3587 U8
neutral confidence limit
IMD - Dynamic SVC
P3588 U8
integral limit
IMD - Integral gain P3589 U16
IMD - Threshold P3591 U16
Attention
How to verify the correct operation of IMD, follow below steps:
1. Check the status message 1 sent by CLS Main and Safety controller, for the requested spool position and actual
spool position. As mentioned above, if the requested spool position is <0.4mm, then the actual spool position is
either fixed to +0.4mm or -0.4mm (based on the previous EH-steering direction). When the steering wheel is
manually being turned, the actual spool position is forced to neutral. If the spool fails to arrive at neutral even
after the turning the steering wheel, then hydraulic over ride is failing to perform.
2. Check the hydraulic connections (for EHi hydraulic schematics refer EHi TI). There must not be any missing
connections in the EHi configuration.
3. Check the steering unit pressure, P-T bar in neutral to be below 14 bar (refer service manual of EHi). If higher
than 14 bar IMD may disable EH steering operation.
Important
The PVED-CLS is dedicated for IMD: It has built in check valves between pilot ends of the EH spool to the PE pilot
supply. In this way, its ensured there will be no hydraulic pressure on either end of the spool when the cut off spool
is in safe state, because the pilot supply is connected to tank. For IMD operation use only PVED-CLS including check
valves.
7.4

VALVE CAPACITY

The valve capacity parameter (P3088) must be set to the corresponding EH flow size.
P3088 indicates the EH-spool's (either in the OSPE, EHi-E, EHi-H or EHPS) maximum output flow, given in liters per
minute. The nominal value for the EH-spool's maximum output flow can be found on the OEM's customer drawing.
Depending on the standby pressure for the steering system, the actual maximum output flow will deviate. As default, the
nominal value will in most cases give a very acceptable steering performance in fast-steering mode but for fine-tuning of
P3088, please contact your local Danfoss representative.
© Danfoss | August 2018
Description of parameter
Timeout value to declare steering movements to be active if EH-Spool
x10ms
stays within the limit specified by P3090.
If EH-Spool stays within the threshold specified by P3090 for the timeout
x10ms value specified by P3590, IMD overrules EH-Steering algorithms and takes
over spool control to evaluate spool position.
- Dynamic SVC integral limit to use while EH-Spool is close to neutral
0,1 Dynamic SVC integral gain to use while EH-Spool is close to neutral.
x10u Meter Sterring activation spool threshold is close to neutral
Range
OEM 0 255
OEM 0 255
OEM 0 255
OEM 0 65535
OEM 10 25
AQ00000211 | 43
30 S
15 S
25 S
225 S
15 S