Hello, this winter i want to build my fist AOG setup on my NH T7.185.
It’s MJ 2015 and none Autosteer ready.
After reading here about the different setups, i came to the point to go for a Danfoss EHi valve, but i have some questions for the configuration of the valve because there are many things to watch out.
20 l/min should be plenty. I’m using 10 l/min in the PVG.
If ypu have reaction type orbitrol, the reaction switch valve is needed
If you take with hydraulic disengage you don’t need sasa sensor, and afaik not even a separate pressure sensor. Can’t recall if it’s only available with the CLS steering controller, though.
The PVED-CC should work with the CAN code, just ask if you have problems, it’s from me originally.
Otherwise looks about right. I just tried to order one but my Danfoss dealer couldn’t order it as they are updating the valves and there’s no new technical manual yet with the new ordering codes, sounds bit weird…
The EHi design supports category 3 architecture according to ISO 13849-1. Fail-safe operation of
electrohydraulic steering is achieved by means of two individual spools, both supporting medium
diagnostic coverage 90-99%. The EHi is available with PVED-CLS steering valve controller to complete a
full CAT3 fail-safe steering valve. The PVED-CLS has steering specific functions, including dedicated safety
functions, which may be tailored for most off-road vehicles through software parameterization. The EHi is
offered with an independent 3rd party certification and a full steering sub-system specification
@wland the priority valve spring gives the delta pressure between CF and EF ports. If you pick too low a value, the steering will feel slow and heavy to turn. Too high and you’ll have excessive pressure loss.
7 bar seems to be quite common for tractors, you can always just swap the spring afterwards if there’s issues. You should be targeting around 1 litre/min flow or more in the dynamic LS line, which depends on the size of the LS orifice and the back pressure in the tank line.
Looks like Danfoss recommends 7 l/min and 1.2 mm LS and 1.0 mm dynamic orifice together with EHi if using an external priority valve. That gives bit over a liter flow to the LS line so should be good.
Looks like the EHi Valve is really hard to get. I asked for some quotes at our local danfoss dealers but didn’t get anything back or got the answer that the valve is locked for aftermarket sell. (Asked for the version with electrical disengagement).
So probably i’ll go for the pvg16 setup. @nut : how does the shut-off valve work in your setup. Is it just a 6/2-Valve?
I have one on order now, 16 weeks delivery time though. I plan to make an aftermarket bolt-on kit based on the Danfoss stuff when get a couple of protos ready first.
I don’t have any cut-off with the PVG, just electrical switch cutting power from the steering bus. You could add on off to A/B ports, or put a 6/2 with plugged ports to the steering lines. Don’t put a 6/2 switch valve in between for safety, it’s probably just worse.
Nice to hear that you were able to order it. Wich config have you ordered?
I know steering lines to the orbitrol should always be open but what will happen on the steering wheel when EH steering is activated (reaction type orbitrol)?
Probably a double pilot operated check valve would solve the problem?
20 l/min non-reaction with PVED-CC and SASA for disengage. Have one OSPE with CLS under work as well.
Reaction steering wheel will spin in EH mode, then you should use the 6/2 in between with PVG or use EHi version with the built-in reaction switch over valve. Double pilot check, how were you thinking to install?
The check valve could be placed right after the orbitrol L/R lines so it only opens when pressure is coming from one side of the orbitrol. At the same time the second line will also open. When pressure comes only from EH and cylinder side the check valve is closed on both lines. Then the steering unit should be none reaction. Shock valves could be needed then i think. But i don’t know how fail-safe that would be or if it influences how smoth the orbitrol steering is.
I have used a 6/2 valve. Works well. With a double check valve you need a minimum pressure to open it so i didn’t knew if it works smooth for normal steering but would be worth a try. Probably a combination of the 6/2 valve and a check valve just in case if the 6/2 valve hangs would be an option.