[DG] [DG11] ACU 300 EV1

[ricardomann]

ACU 300 EV1
Solenoid valve . I have hydrolock steering fitted to my boat . I want to control my port and star bored steering cylinders . with a Cetop steering directional manifold 12 volt . same as you get on a constant running electro hydraulic steering assist autopilot pump.
my steering runs solely by engine driven pump . the helm is a hydrostatic steering valve same as you get on a tractor or dumper truck . it is not a pump only a direction control valve .

my question is do i divert the flow from my hydraulic steering helm to the electronic valve manifold with a 12v diverter valve ? or do i get them to both work at the same time ? What is correct way an autopilot should work ? the problem i have. is i don't think i can split the output from the pump and have both systems usable at the same time so that leave me with one or the other . i think that could get dangerous. can i have your help with this thanks.
Ricky

[Derek - Raymarine - Moderator]

Hi Ricardomann

Thank you for your enquiry.

The ACU300 will output voltage to a prt solenoid and a starbourd solenoid, more information can be found here .

In your installation you have a source of high pressure oil from the engine driven pump and you have hi pressure oil from this pump available at the helm position. You will need to check if there are check valves in the helmpump, these will prevent the hi pressure oil output from the new solenoid operated manifold discharging back through the helm pump instead of driving to the steering cylinders. Also you will need to take an output from the engine drive pump too to the new solenoid operated manifold. When the autopilot is not in operation or the solenoid valves shut, the oil will go nowhere, once one of the valves opens, the oil will pump into one of the steering cylinders.

You will need to check the solenoids in the manifold block are the correct rating - the previous link will identify the preferred solenoid rating. You will also need to ensure that the helm pump has check valves and that the manifold will support the requirement to both output hi pressure oil to the steering cylinder at the same time enable the lo pressure oil from the 'other side' of the steering cylinder to return back to the reservoir, (otherwise the steering system will become hydraulically locked)

You should be able to use both the manual steering and the autopilot at the same time, ( Not that you would use them normally), but in cases of emergency when you need to make a rapid manual helm correction, due to say an object in the water, then you can take control of the steering immediately and as long as you turn the steering wheel faster than the autopilot is pumping then the boat will dodge round the object.

regards
Derek

[ricardomann]

Hi the manifold side of the circuit is good . i have pilot operated check valves in the lines on output. its the feed from the engine driven pump i don't know how share the output of the pump with the helm and the manifold at the same time .

thanks Ricky

[Derek - Raymarine - Moderator]

Hi Ricky,

Normally the pump output will be split with a T piece to feed both the helm pump and the manifold at the same time

Thanks
Derek

[ricardomann]

Hi Derek
with a fixed displaisment pump its not posable to split the flow
the flow will follow the path of the leased resistance?
this is the problem i have with this installation
if i fit a diverter valve its helm control or manifold ?
thanks

[Derek - Raymarine - Moderator]

Hi Ricky,

With the helm pump stationary - that is to say - not being operated by hand, then the flow from the engine driven pump is not going anywhere anyway??? Unless this is some form of hydraulic system we have not heard of?

Do you have a schematic of the hydraulic system with full details?

Are you saying the output from the engine driven pump is recirculated when the helm pump is static? This will make the installation difficult because if you fit a diverter valve to the solenoid block, then when the solenoids are closed - ie no steering command from the autopilot, then the pump output will be shut off and may overpressurise the pump or damage the pipework. It may be possible to fit a combination of diverter and relief valve so that when the autopilot solenoids are shut the output from the pump can be returned to the recirculation system thereby avoiding any issues with overpressuring - but this is added complication and really you should take this up withthe steering gear suppliers as they will know more about this than we do.

Regards
Derek

[ricardomann]

yes the system in open centre and so is the manifold . so if i switch the 2 way diverter. it works helm or manifold depending on witch path the flow is diverted to
Thanks Ricardo

[Derek - Raymarine - Moderator]

Hi Ricky,

OK, so long as the pump is never going to output to a dead end, then this should work.

In other similar installations, we have had good feedback from customers using reversing autopilot pumps tee'd into the two hydraulic lines to the Steering cylinder, with the reservoir line from the pump feeding into the return line for the reservoir of the engine driven pump.

We see no reason the system you propose should not work, but in all cases, it is always best to check with the hydraulic steering manufacturers, as they are the experts in that field.

Regards
Derek

[ricardomann]

Thanks Derek for you help as always
Ricardo

[Derek - Raymarine - Moderator]

H iRicky,

Glad to be able to help,

Regards
Derek