Which Evolution autopilot is correct for a powerboat w/hydraulic steering?

[Chuck - Raymarine - Moderator]

Which Evolution autopilot is correct for a powerboat w/hydraulic steering?

When seeking an autopilot for a vessel with hydraulic steering (not to be confused with cable driven / power assisted steering common to I/O powered vessels), the first step is to determine the cubic capacity (specified in cubic centimeters (cc) or cubic inches (ci)) of the vessel's steering ram(s). The cubic capacity of the steering ram(s) is typically stamped onto a plate affixed to the steering ram. Alternatively, the manufacturer of the steering ram may be contacted to obtain this information. Should the vessel be equipped with more than one steering ram, then it will need to be determined whether the steering rams have been plumbed in series or parallel. The total capacity of hydraulic fluid that will need be pumped through steering rams which have been plumbed in series will be equal to the capacity of one of the steering rams. The total capacity of hydraulic fluid that will need be pumped through steering rams which have been plumbed in parallel will be equal to sum of the capacities of each steering ram.

After having determined the capacity of hydraulic fluid that will need be pumped through steering ram(s), an autopilot hydraulic pump will be selected. As the capacities of the hydraulic pumps overlap, some discretion should be used in selecting the appropriate pump for the vessel. Service life and performance of the autopilot will typically be maximized by installing the higher rated of two hydraulic pumps which support the capacity of hydraulic fluid which will need be pumped through steering ram(s). One should not install a hydraulic pump having a minimum specified hydraulic capacity which exceeds the capacity of hydraulic fluid which will need be pumped through steering ram(s).

NOTE: When used with an ACU-150 or ACU-200, a Type 0.5 pump may be used in hydraulic steering systems equipped with rams having capacities up to 150cc (9 cu. in.). When used with the ACU-100, it is recommended that it not be used in hydraulic steering systems equipped with rams having capacities greater than 110cc (6.7 cu. in.) in offshore and/or heavy use applications. The ACU-200 may be used with 12V or 24V systems, while the ACU-150 may only be used with 12V systems.



After having determined the model of hydraulic pump that will be installed onboard the vessel, then the model of Evolution Autopilot Actuator Control Unit (ACU) will be determined based upon the model of autopilot hydraulic pump that will be installed onboard the vessel. See the table above specifying the model of Evolution Autopilot ACU which will be used for each model of Raymarine autopilot hydraulic pump.

The remaining components which make up an Evolution autopilot for a hydraulically steered vessel include an EV-1 Evolution Autopilot Sensor Core, a p70 or p70R Autopilot Control Head(s), and an optional rudder reference transducer.

Note: autopilot control heads are optional, but recommended, for vessels equipped with Raymarine a/c/e/eS/gS-Series MFDs. A p70 or p70R Autopilot Control Head must be installed when interfacing an Evolution autopilot system any other model of Raymarine MFD or third party chartplotting device.

While the components for Evolution autopilots may be individually purchased and part number found here, Raymarine offers the following Evolution Autopilot bundles which include: EV-1 Sensor Core, ACU, hydraulic pump, Evolution Autopilot SeaTalkng Cabling Kit. The following Evolution autopilot bundles are available for hydraulically steered powerboats:
- T70154 EV-100 Power
- T70330 EV-150 Hydraulic
- T70157 EV-200 Hydraulic Pack
- T70162 EV-400 Power

Note: The information specified within this FAQ may also be found on the Hydraulic tab of Raymarine's Drive Unit Selection web page and Table 1-1 of the Raymarine Hydraulic Pump Installation Guide. As product specifications and product documentation are subject to change, it is recommended that customers seeking the latest product specifications consult Raymarine's product web pages and the latest Raymarine product manuals accessible via Raymarine's Manuals and Docs web page.


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