Simrad Reversible Pump RPU80/160/300
An automatic "Rudder test" function in these autopilots will also limit the output equivalent to a rudder speed of 8 degrees per second which is optimum for autopilots with proportional rudder control. (Equals to approx. 9 seconds for
If the pump unit is used with older autopilot models like AP2500, AP200 or AP45, using J1000B, J101A or J45A junction units, the output level/flow rate is set by a potentiometer within the junction unit.
External rudder speed control can be provided by a separate potentiometer connected to J1000B/J101A/J45A and mounted near the steering position.
The flow rate must be chosen such that optimum automatic steering is obtained.
Experience has shown that a rudder time between 10 and 15 seconds hard over to hard over normally gives the best steering performance. In order to achieve a rudder time within these limits, the flow rate must correspond with the cylinder volume.
Some boats will perform good automatic steering even with a hardover time of 20 seconds. The
On page 7 to 11 are listed some well known hydraulic steering gears together with the corresponding values for the rudder time hardover to hardover.
The values are calculated from the maximum flow rate at 10 bar pressure.
If a specific system is not listed, the cylinder volume must be calculated as explained in section 2.1.
Any well known hydraulic oil with viscosity between
Use higher viscosity in warmer areas.
6 | 20220422N |