User manual

Aerosoft H36 Dimona X 1.00 Manual
Page 14 of 21
PV-120 CONTROL UNIT
The propeller used on the Dimona X is a
MT-Propeller Elcoprop® MTV-1-A with a
max certified rpm of 2900. Propeller
blade pitch is changed through an
electromotor controlled by the PV-120-
a control unit. The unit is supplied with
electrical power through a circuit breaker that is located on the right side of the control unit
(marked with ‘4’). If the unit isn´t powered, the propeller blade pitch cannot be changed.
AUTO AND SEGEL SWITCH
The AUTO/SEGEL switch is used to toggle between the standard AUTO mode and the gliding
mode where the propeller is feathered for minimal drag.
The Auto position will set the control unit to act as a constant speed governor, which means
that a selected rpm will be attempted to be maintained. This is off course only possible if the
engine is throttled up to achieve that. Propeller rpm can be set via the rpm selection knob
within the range 1900-2900 rpm. If engine rpm is increased and reaches the selected rpm blade
pitch will increase towards a coarser setting and torque demand will raise, thus keeping engine
rpm on the selected setting – or at least attempting so.
If blade pitch is at full fine position a green led light, labelled START will be lit - indicating that
the propeller is in the right position for take-off.
The SEGEL position will start feathering the propeller blades. The pitch control mechanism is
rather slow, so expect approximately 1 minute and 20 seconds from full fine to feathered
position. Near full feathered position the torque exceeds what the engine can deliver and the engine
will be bogged down and stopped. The right procedure is to turn off the engine before feathering the
propeller. It should also be moved out of feathered position before starting the engine.
Note: A small trick, for which the Dimona definitely not is certified, is to turn the propeller unit
circuit breaker off when the START LED is lit. This will lock the blade pitch at full fine position. By
doing that, the propeller will act as a fixed pitch propeller. The engine can now reach 3300 RPM,
giving maximum performance for take-off, something that could get you out of a short field. Just
note that the engine can´t run forever at 3300 RPM, - neither so in the Aerosoft Dimona. Keeping
RPM above 3000 for more than a couple of minutes and there is a high risk that the engine will be
wrecked.