Actuator Bracket; Figure 3-1. Diesel Engine Travel Stops; Figure 3-2. Use Proact Travel Stops For Carburetors - Woodward ProAct III Installation And Operation Manual

ProAct III/IV Actuator/Driver Manual 04127
Fuel Position Stops
Diesel Stops—Diesel installations will generally use the fuel system minimum
and maximum position stops. Diesel engine racks are normally designed to
provide the minimum and maximum stops without binding.
The actuator's stops must not prevent the actuator from driving the fuel linkage to
the minimum and maximum positions. The linkage should be designed to use as
much actuator travel as possible, without preventing minimum and maximum fuel
positions (see Figure 3-1).

Figure 3-1. Diesel Engine Travel Stops

Figure 3-2. Use ProAct Travel Stops for Carburetors

Gas Engine Stops—Butterfly valves in carburetors will often bind if rotated too
far toward minimum or maximum. For this reason, the stops in the actuator
should be used at both minimum and maximum positions. Note that the stops will
allow up to 3 degrees of additional rotation in both directions during impact (see
Figure 3-2).
The engine must always shut down when the actuator is at the minimum stop.

Actuator Bracket

The actuator may be installed on a bracket which attaches to the base with four
M8x1.25 (0.312-18) screws with a minimum engagement of 16 mm (0.625 inch).
The actuator may be mounted in any attitude. The actuator is weatherproof and
resistant to the corrosive effects of water and salt water. Avoid pressure washing
near the shaft seals.
The ProAct III actuator weighs 11 kg (25 lbs), and the ProAct IV actuator weighs
19 kg (42 lbs). The bracket and attaching hardware must be designed to hold the
weight and to withstand the vibration associated with engine mounting. The
bracket must also be designed to provide a heat sink (heat transfer) from the
actuator to the engine block. Figure 3-3 provides an illustration of the mounting
bracket.
12 Woodward