Agromatic NEx Series, Assembly And Operating Manual, Page: 25 / 112

3 Product description 3.3 Functional description
Actuators NEx, NEx-K, NEx-KA, NEx-V 19
3.3 Functional description
The actuator has been designed to operate industrial valves (e.g. dampers,
ball valves, other valves) within the regulating distance determined by the
mechanical characteristics of the valve. Depending on the design of the actu-
ator, it is possible to move only to the valve end positions or to any position
between the end positions.
The actuator can be installed in any orientation.
The actuator is installed either using a bracket or an adapter but can also be
attached directly to the valve if required. If a bracket is used, the actuator is
mounted to the valve by means of a coupling.
Different brackets are available for various requirements.
The actuator is either equipped with a brushless DC motor (BLDC motor), a
DC commutator motor or a synchronous motor.
In case of a power failure the actuator can be operated manually by a hand-
wheel.
In order to ensure safe operation even at lower temperatures, the actuator
features a heater.
Safety devices for application in potentially explosive areas
Flameproof enclosure
The housing has been designed as a flameproof enclosure, i.e. the housing
design prevents the distribution of an explosion from within the actuator to the
atmosphere around the actuator.
Temperature switch
The actuator features a temperature switch with a manual reset mechanism.
The temperature switch triggers at a temperature > 80 °C and the actuator is
switched off. After waiting for at least 60 minutes and making sure the actua-
tor has cooled down by at least 10 K, manually reset the temperature switch
before switching the actuator back on (see section
“8.3 Resetting the tem-
perature switch” ).