It important to consider the number of actuators in both the power loop and the
signal loop when using bus-based communication. The loop list should be
finalized and approved before installation of the cable is started.
In case of power loss, none of the actuators in that power loop can be remotely
operated. In case of a signal loss, none of the actuators on that signal loop can
be remotely operated. Manual operation is however possible in both scenarios.
With the Dual CAN and the Failsafe options the system security in case of a
power or signal loss is largely enhanced. More details are found in Appendix A
Dual CAN Option on page 59 and in Appendix B Failsafe Option on page 65.
The power consumption varies depending on whether the actuator is in standby
mode or is running, see Table 5: System performance parameters for QT250 and
QT800 actuators on page 19.
Eltorque actuators may be used according to IEC 60034-1 duty type S2
Industrial Valves – Actuators, chapter 4.7:
For class A - ON/OFF operation, duty performance is defined as the minimum
number of cycles per hour, where "one cycle consists of nominal 90° angular
travel in both directions (i.e. 90° to open + 90° to close), based on an average
load of at least 30 % of the rated torque with the ability to transmit 100 % of the
rated torque for at least 5 % at each end of travel, with a cumulative operating
time not exceeding 15 minutes in one hour." (EN 15714-2, chapter 4.7.2.2, a.).
For class B - inching/positioning, duty performance is defined as the minimum
number of starts per hour, where "one start consists of a movement of at least 1°
in either direction, with a load of at least 30 % of the rated torque. The cyclic
duration factor (i.e. the ratio between the running period and total period)
shall be not less than 25 % (e.g. 1 s. running and 3 s. resting)" (EN 15714-2,
chapter 4.7.2.2, b.)
For classes C and D - modulating and continuous modulating, duty performance
is defined as the minimum number of starts per hour, where "one start consists
of a movement of at least 1°. in either direction, with a load of at least 30 % of
the rated torque" (EN 15714-2, chapter 4.7.2.2, c.).
Rotating electrical machines, chapter 4.2:
Duty type S2: "Operation at constant load for a given time, less than that
required to reach thermal equilibrium, followed by a time de-energized and at
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