Ac1, Ac3, Ax, C-Load Specifications - ABB i-bus KNX Product Manual

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ABB i-bus KNX
Device technology
2.3

AC1, AC3, AX, C-Load specifications

In intelligent installation systems, different switching capacity and performance specifications, that are de-
pendent on the special applications, have become established in industrial and building installations. The-
se performance specifications are rooted in the respective national and international standards. The tests
are defined so that typical applications, e.g. motor loads (industrial) or fluorescent lamps (residential), are
simulated.
The specifications AC1 and AC3 are switching performance specifications, which have become estab-
lished in the industrial field.
Typical application:
AC1
AC3
AC5a
These switching performances are defined in the standard EN 60947-4-1 Contactors and motor-starters -
Electromechanical contactors and motor-starters. This standard described motor starters and/or contactors
which were previously used primarily in industrial applications.
The designation AX has established itself in the field of building engineering.
AX relates to a (capacitive) fluorescent lighting load. Switchable capacitive loads (200 µF, 140 µF, 70 µF
or 35 µF) are referred to in conjunction with fluorescent lamp loads.
This switching capacity refers to the standard EN 60669 Switches for household and similar fixed electrical
installations – General requirements, which deals primarily with applications in building engineering. For
6 A devices, a test with 70 µF is demanded, and for devices exceeding 6 A, a test with 140 µF is demand-
ed.
The switching capacity specifications AC and AX are not directly comparable. However, the following
switching capacity quality can still be determined:
The lowest switching capacity corresponds with the specification AC1 - mainly for resistive loads.
The following switching capacity should be rated higher AX - fluorescent lighting load to the standard:
70 µF (6 A), 140 µF (10 A, 16 A).
The highest switching capacity is designated by AC3 - motor loads,C-Load - fluorescent lighting loads (200
uF).
Both specifications are almost equivalent. This means that a device, which has fulfilled the test for AC3 to
EN 60947, will most probably fulfil the tests to EN 60669 with 200 µF.
In conclusion, the following can be said:
•
Users or customers, who are primarily involved with industrial applications, will refer to AC3 switching
capacities.
•
Users, who are involved with building or lighting technology, will more often than not refer to an AX
switching capacity or C-load (200 µF loads).
The switching capacity differences must be considered with the selection of an Energy Actuator.
Non-inductive or slightly inductive loads, resistive furnaces
(relates to switching of resistive loads, cos φ = 0.8)
Squirrel-cage motors: Stating, switching off motors during running
(relates to (inductive) motor load, cos φ = 0.45)
Switching of electric discharge lamps
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