ABB SA/S 12.16.6.1 Product Manual - Knx Device
ABB i-bus
®
KNX Device
technology
SA/S | 2CDC 505 056 D0207 31
Note
Only load currents with a sine wave characteristic can be detected
correctly. On other signal types, e.g. phase angle or inverse phase angle
control signals, the detected current value is distorted. In this case, the
measured value is meaningless.
Current values less than 20 mA are indicated as a 0 mA value on the
KNX. For small load currents that are just above the minimum detection
threshold of 20 mA, it is possible that a value of 0 mA is displayed due to
the inaccuracies, even though a current is flowing.
Example: A current of 25 mA is flowing. The Switch Actuator detects 5 mA
due to the tolerances. This value is less than the minimum current
detection limit of 20 mA and is thus sent as a 0 mA value on the KNX.
Important
The function current detection and monitoring should only be used for
safety relevant applications. The Switch Actuator cannot assume the
function of a circuit-breaker or RCD (earth-leakage circuit breaker).
If the load current detection is used for equipment fault detection that only
causes a slight change of under 30 mA, mains voltage and current
fluctuations due to ambient influences, e.g. temperature, natural ageing of
the device or a non-sinusoidal current, play a significant role. Even when
the current changes are detected by the Switch Actuator, the detected
current changes do not necessarily mean that a device has malfunctioned.