Current Detection; Planning And Application - ABB SA/S 12.16.6.1 Product Manual

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ABB i-bus KNX
4 Planning and
application
4.1

Current detection

Planning and application

In this section, you will find some tips and application examples for practical
®
use of the ABB i-bus Switch Actuators.
The current detection feature opens many new fields of application for the
Switch Actuators. The following list contains a few examples:

Load current flow detection (from 20 mA)
Detection of significant equipment failure
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Preventative recognition of failures by continuous current monitoring
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Actual recording of operating hours
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Signalling of maintenance and service work
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Detection of open circuits
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Recording of switch operations per period
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Energy and load management
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Monitoring and signalling
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Note
Only load currents with a sine wave characteristic can be detected
correctly. For 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.
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 less than 30 mA, mains voltage and current
fluctuations due to ambient influences, e.g. temperature and natural
ageing of the device 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.
In the following, there are some application examples described in more
detail for current detection.
SA/S | 2CDC 505 056 D0207 133