Residual current analysis systems DRCA-1-Set
DRCA 1-Set measuring system for analysing discharge/residual currents

Function:
Measuring devices are used to detect residual currents or current consumption levels. Due to the increasing use of type B RCDs to protect systems with power electronics equipment (e.g. frequency converters) there are also increasingly more trips from these RCDs to monitor without being able to identify a fault in the system using conventional analysis processes. The cause of these faulty trips are usually residual currents in the form of capacitive leakage currents with frequencies that deviate from the mains frequency and that flow to the earth via real or parasitical capacitance (e.g. EMC capacitors or line capacitance). Depending on the type of electronic equipment, leakage currents may have very different frequency mixes. As these residual currents on the earth resistance of the electrical system also cause touch voltage, they must be detected by an RCD and effect a trip. Measuring systems of this class facilitate the analysis of residual currents and residual current mixes with frequencies that deviate from the mains frequency. The analysis results usually point to the cause of the leakage current, thereby providing information on measures of how to reduce it in order to use a Type B RCD without problems. Measuring devices of series DRCA offer multi-layered analysis tools for determining the source of residual currents and the selection of suitable RCDs. The set consists of the following components: 1. DRCA 1 measuring unit: The DRCA 1 measuring unit analyses the measured values and prepares them for further processing on the PC connected to the unit via a standard USB port. 2. DRCA 1-MC measuring cable: The DRCA 1-MC measuring cable ensures correct transmission of the measured values to the measuring unit. 3. DRCA 1-CT70 measuring bushing transformer: The residual current transformer covers all of the active conductors leading to the consumers and uses its output signal to illustrate the time curve of the sum of all conductor currents flowing through it. Its output signal is proportional to the residual current, which flows back to the earthing point of the supply mains via the protective earth conductor in the case of an insulation fault or via the earth. From this signal the residual current level is evaluated by the measuring unit of the analysis system and passed on for display on the connected PC. 4. DRCA?1-SW analysis software: The DRCA 1-SW analysis software provides a range of functions for displaying and evaluating the measured values.

Features:
DRCA 1-CT70 bushing transformer: 70 mm inside diameter, suitable for detecting residual currents from 10 Hz to 100 kHz, different internal diameters available for adjustment to the cable to be monitored, robust plastic housing, reverse polarity protected connection socket for measuring cableDRCA 1-MC measuring cable: , cable length 3 m, reverse polarity protection through plug/socket arrangementDRCA?1 measuring unit: , suitable for detecting residual currents from 10 Hz to 100 kHz and an amplitude up to max. 10 A, immunity against DC residual currents up to 3 A with maximum -10% measurement deviation, robust, handy plastic tabletop housing, reverse polarity protected connection socket for measuring cable and USB cable, LED for displaying the operating statusDRCA?1-SW analysis software: , a number of analysis functions, including display of residual current signal curve, analysis of frequency range (Fourier analysis), display of effective values, long-term measurement with measured values stored for later detailed analysis, recording of signals by defining trigger conditions for determining switching processes or sporadically occurring residual currents, intuitive operation, compatible with Windows 7, Windows 8 and Windows 10

Mounting method:
DRCA?1 measuring unit: tabletop unit for setup on level surfaces DRCA 1-CT measuring bushing transformer: The devices are mounted on stable substrata using the supplied mounting brackets, any installation position

Applications:
Measurement in commercial and industrial installations with TN-S and TN-C-S systems, where power electronics equipment is used without galvanic isolation from the mains, e.g. frequency converters, UPS equipment, switching power supplies or high-frequency converters.

Hints:
The measuring bushing transformer should be mounted in such a way that it measures within the immediate vicinity of the RCD in question.