Compact Hall Effect Probe for Smaller AC Circuits The Didactum Small AC Current Transformer probe is a simple open-loop Hall effect AC current transducer (open-loop ammeter) in a particularly compact design that measures current on a conductor contactlessly without disconnecting it. The cable to be measured is passed through the opening of the ring-shaped transducer; the probe converts the measured AC current into a proportional 0–5 V DC output signal. This article refers to the AC-50 model with a rated current of 50 A and a measuring range of 0–50 A — ideal for individual circuits, outgoing feeders, and smaller to medium-sized loads. ⚠️ Important note: The Didactum Small AC Current Transformer probe measures the current on the conductor, but it cannot transmit the measurement signal to a monitoring system on its own. You also need the Didactum AC Current Transformer, part no. DI14030-AC, which acts as a transceiver, receives the probe’s 0–5 V signal, and forwards it via an analog port (A1…A8) to the Didactum monitoring system. Without the DI14030-AC, no display, analysis, or alarm notification of the measured values is possible. Design Current Probe Design The current probe consists of a compact ring-shaped transducer head with a pass-through opening and a 3-pin connection terminal. 1 Pass-through opening The cable to be measured is routed through the opening in the ring-shaped compact transducer core. The probe measures the current contactlessly via the magnetic field that is generated. 2 Mounting tabs Two mounting tabs on the housing used to secure the probe with screws and nuts. 3 3-pin connection terminal (pitch 3.81 mm) Three-pin terminal for wiring to the Didactum AC Current Transformer DI14030-AC. Pin assignment: + (+12 V DC supply), G (Ground), M (0–5 V measurement signal). ℹ️ Note on confusion: The AC-50 probe has a 3-pin terminal (+, G, M). The larger K6A model for higher currents uses a 4-pin terminal (G, M, G, +). When connecting, make sure the wires are assigned correctly according to the terminal labeling. Installation Mounting and Connection The current probe and the Didactum AC Current Transformer (DI14030-AC) are installed together. 1 Mount the probe Secure the current probe in a suitable location with screws and nuts. Route the cable to be measured through the probe’s pass-through opening. 2 Wiring to current transformer DI14030-AC Connect the 3 wires of the terminal (+, G, M) to the 3-pin input terminal of the Didactum AC Current Transformer (DI14030-AC) according to the wiring assignment. 3 Connect to the monitoring system Connect the Didactum AC Current Transformer (DI14030-AC) to a free analog port (A1…A8) of the Didactum monitoring system or an 8-port sensor expansion unit using an RJ11 cable. ⚠️ Safety instructions: The regulations applicable to installation in the respective country and the relevant accident prevention regulations must be observed, as well as internal company work, operating, and safety regulations. The specified technical limits, especially insulation voltage and ambient temperature range, must under no circumstances be exceeded. Before installation, check the maximum permissible conductor diameter and the maximum insulation voltage of the probe. Web interface Full Control over Thresholds, Trends, and Automation Via the Didactum AC Current Transformer (DI14030-AC), the probe integrates seamlessly into the Didactum web interface. Individual thresholds (Lower Critical, Lower Warning, Normal, Upper Warning, Upper Critical) for each measurement point Logic schemes for automated actions when limit values are exceeded, e.g. in case of overload Clear, individually configurable dashboard Graphical trend display and continuous logging of measured values Notifications via email, SMS, SNMP trap, and other channels Application examples Use Cases for the Current Probe Monitoring circuits and feeders in electrical distribution panels to detect overloads Monitoring motors, pumps, compressors, and production machines for load changes Automatic alarm notifications when defined current limits are exceeded to prevent equipment damage and power outages Monitoring the power consumption of smaller IT and facility devices in the data center Early detection of wear or defects based on changes in current consumption Complementing existing monitoring environments (Zabbix, PRTG, Nagios) Scope of delivery What Is Included Please check the delivery for completeness upon receipt and report any missing or damaged parts to your supplier immediately. The Didactum AC Current Transformer DI14030-AC is not part of this scope of delivery and must be ordered separately. Didactum Small AC Current Transformer probe AC-50 (50 A)1 piece Self-adhesive label1 piece Screw L18.5 M42 pieces Bolt L14 M42 pieces Nut M3.52 pieces Key benefits Why This Current Probe Is the Right Choice 50 A rated currentMeasuring range 0–50 A for circuits and smaller to medium-sized loads. Compact designEspecially space-saving, ideal for tight control cabinets and distribution panels. Contactless measurementCurrent detection without disconnecting the conductor. High accuracy0.5% accuracy and linearity error. Easy installationMounting via two tabs with screws and nuts. Robust insulationInsulation voltage AC 2.5 kV 50 Hz 1 min for safe operation. Wide operating rangeDesigned for ambient temperatures from -10 °C to +70 °C. Made in EUDeveloped and manufactured in the European Union. FAQ Frequently Asked Questions For which current range is this model suitable? This model (AC-50) has a rated current of 50 A and covers a measuring range of 0–60 Aac. Make sure the maximum expected operating current of the conductor being monitored stays safely within this range. How does this probe differ from the larger K6A probe? The AC-50 probe is more compact and uses a 3-pin terminal (+, G, M), while the K6A probe for higher currents uses a 4-pin terminal (G, M, G, +). Both probes require the Didactum current transformer (AC version) as the transceiver to the monitoring system. Can the current probe be connected directly to the monitoring system? No. The probe outputs a 0–5 V analog signal and absolutely requires the Didactum AC Current Transformer (DI14030-AC) as a transceiver, which transfers this signal to an analog port of the monitoring system. Is the DI14030-AC included in the scope of delivery? No. The Didactum AC Current Transformer DI14030-AC is a separate product and must be ordered additionally if not already available. Does the conductor have to be cut open for installation? No. The current probe measures contactlessly via the magnetic field of the conductor routed through the pass-through opening. Cutting the conductor is not necessary for the measurement itself. Can multiple current probes be used at the same time? Yes. Each circuit to be monitored requires its own AC-50 current probe with its own Didactum AC Current Transformer (DI14030-AC) connected to a free analog port. If the available ports are not sufficient, the number can be expanded using a VT408 expansion unit. Questions about the Didactum Small AC Current Transformer probe? Our support team in Germany will advise you free of charge on selection, installation, and configuration. Contact form (+49) 2501 92 90 160