Rack Monitoring & Cabinet Supervision in Server Rooms

Didactum Small AC Current Transformer

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

Product number: DI14033

€89.00

Rack Monitoring / Cabinet Monitoring

In the event of operational disruptions and critical (physical) incidents, precise IT monitoring - such as IT cabinet monitoring, server room monitoring, or rack monitoring - not only enables proactive and targeted action, but also ensures that your data center operates as efficiently as possible, right down to the cabinet level. By using server temperature sensors, server room IT security, and IT environmental monitoring, risks can be identified and minimized at an early stage.

A rack monitoring solution typically includes the following elements:

Environmental monitoring of temperature, humidity, and air circulation (e.g., server room humidity sensor, server temperature sensor)
Access control for the server cabinet (access monitoring / access control)
Power monitoring (power switching)
UPS battery monitoring
Server rack alarm and server room data logger for comprehensive monitoring

Thermal Monitoring of the Rack

For thermal monitoring of IT racks, we offer suitable sensors for temperature and humidity monitoring. Measure and monitor the temperature at the top, middle, and bottom of the IT server cabinet. This allows you to reliably detect issues such as hot spots. We believe that a single temperature measurement point in the IT rack is not sufficient to determine whether the installed network, storage, and server systems are being cooled efficiently. Therefore, temperature sensors should be installed on both the front and rear of the IT cabinet. This allows you to check whether the air supplied to the air inlet of the IT cabinet is sufficiently cool. Installing temperature sensors on the rear of the IT cabinet provides important information about whether the exhaust air temperature is too high. The collected measurement data - such as from a server room data logger - can be used to determine whether the essential cooling air in the server cabinet is being obstructed by network cables, power cables, or similar.

Access Control and Management of IT Racks

In our opinion, physical access to server cabinets in the data center is not sufficiently monitored. It is an open secret that security breaches, sabotage, and data theft can occur directly on-site in the data center or location. Very few cases become public knowledge. By installing an RFID-based swing handle, physical access to the sensitive 19-inch server cabinet can be effectively controlled and managed. At the same time, the lid, side panels, and rear panel of the 19" server cabinet should be protected against unauthorized opening by installing magnetic contact sensors. An infrared sensor for access monitoring informs you whether the server cabinet door is open or closed. Here too, comprehensive server room security helps minimize risks.

Video Surveillance in the Server Room / Data Center

By installing suitable video surveillance cameras in the server room or data center, risks such as tampering, sabotage, or data theft can be reduced.

Editorial Note:

The installation of a video security solution in the data center should be closely coordinated with the works council or staff council and carried out in strict compliance with the German Federal Data Protection Act (BDSG) and current legal requirements. It is well known that a data center requires a very high level of protection, so there should be no obstacles to a works agreement ("A data center/server room is not a social space").

Monitoring Power Consumption of IT Racks (Power Monitoring)

Monitoring the power consumption of 19-inch server cabinets is an important aspect of data center management. By knowing the power consumption of each IT rack, overloads and tripping of circuit breakers can be prevented. The measured power consumption can be used for cost accounting and for measures to increase energy efficiency in the data center (keyword "Green IT"). The UPS system installed in the server cabinet can also be monitored around the clock as part of rack monitoring. Measure and monitor the battery charge status and battery performance of the UPS and receive proactive notifications via SNMP monitoring or SNMP traps, email, or SMS. Automated actions, such as the orderly shutdown of physical or virtual servers in the event of a power failure or battery operation, can also be implemented with the offered rack monitoring solutions.

Notifications and Alarms

The rack monitoring solutions offered support a wide range of notifications and alarms. In addition to support for email and SMS alarms, solutions are also available in the form of phone/mobile calls with individual voice messages. A server rack alarm can thus be triggered individually and reliably.

Integration with Network Monitoring Software and DCIM Solutions

As part of rack monitoring/cabinet monitoring, we rely on the widely used SNMP monitoring network protocol. Physical environmental influences (temperature, humidity, airflow, etc.), errors, and status messages are transmitted via SNMP traps to network monitoring software (including CA UIM, HP OpenView, Nagios, check_MK, OpenNMS, PRTG, Solarwinds, Zabbix) and DCIM software. Using the Snmpget command, sensor data can also be queried remotely via LAN/WAN and monitored directly by the monitoring software.

A modern IT cabinet monitoring system with server temperature sensors, server room humidity sensors, server rack alarm, server room data logger, and comprehensive server room security is the foundation for a reliable, efficient, and secure data center.

Didactum Monitoring

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