30A split-core current transformer
€239.20
The AC current sensor for up to 30 A – without cutting the cable
The HW group 30A AC Current probe 1W-UNI 2 is a sensor for the indirect, single-phase measurement of alternating current (AC) up to 30 A without the need to cut the cable. The split-core current transformer can be opened to insert a conductor and is suitable for monitoring the power consumption of racks, BTS stations or server rooms.
The sensor consists of a clamp-on current transformer (“CLAMP METER”) and a 1-Wire converter unit. It can be connected to devices of the Poseidon and Ares families and, together with a Poseidon unit, serves as an early-warning system against overload of the power supply or individual lines.
Indirect AC current measurement up to 30 A
The sensor provides a measured value of 0–30 A AC and is connected to the respective monitoring device via the 1-Wire-UNI bus.
Current range 0–30 A AC
Measurement accuracy 2 %, display resolution 0.1 A, 16-bit A/D converter.
Measurement without interrupting the cable
The hinged clamp core is placed around the phase (L) or neutral (N) conductor – the cable does not need to be cut.
Galvanic isolation
The 1-Wire-UNI bus is electrically isolated from the measured circuit; the maximum measured voltage is 400 V.
2× RJ11 (1-Wire UNI)
Two RJ11 connectors on the converter allow further 1-Wire sensors to be daisy-chained on the same bus.
Bus-powered
Supplied with 5 V (approx. 10 mA) directly via the 1-Wire-UNI bus; a separate power supply is not required.
8 calibration points & unit converter
The sensor can be calibrated at 8 points and features a unit converter.
What is included in the box
The 30A AC Current probe 1W-UNI 2 is a product without variants and is supplied as a complete set.
- Split-core clamp-on current transformer (“CLAMP METER”)
- 1-Wire-UNI converter
- Printed user manual
How the 30A AC Current probe 1W-UNI 2 is constructed
The converter measures approximately 26 × 29 × 42 mm (W×H×D) and weighs about 177 g together with the transformer, with protection class IP33. The sensor is intended for SoHo and IT environments and can be placed on a table or mounted on a wall. Operating conditions: −15 °C to +50 °C at 0–80 % RH (storage: −30 °C to +60 °C, 5–95 % RH).
Split-core clamp-on current transformer
The transformer has a hinged, lockable core. To measure, unlock the core, insert a single current-carrying conductor, close the core again and engage the lock.
Double-insulated connecting cable (1 m)
Transformer and converter are connected by a double-insulated 1 m cable. The length is fixed and cannot be extended.
1-Wire-UNI converter with 2× RJ11
The converter evaluates the signal from the transformer and provides the measured value on the 1-Wire-UNI bus. Two RJ11 sockets connect it to a compatible Poseidon or Ares device and allow daisy-chaining of additional sensors.
Matched pair
Current transformer and converter are matched to each other and are not interchangeable.
How to correctly attach the transformer
- The clamp-on current transformer is placed around the phase conductor (L) or the neutral conductor (N) that carries the current to be measured
- Only a single current-carrying conductor may be passed through the core – two or more conductors make measurement impossible
- The wire must pass freely through the core and must not be wound around the core
- The wire to be measured must be insulated
Safety note: The wire to be measured must be insulated, the supply cable of the measured device must be double-insulated, and the electrical installation must include a main switch or protective switch as well as overcurrent protection. Installation should only be carried out by qualified personnel.
Technical data
- Current range: 0–30 A AC (single-phase)
- Accuracy: 2 %, display resolution: 0.1 A
- A/D converter: 16-bit resolution
- Maximum measured voltage: 400 V
- Cable length transformer – converter: 1 m (fixed, not extendable)
- Galvanic isolation: yes (bus from measuring circuit)
- Calibration points: 8, unit converter: available
- Number of values supplied: 1
Connection to Poseidon, Ares and other HW group devices
The sensor is connected via the 1-Wire-UNI bus to compatible HW group devices, where it is detected and configured.
- Devices of the Poseidon and Ares families (e.g. Poseidon2, HWg-Ares 12, Ares 12 LTE)
- Other compatible devices: STE2 R2, Perseus, NB-2x1Wire, SD-2x1Wire
- Up to 2 sensors per RJ11 connection, up to 8 sensors on Poseidon 4002
- Provision of measured values via LAN or GSM as well as SNMP or Modbus/TCP
- Alarming by e-mail or SMS when values fall outside the “SafeRange”
- Evaluation and Excel export of data with the free HWg-PDMS software
Commissioning in a few steps
The sensor is detected and configured directly via the connected HW group device.
- Place the converter at the desired location on a table or on the wall
- Open the clamp core of the transformer, insert a single insulated phase (L) or neutral conductor, close the core and lock it
- Connect the converter via RJ11 cable to a compatible Poseidon, Ares or other HW group device
- Allow the sensor to be detected automatically on the connected device and configure it via its web interface
- Set thresholds for overload as well as the desired alarm types (e-mail, SMS)
Why the 30A AC Current probe 1W-UNI 2 is the right choice
Without interrupting the cable
The split-core transformer is simply placed around the conductor.
Galvanically isolated
The 1-Wire bus is isolated from the measuring circuit, up to 400 V.
High resolution
16-bit A/D converter and 0.1 A display resolution.
Early-warning system
Detects overload of the power supply or individual lines.
Compact & bus-powered
Only 26 × 29 × 42 mm in size, no separate power supply needed.
24-month warranty
According to the manufacturer with a 24-month warranty from the date of purchase.
Practical application examples
- Monitoring the power consumption of racks (rack monitoring)
- Server rooms and data centres
- BTS stations and telecommunications installations
- Monitoring individual power lines in industrial applications
- Early warning against overload of the power supply
Practical example: In a server room the clamp-on current transformer is placed around the phase conductor of a rack and the converter is connected to a Poseidon2 device. If the rack’s power consumption exceeds the defined threshold, the device immediately sends an e-mail or SMS so that the load can be redistributed in time before the fuse trips.
Frequently asked questions
What is the HW group 30A AC Current probe 1W-UNI 2 and what is it used for?
The 30A AC Current probe 1W-UNI 2 is a sensor for the indirect, single-phase measurement of alternating current up to 30 A without cutting the cable. It is used to monitor the power consumption of racks, BTS stations and server rooms and serves as an early-warning system against overload.
Does the sensor have different variants?
No, the 30A AC Current probe 1W-UNI 2 is supplied without options as a complete set consisting of clamp-on current transformer, converter and printed user manual.
Does the cable have to be cut for measurement?
No. The split-core current transformer is opened, a single current-carrying conductor is inserted and the core is closed and locked again. The cable remains intact.
Can I pass several conductors through the transformer?
No. If two or more conductors are passed through the core, measurement is not possible. Only a single current-carrying conductor (phase or neutral) may be inserted; the wire must pass freely through the core and must not be wound around it.
Can I extend the cable between transformer and converter or interchange the parts?
No. The length of the 1 m cable between transformer and converter is fixed. In addition, current transformer and converter are matched to each other and are not interchangeable.
Which devices is the sensor compatible with?
The sensor is designed for devices of the Poseidon and Ares families and can also be connected to other HW group devices such as STE2 R2, Perseus, NB-2x1Wire and SD-2x1Wire. Up to 2 sensors are possible per RJ11 connection, up to 8 on the Poseidon 4002.
How is the sensor powered?
The converter is powered directly via the 1-Wire-UNI bus (RJ11) with 5 V (approx. 10 mA) and does not require a separate power supply.
Questions about the 30A AC Current probe 1W-UNI 2?
Our support team in Germany provides free advice on selection, sensing technology and configuration.
Current Range:
- Measuring Range: 0–30A AC
- Measurement Accuracy: 2%
- Display Resolution: 0.1A
- A/D Converter Resolution: 16 Bit
Electrical Specifications:
- Maximum Measuring Voltage: 400V
- Electrical Isolation: 1-Wire UNI bus is electrically isolated from the measuring circuit
- Measuring Method: Indirect AC current measurement (without wire interruption)
- Application: Single-phase measurement
Mechanical Properties:
- Construction: Split-core current transformer
- Cable Connection: Double-insulated cable between transformer and converter
- Cable Length: 1m (not extendable)
- Mounting: Hinged clamp core around the conductor to be measured
Environmental Conditions:
- Operating Temperature: 0°C to 40°C (32°F to 104°F)
- Operating Humidity: RH < 80%
- Storage Temperature: -10°C to +50°C (14°F to 122°F)
- Storage Humidity: RH < 70%
Connection and Communication:
- Interface: 1-Wire UNI (RJ11)
- Components: Clamp current transformer (CLAMP METER) and 1-Wire converter unit
- Calibration: Current transformer and converter are matched and not interchangeable
Applications:
- Monitoring power consumption of racks, BTS, or server rooms
- Early warning system against power supply overload
- Monitoring individual power lines
- Use with Poseidon units
Installation:
- Measurement without wire interruption
- Place clamp core around phase (L) or neutral (N) conductor
- Only one conductor should pass through the core (not multiple)
- Wire must be insulated
- Wire must pass freely through the core (do not wrap around)
Safety Instructions:
- The wire to be measured must be insulated
- Power cable of the measured device must be double-insulated
- The electrical installation must include a main switch or circuit breaker and overcurrent protection
- Complies with EU regulations and industry standards
Related Products:
- Sensor 4-20mA 1W-UNI: 0–20mA DC sensor
- Sensor 0-20mA 1W-UNI: 4–20mA DC sensor (with sensor power supply)
- Sensor 60V 1W-UNI v2: 0–60V DC sensor
- 100A DC Current probe 1W-UNI: 0–60V DC sensor
Scope of Delivery:
- Split-core clamp current transformer
- 1-Wire UNI converter
- Printed user manual
Monitoring devices
Other available sensors
Extension units
Accessories
Mounting Plate D Bracket for Ares and Poseidon2 Operating environment: -3°C - 85°C / 0%RH - 100%RH Storage environment: -30°C - 60°C / 5%RH - 95%RH Dimensions: 74 x 6 x 120 (W x H x D) / 58g Warranty: 24 months Wall mounting plate for Ares, Poseidon2 3266/68 and other products.
DB9 LapLink Cable 2m A LapLink cable (also known as Lablink or null-printer cable) is a cable used to connect two computers directly via a cable connection. Housing: Plastic Type: Cable
DIN-Rail Box Set A mounting kit for installing HW-group devices on a DIN rail. Applications and Use: Mounting kit for installing HW-group devices with metal housing on a DIN rail. Operating environment: -30°C - 85°C / 0%RH - 100%RH Storage environment: -30°C - 60°C / 5%RH - 95%RH Dimensions: 45 x 11 x 105 (W x H x D) / 22g
Mounting Kit Screw set for mechanical mounting Applications and Use: Screw set for mechanical fastening
Mounting Plate E- 1U Rack (cabinet) mounting plate, 1U mounting for HW-group Ares and Poseidon2 devices Operating environment: -30°C - 85°C / 0%RH - 100%RH Storage environment: -30°C - 60°C / 5%RH - 95%RH Dimensions: 127 x 45 x 94 (W x H x D) / 137g Warranty: 24 months Rack (cabinet) mounting plate, 1U mounting for HW-group Ares, Poseidon2 3266/3268 and other products.
Mounting Plate L DIN Rail DIN rail mounting plate for Ares, Poseidon2 3268, and other products. Features: Metal housing Wall mounting Applications and Use: Profiles for metal-encapsulated HWg devices for wall mounting. Dimensions: 150 x 120 x 45 (W x H x D) / 65g Warranty: 24 months
Mounting Kit for Poseidon2 4002 and HWg-SMS-GW3 Applications and Use: Mounting kit for Poseidon2 4002 and HWg-SMS-GW3 Operating environment: -30°C - 85°C / 0%RH - 100%RH Storage environment: -30°C - 60°C / 5%RH - 95%RH Dimensions: 136 x 45 x 16 (W x H x D) / 165g Warranty: 24 months
Rack Shelf 1U A versatile solution for easy mounting of HW-group devices in 1U racks. Operating environment: -30°C - 85°C / 0%RH - 100%RH Storage environment: -30°C - 60°C / 5%RH - 95%RH Dimensions: 485 x 44 x 104 (W x H x D) / 597g Warranty: 24 months Housing: Metal Type: Wall mounting This shelf makes it easy to use devices in racks. You can even combine different 1U products and sensors.
Software
Manufacturer information:
HW group s. r. o.
Rumunská 26
Prague, 120 00
Czech Republic
Phone: +420 222 511 918
Email: sales@hwg.cz
Responsible person:
Didactum® Security GmbH
Im Mühlenfeld 4
48163 Münster
Deutschland
Fon:
(+49) 250 19 71 63 54 / (+49) 171 33 11 577
Email: info@didactum-security.de
