Continuous partial discharge monitoring across multiple cabinets at once
Partial discharge detection
APD-ANNUNCIATOR
Partial discharge alarm system for switchgear cabinets
Description and advantages
The APD-ANNUNCIATOR remotely detects partial discharge activity inside energised cabinets, combining transient earth voltage (TEV), acoustic and high-frequency current sensors with an analysis module that raises a local and remote alarm before an insulation fault damages the switchgear equipment.
Simultaneous detection with several sensor technologies
The module combines TEV detection with contact or airborne acoustic detection, and also accepts high-frequency current sensors to compare technologies and reduce false positives.
Simple installation without interrupting service
Sensors are held magnetically on the cabinet surface or mounted on a DIN rail, with no need to disconnect the installation or drill the enclosure, with no supply outage.
Cascaded monitoring of several cabinets
Several modules can be daisy-chained using standard Ethernet cable, carrying data and power together, monitoring numerous distribution cabinets with minimal cabling.
Configurable local and remote alarm
Each channel accepts a user-defined threshold, with a led indicator and remote alerting via SCADA, web interface, SMS or e-mail.
Applications and operation
Applications
- Continuous partial discharge monitoring in medium-voltage cells and in-service switchgear cabinets.
- Early detection of insulation faults in dry-type transformers and ring main units (RMUs).
- Integration with SCADA systems for trend monitoring and remote alarm generation.
- Substation installations, field applications and remote sites with limited access.
Operation
Alarm levels and zones
Each acoustic and high-frequency channel accepts an independent alarm threshold, set by the user according to the monitored zone of the cabinet, so the sensitivity level can be adjusted to the type of installation and to the ambient noise of each site.
Visual and audible signalling
Detection of a partial discharge immediately activates a local led indicator and a dedicated hardware output; the alert is also sent remotely via SCADA, web interface, SMS or e-mail, according to each channel's configuration.
Installation in cells or outdoors
The module is mounted on a DIN rail inside the cell or held with magnets on any metallic surface, including outdoor installation in substations, thanks to IP65 protection with the dust boots fitted.
Power supply and cabling
Power and data transmission between modules are carried over standard Ethernet cable, allowing several units to be daisy-chained with minimal cabling and bringing monitoring to numerous distribution cabinets at the same time.
Accessories and options
Combined TEV and contact acoustic sensor
Held directly on the metallic surface of the cabinet by magnets; combines transient earth voltage detection and contact acoustic detection in a single probe, with an SMA connector.
Combined TEV and airborne acoustic sensor
Same TEV detection technology, with airborne acoustic pick-up through an adjustable flexible arm; also available in a version designed for installation inside the metallic cabinet.
High-frequency current clamps (20 mm and 60 mm)
Clamp-type sensors with a quick-latch system and IP66 protection, for detecting partial discharge activity through the earth conductor, in two opening sizes depending on cable diameter.
Combined TEV and acoustic sensor, two views
Portable partial discharge tester
Battery-operated functional test unit that verifies the integrity and response of the installed sensors before or during maintenance.
Cloud-based remote access solution
Centralised alarm management, data analysis and record export from a web interface, with cellular communication for installations without a fixed network available.
| APD-ANNUNCIATOR — TECHNICAL SPECIFICATIONS |
|---|
| Installation DIN rail or magnetic mounting |
| Power supply 9 to 24 VDC; 1.2 W max. |
| Acoustic channels 3 |
| Acoustic bandwidth 30 kHz to 88 kHz |
| Acoustic dynamic range 40 dB |
| High-frequency channels (TEV/HF) 3 |
| High-frequency bandwidth 10 MHz to 1.0 GHz |
| High-frequency dynamic range 40 dB |
| Operating temperature -30°C to 50°C |
| Alarm threshold Independently configurable per channel |
| Alarm reporting Local led and hardware output; SCADA, web interface, SMS and e-mail |
| Noise mitigation Algorithm based on amplitude and pulse repetition rate |
| Connectivity Modbus RTU (remote access) and USB (PC connection) |
| Protection rating IP65 with dust boots installed |
| Dimensions 201 x 87 x 53 mm |
| Weight 0.51 kg |
| Approval CE |
Specifications subject to change without notice.
The cellular modem for remote alerting is an optional accessory.