Video: APD-ANNUNCIATOR – Product

Video transcript

Why switchgear needs a partial discharge alarm that never sleeps, and how the APD-ANNUNCIATOR provides it, what it senses, how it is installed without an outage, and how the alarm reaches you. Partial discharge is commonly found in aging medium-voltage cable accessories and switchgear. It erodes the insulation slowly, and then a fault takes out the cabinet. The hardest places to watch are secondary substations. There are many of them.

They are spread over a large territory, and nobody is there between visits. The APD-ANNUNCIATOR is an online alarm system. Up to three sensors sit on the cabinet. The module processes their signals, compares each channel with its own threshold, and when there is activity it lights the alarm and passes the same status to the SCADA and to the remote interface. module has three acoustic channels, from 30 to 88 kHz, and three high-frequency channels,

from 10 MHz to 1 GHz, both with 40 dB of dynamic range. It runs on 9 to 24 volts DC and draws 1.2 watts at most. A discharge inside a metal cabinet sends very high-frequency pulses that appear on the outside of the enclosure as transient earth voltages. Surface discharge and corona also make ultrasound. The sensor picks up both at the same spot, and a high-frequency current clamp adds the pulses that return through the earth conductor.

The module is a sturdy three-piece aluminum case. On the front, one green lamp shows that it is powered, and one alarm lamp per sensor input, S1 to S3, shows which channel has detected activity. is a sensor for each case. The contact version sits flat on the panel. The airborne version listens through vents and gaps, and a third one is designed to be fitted inside the cabinet.

For cables, high-frequency clamps with 20 or 60 mm openings, a spring latch, and IP66 protection. Nothing is switched off to fit it. The module clips onto a DIN rail, or holds onto any metal surface with its two magnets. The sensors are magnetic too, so the enclosure is not drilled, and the supply is never interrupted. To watch a whole line of cabinets, modules are daisy-chained.

One standard RJ45 cable runs from module to module and carries both the data and the supply, so a single power source and a single connection to the SCADA serve the whole row. Each channel has its own threshold, set by the user for the zone it watches and the noise of the site. When a channel crosses it, the module lights the channel's lamp, switches a dedicated hardware output, and reports the alarm to the SCADA, the web interface, and by SMS or email.

substation is full of electrical noise, and an alarm that rings every day is soon ignored. The module mitigates high-frequency noise by looking at both the amplitude and the repetition rate of the pulses. And because two technologies watch the same spot, a reading on one can be checked against the other. Through USB, the SCADA, or the web interface, every channel can be followed over time.

The trend shows how the activity evolves against its threshold, and each channel's alarm can be adjusted or enabled from the same screen. For remote sites, there is an optional cellular modem and a cloud-based remote access solution. Configuration, data analysis, alarm management, and the location of every installation are reached from a browser, with password protection, user access management, and encrypted communications. does it fit? The PXDP-II and the APD-LT are portable instruments.

They survey and locate during a visit. The APD-ANNUNCIATOR stays on the cabinet and watches it day and night, so the survey can go where the alarm points. place is medium voltage switchgear and ring main units in service, dry-type transformers, and every substation where a fault would be found too late, field installations, and remote sites with limited access. figures, three acoustic and three high-frequency channels, 9 to 24 volts DC, minus 30 to plus 50 degrees, IP65, and a module of half a kilogram.

Partial discharge detection from Amperis.