WhoshouldIsee Tracks
Skip to content

Alarm Isolation

Hot site isolation of alarms on high and medium voltage plants

The Alarm Isolation Unit (AIU) is a 6-channel alarm isolator unit for hot site isolation of alarms on high- and medium-voltage plants. The isolator is intended to isolate DC alarm contacts on hot equipment via field wiring with the electronic inputs of monitoring equipment (SCADA, PLC).

Potentially under fault or flashover conditions, the field sensing contacts can be raised to many thousands of volts above ground potential, which would damage low-voltage monitoring equipment.

The alarm isolator unit is mains powered with a nominal 50V DC feed to remote alarm contacts via field wiring. These contacts, in turn, activate the isolated relays in the alarm isolator. Up to six isolator relays can be fitted to the DIN rail in the unit and easily replaced if required. The unit will operate on field wiring up to a maximum loop resistance of 1000 ohms.

Kenton Line Isolation 202A
Alarm Isolation Unit (AIU)

Key Take Aways


up to 6 independant channels.


Low power device.


for SCADA interfaces from high field ESD

High Impedance

Sense loop up to 1000 ohms with loop indicators.


AIU Typical Application Diagram e1502269758545
Typical Alarm Isolation Unit Applicaion

Quick Specs

  • Switching Current: 0.25A
  • Switching Power: 5VA max
  • Switching Voltage: 175V max AC/DC
  • Contact Resistance: 100m?
  • Maximum Release Time: 1mS
  • Operating Time Typical: 0.7mS
  • Mechanical Life: 103 operations
  • Must Operate: >35V
  • Must Release: <10V
  • Coil Current: 20mA max
  • Isolation: 15,000 V RMS
  • Size W x D x H: 280 x 220 x 180
  • Power: 85 to 264 VRMS

Get in touch to talk about your project

We can help!

Our expert team are waiting for your call to assist!

Your Project

Whether you are at the beginning or ready to specify your project requirements we are ready to take your call.

The way forward

Every project is different, our expert team adapts and works with you towards your solution.

Search The Kenton Group