Maintenance for EN.sus

At the end of October 2019 Application Solutions provided PAVA Services with a sales lead. The lead was for the routine maintenance of the Voice Alarm system at Ensus Ltd.


Ensus, operates one of the largest production plants for bioethanol in Europe. The site in the North East of England has an annual capacity of 400,000 cubic metres of bioethanol. In addition, the site produces 350,000 tonnes of dried protein animal feed (DDGS).

Voice Alarm Maintenance at the Ensus site.
The Ensus Site

The plant uses over one million tonnes of feed wheat per annum, sourced in the UK and Europe. Feed wheat has a higher yield potential, but is lower in quality than Milling wheat. The UK and Europe have historically produced a surplus of feed wheat, and the UK typically exports between 2 and 3 million tonnes each year.

Today, feed wheat production is a highly efficient use of agricultural land, producing almost as much protein per hectare as soy. However, it is capable of converting twice as much solar energy into plant energy, storing the excess as starch which can be converted to biofuel.

Ensus manufactures a high-grade animal feed from the by products, known as stillage, produced during the production of bioethanol. Stillage has been fed to animals in liquid form for centuries. However, when dried, it becomes a storable product known as DDGS (Distillers’ Dried Grains with Solubles). Because it is high in protein, fat content and energy; DDGS is ideal as a high-grade feed for all types of livestock as well as for pets.

The System.

Back to the job in hand…Maintenance.

The system at Ensus dates back to 2007. At the heart of the system is an Application Solutions VAR12 Voice Alarm Router. The VAR12 provides 12 audio input and audio 12 outputs forming a 12 x 12 matrix. In addition the router provides eight digital alarm messages and two background music inputs.

Two microphones connect to the VAR12. The first is a ‘Firemans’ microphone whilst the second is a zoned paging microphone. Both being located in the control room. Two digital alarm messages are installed. The first provides Fire Alarm Evacuation Message whilst the second provides the Toxic Gas Evacuation Message. Connections from the Fire Alarm and Gas Detection systems automatically trigger the two messages.

Ten of the VAR12’s outputs connect to the systems amplifiers; five Jedia JPA4240DPT four channel 240W and two Jedia JPA480DP 480W amplifiers. Each VAR12 output connects to two amplifier channels, thereby providing A & B loudspeaker circuits.

Each amplifier provides individual fault contacts for the following fault conditions:

  • Fuse Failure
  • Power Failure
  • Amplifier Failure
  • Line Surveillance
  • Earth Fault Detection (via an additional module manufacture by TOA)

The VAR12 recieves the fault signals via one of three Digital Input Output (DIO) modules. The VAR12 then displays the reported fault on its LCD display. A common fault output then signals to the Fire Alarm System that a system fault is present.

Maintenance Schedule.

BS5839 Part 8: Code of practice for the design, installation, commissioning and maintenance of voice alarm systems, sets out the maintenace routine.

These tests check the operation of the:

  • Microphones
  • Digital Voice (Alarm) Messages
  • Loudspeakers & Loudspeaker Circuits
  • Fault montoring
  • Power Supplies
  • System Audibility & Intelligibility

Checks are also made to determine if there have been acoustic changes to the site. These could include building modifications, changes of use, etc which may effect the site coverage

Moving Forward.

We identified several faults with the system, however the system was functional and continued to provide good coverage of the site.

Work has now started on clearing these faults.

Read more about Ensus on their website.