Integrated Fire Protection for Modular E-Houses

We recently completed the installation and delivery of our 14th Modular E-House to a mining client in Ghana. We installed the latest fire detection and gas suppression technologies in these Electrical Rooms (E-Houses) with custom integrations into the Mining Fire Control Network.




Modular E-Houses are prefabricated transportable substations, designed to house critical power equipment. Naturally, fire can cause extensive damage to the critical electrical components within an E-House, so early warning smoke detection and immediate shut down of interconnected systems is needed to protect against the risk of irreversible damage and downtime.


THE BACKGROUND


A mining company in Ghana faced the challenge of getting their prefabricated E-Houses fitted with compliant and standardized fire protection systems; before being delivered to their site. As these prefabricated structures were outside of the direct management control of the mine and their EPCM partners, the client was unable to ensure systems that were compatible with their existing site fire control network as well as their stringent quality standards.



Following previous projects, the client knew that the FS Group had the necessary skills and supply chain partners in South Africa and that there would be continuity in service delivery. The construction of the E-House Fire Systems would be supervised by the same team responsible for the final delivery, commissioning, and integration of the systems into the Mining Fire Control Network.


The client expected the FS Group to fit the same fire protection systems to their internationally sourced E-Houses, as the systems they currently have on-site. This was to ensure that the systems were identical, assembled from familiar components, and configured in the same way as their existing systems.


THE SOLUTION


After consultation with the client and construction partners, a standard procedure was discussed which outlined the technical specifications and functional parameters of the fire protection systems for a typical E-House. Equipment that met the client’s expectations and was compatible with existing systems on the mine site was identified during these discussions.


Procedures were formulated around the operation of the fire protection systems, and deeper discussions were required to identify the interaction between the fire protection and the process control systems of the mine. The requirement was to prevent damage to expensive plant equipment and preserve operational continuity of the mine, so the fire protection systems needed to automatically initiate a controlled shut down of various sections of or the entire plant in the event of a confirmed fire. The data acquisition and control systems on the mine site could accommodate several inputs. These ranged from various Fieldbus protocols to simple voltage-free relay contacts. The client required a fire system compatible with these interfaces.


Installation, configuration, PLC interface procedures, documentation requirements, and handover procedures were discussed and agreed on. A comprehensive Standard Procedure and Technical Specification document was then drawn up and submitted to the client for approval.



Equipment fitted into the E-Houses includes:


  • The Edwards EST3 System, the existing technology of choice, was installed as the primary fire control system. The EST3 System was fitted with fiber optic communications components, which allowed integration into the mine’s site-wide fire systems when the completed E-House was delivered to the site

  • The Technoswitch TC3001 Conventional Detection and Gas Control unit was selected to detect the presence of fire and control the suppression gas discharge process

  • Apollo Conventional Point Type Heat and Smoke Detectors were used as general fire detection in the E-House environment

  • A Honeywell VESDA high sensitivity Aspirating Smoke Detector was chosen to provide early warning smoke detection

  • A Brigit Systems HFC227ea (FM200) Gaseous Fire Suppression system was selected as the Fire Suppression system of choice. The system could be deployed as an in-cabinet or total room flooding solution

  • Appropriate warning devices, bells, and re-entrant speakers and strobe lights were installed

  • A custom integration pack was designed and installed into the E-House allowing automated interlocks between the EST3 Control Panel and the E-House electrical and PLC systems. The system is comprised of the following interlocks:

  • Configurable EST3 High Power Relay modules to provide voltage switching capabilities for air handling, lighting, and access control systems. Fresh air make-up systems could be set to recirculate air, lighting systems switched and access control systems put on alert in the event of pre-fire alarm received from early warning detection systems.

  • Configurable EST3 Low Power transistorized switching modules to provide voltage-free contacts for interface into the PLC and video surveillance systems. In the event of pre-fire alarm events, the Video Surveillance operators could be alerted to the alarm and then conduct a video surveillance tour of the affected area to verify the event. In the event of a confirmed fire, shut down procedures of process plant equipment could be initiated from the EST3 system.

  • A Modbus over IP communications server was installed onto the EST3 fire alarm control panel in the Plant Control Room and interfaced directly into the Plant PLC system. This allows the operator to monitor the status of all the fire alarm and detection devices across the entire site.



SUMMARY OF TECHNOLOGIES PER E-HOUSE

  • 1 Fully populated EST3 Control Panel with Audio Source unit

  • 5 EST3 interface and relay modules

  • 4 EST3 High Power fiber transceiver modules for allowing redundant class communication to the other EST3 nodes on the network

  • 1 Advanced Fire TC3001 combination detection and gas control panel

  • 8 – 16 Apollo point type detectors (depending on the size of the structure)

  • 1 VESDA VLF500 with sampling pipe and capillary detection tubes for in-cabinet detection

  • Brigit Systems HFC227ea (FM200) with 15 – 350kg’s of gas (depending on the size of the structure)

  • Battery cabinets containing high-capacity backup batteries for extended operation during power outages.

CONCLUSION


To date, 14 E-House systems have been installed and delivered to the client. Further E-Houses will be constructed and delivered as the mine’s operations expand and other mines are developed.