Inverters And the Importance Of a Fail-Safe Fire Mode

Power supplies for life-safety systems are derived from frequency inverters in order to vary the speed of the motor, and should always be equipped with a fail-safe fire mode. This fire mode should effectively disable the motor protection function to enable, if necessary, the inverter/motor to run to destruction.

Where inverter control is used and a standby fan is provided, a separate inverter should be provided for the standby fan. And, when necessary, to maintain the operation of the critical life safety equipment, the inverter should always be equipped with a bypass.

If the life-safety ventilation system is required to have pre-determined multiple speeds in fire mode, in order to perform the required duty, each speed should be separately hard-wired and initiated from the individual fire alarm interface modules.

Taking from the above, paraphrased from bs 7346-8 standards, demonstrates an essential reason to specify EMTECT, the only fully-compliant, combined, connected safety control system. The EMTECT system can be used to control the speed of fans in a fire condition, if it is required to do so, to fulfil the requirements of the project specification.

Granted, it is not the only system to be able to perform this function, but it is the only system that is able to comply with the requirement of triggering the speeds directly from the fire alarm interfaces. Why? Most smoke control systems are essentially building management systems and not fire alarm systems (to be a fire alarm system, the products must be certified to en 54). EMTECT’s en 54-certified equipment is capable of fulfilling the requirements of speed controlling fans.

Without compromise, full adherence to compliance is one of the most important reasons to choose any system. EMTECT is more effective in protecting lives for this reason.