The MX4428/F4000 Loop Booster overcomes problems such as Responder loop voltage drop and excessive loop length that would otherwise necessitiate a restriction in responders or the use of thicker loop cable. By providing additional power supply capacity to an MX4428/F4000 loop, the Loop Booster is a practical and cost-effective means of overcoming these problems, thus enabling extension of the loop length, additional Responders, or smaller cable size to be used. In fact, one loop Booster will allow three times the loop current, loop length, or 1/3 the cable resistance. The use of Loop Boosters in an MX4428/F4000 system completely overcomes loop voltage drop as a practical limit to system size and allows a loop to be extended until the 127 Responder limit is reached.
The Loop Booster contains its own batteries and charger and when placed in the loop, provides power to a section of the loop and monitors the other. If the voltage on the monitored side falls below 17.0V then the Loop Booster supplies power to this leg as well.
It checks at regular intervals to see if the normally monitored leg can self-establish a voltage of greater than 17.0V.
The Loop Booster has an ADR and RRM built into it allowing fault and control signals to be conveyed to and from the FIP via the Loop communications. The Loop Booster is able to perform a local battery test and to energise the power supply for the monitored
leg of the loop. It can transmit signals to the FIP (e.g. battery test fail, battery low, battery fail and/or charger fault) as well as a monitored leg voltage fail. Remote activation of the battery test and loop relay can be carried out at the FIP by using an ACZ and suitable output logic equations.