The FR4 module is designed to drive up to four three-speed fans in parallel from a single thermostat or room controller. Individual relays with independent contacts are provided for the Three speeds of a typical fan-coil unit. This assures independent operation of the fans for a longer life expectancy.

Additional terminals are provided to drive also heating and cooling valves on all four fan-coil units in parallel.

Benefits of FR 4

Drive of upto 4 fan-coil units from a single thermostat or room controller

Multiplexing of both fan fan speed and valve control


3 Speed fan control

Fuse connection


Power connection for next unit

Power supply connection for thermostat


Ontrol Niagara Day

A Partner Event in Istanbul on October 3rd!

A day filled with technical insights and business sessions. In addition to engaging presentations from Ontrol, several leading companies from the sector will contribute,  sharing their expertise on unique Niagara projects.

Tridium EMEA Managing Director Paul Price and Regional Director Toney Varghese will also be joining as guest speakers, bringing their wealth of knowledge and insights to the event. Stay tuned for more details about the event.