Our SRC2000 and SRC3000 or RLS2000 and RLS3000 thyristor stacks are very suitable for higher power building heating systems, and typically find application in larger commercial, hotel and industrial installations. They are available with standard 0-10V control input to interface to BMS systems, and operate in burst fire mode which is used almost exclusively in the heating and ventilating industry due to its freedom from problems associated with the generation of harmonics and radio frequency interference. In 3-phase applications we recommend the use of our SRC2000 series or RLS2000 with 2-leg control and 3-wire connection of the load, thus avoiding any neutral currents.

It is important when designing a high power installation to consider the effects of voltage flicker on the supply to other equipment, caused by burst fire control. The eye is very sensitive to lighting flicker and a voltage fluctuation as small as 1% can cause noticeable flicker, particularly where lighting is close, for example a reading lamp, on a machine or on a restaurant table. Our LSC2 load sequencing controller is the solution to this problem. It enables control of a large heating bundle in a single air handler to be split into a number of smaller stages so that supply disturbance caused by switching of any one stage is considerably reduced when compared to switching the total load.

Applicable product information is available from our products pages