Proportional controllers such as the RGC1P series can modulate the heating power from 0% to 100% based on the level of an analog input. The RGC1P can take both an analog voltage (0-10V) as well as an analog current (4-20mA) input. The front selector switch allows the user to select the preferred method of switching. The full cycle switching on RGC1P minimizes EMC disturbance by conducting full voltage cycles with a duty cycle that can be determined by a second selector switch. Other methods of switching such as the more traditional phase angle control are also available.
Two phase proportional controllers such as RGC2P series provide a more cost effective heater switching solution by switching only two poles whereas one of the poles is a pass through. If a finer control on the modulation of 3 phase duct heaters is required, RGC3P series controls all the three poles. The RGC2P...C1 and RGC3P...C1 variants are designed with full cycle switching that allows efficient heat modulation without creating any electro-magnetic (EMC) disturbance. The ratio of the on to off cycles is determined via the front selector switch.