Profile: National Energy Control Corporation specializes in providing HVAC pneumatic, electric and BAS controls. We offer complete assortment of control valves for commercial and industrial applications. Our products include control cabinets & enclosures, bulb controllers, pneumatic temperature controllers, pneumatic receiver controllers, electric step controllers, and heat exchangers. R850V series low voltage step controller is designed for cost effective, precise modulation of multi-stage control applications. A common application is a multi-step electric duct heater. An integrated vernier control output will give a precise full modulation of the load from 0 to 100% of the total capacity.