T915C and L956 Proportional Temperature Controller

T915C and L956 proportional temperature controllers find application in Series 90 control systems and in controlling duct air temperatures, as well as liquid temperatures in tanks and boilers. They have one potentiometer for controlling a single Series 90 motor or relay and an adjustable proportioning range. These units are generally used with Series 90 motorized valves or dampers. A remote-bulb sensing element detects system temperature variations, and by means of a capillary and bellows, operates a wiper over potentiometer windings.