Moudulating solid state current valves

[Troyevol]

can you guys anwser a question , I have moudulating solid state current valves on a VAV pnuematic system it has electric make up heat coils , what do the current valves do and where can I find info about so I can understand what they do ????

thanks in advance :)

[pacmike]

replace with updated controls

[beenthere]

Made this its own thread, and moved it to commercial.