how do you add a switch to an industrial blower?
there is a roughing pump and a blower.how can i add a switch to the blower, since it turns on automatically after the pump brings it down to certain microns. do i put a NC SWITCH OR NO SWITCH? and do i just put my switch so it cuts the 110v on the coil. how would a normally close switch work in this circuit and how would a normally open switch work in this circuit.
note(6 years exp) but motor control is a different world.
- 1 decade agoFavorite Answer
NO and NC switches refer to a switch that is spring loaded and returns itself to a state that is called normal. Normally closed state contacts of a relay are the ones that are closed with no voltage applied to the coil.
If you put a NO switch in line with the coil as you suggest it will not run unless you are there to hold the switch in its ON state.
If you put a NC switch in, the pump will run as normal and stop when you hold the switch in its OFF state.
You may need a simple toggle switch that will remain in the position you last left it. In any case select a switch of the proper current and voltage rating.
- javaLv 41 decade ago
Sounds like you need to incorporate a "timer" to switch off the blower after a preset time once the roughing pump has either started or stopped. You need to think on these lines and talk it over with an Electrician. For example If its when the roughing motor is "started" you want the blower to run for a short time only
in this case choose an "Agastat timer" to cover the time you want i.e. zero to 10 minutes.(type: "delay on pick up" of the timer coil). Rated at 110V, 10 amp contact rating.
You will need to feed a 110V supply via the motor starter of the roughing pump NO contact. to the coil of the timer.
Then from a NO conact of the timer feed the 110V supply to the Blower motor starter coil.
Now when the roughing motor starts the coil of the timer energises and the blower motor will run and stop once the timer has timed out.
Hope this puts you on the right track.