Results 1 to 3 of 3

Thread: Should water level sensor be NO or NC when level high?

  1. #1
    New User
    Join Date
    Mar 2017
    Location
    Toronto Canada
    Posts
    7

    Should water level sensor be NO or NC when level high?

    This is for an automatic water change system, using an apex and breakout box.

    My current thinking is that when the water level reaches the top of the tank my sensor should open (or have no current conducting through the leads). This way if there is ever a cord accidentally cut or connection comes loose the tank will not overflow, also two sensors wired in series would give me extra protection.
    However if there was ever a short circuit this would cause the tank to overfill.

    Which is best? Which is more likely...a short or a break?

    Or maybe I should have one of each...one NC and one NO (but that would use up 2 inputs and also require more complex programming)

    Thanks
    Andrew

  2. #2
    Control Freak In Training
    Join Date
    Dec 2016
    Location
    West Unity, OH
    Posts
    133
    2 separate inputs running a virtual outlet and one of each polarity seems the safest way to me.

  3. #3
    Regular Vistor
    Join Date
    Oct 2015
    Location
    central
    Posts
    37
    I work in the laser show industry and we use Estops on all of our systems. All of our estops are designed that when the circuit is closed the laser is enabled. This is a major safety requirement in US laser law as its easier to detect a problem like a cut cable, cable not plugged in, etc as you cant even start your laser until the circuit is made right. The likely hood of a bad cable or a cut is greater than a short as with a short you have to assume two things go wrong as opposed to one (cable gets cut/disconnected and then shorts with the other cable on the same side of the detecting side of the circuit as apposed to just the cable getting disconnected). You can mitigate a lot of short issues too by using proper solder techniques and heat shrink over solder joints. What if the circuit fails closed? Well in our situation we test this before each show, mind you our gear travels all of the world and gets beat up, but you can implement a similar check on your tank by just activating the float once a week or so.

    so, To long/didn't read: go normally closed and use open to detect that emergency situation.

Similar Threads

  1. Sump high level sensor
    By dbdisok in forum Pre-Sales Questions
    Replies: 4
    Last Post: 02-08-2019, 17:14
  2. Help! Float with for high sump water level
    By gwafisher in forum Misc Apex Usage & Programming
    Replies: 3
    Last Post: 10-26-2018, 14:24
  3. Help! ATK Problems - Module thinks water level is too high even when out of water
    By .z. in forum Fluid Monitoring Module (FMM), FMK, ATK, LDK, and FMM Accessories
    Replies: 3
    Last Post: 03-15-2018, 17:44
  4. Help! High level sensor and feed A
    By IBroughtPopcorn in forum Misc Apex Usage & Programming
    Replies: 7
    Last Post: 04-23-2017, 12:26
  5. Help! High level sensor and feed A
    By IBroughtPopcorn in forum APEX Fusion
    Replies: 0
    Last Post: 04-22-2017, 12:51

Bookmarks

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •