Results 1 to 5 of 5

Thread: Turning heater off if watt draw is too much

  1. #1
    Regular Vistor
    Join Date
    Apr 2018
    Location
    US, Eastern Time
    Posts
    15

    Turning heater off if watt draw is too much

    I am new to APEX and I am wondering if there is a way, in addition to temperature, to turn off the heater outlet if the heater is drawing more watts than it is rating. For example, I use a 300 watt heater and if it were to draw more than the rated 300 watts the outlet would turn off. In a way this would allow the outlet to function almost like a gfci outlet.

    TIA

  2. #2
    Frequent Visitor rkpetersen's Avatar
    Join Date
    Jun 2017
    Location
    Near Seattle
    Posts
    940
    Yes. To do this exact thing, you would insert this line into your heater code:

    If Output Heater Watts > 300 Then OFF

    However, there are better ways to code for potential heater failure. Instead of increased wattage, use increased amperage and code for a cutoff of 150% of the normal max operating amps (found from the Input Logs page in Fusion.) Then, also code for decreased heater wattage, with a cutoff of 50% of your normal operating watts (you can just use 300/2=150, or use actual numbers from the Input Logs page again.) These two lines will cover detecting high impedance faults, arcing partial contact faults, and open heater contacts when the Apex wants it to be on.

    Putting these lines into your heater code will control the heater directly. However, some of these detections will only be of real value if you also set up alerts to notify you when these conditions occur. You can do this either from the Inputs page in Fusion or coded directly into your email/text alarm tile.

    Here is a more detailed discussion of coding for a heater failure mode (including use of virtual outlets.) In particular, see zombie's posts for his recommendations and the rationale for them.

    https://forum.neptunesystems.com/sho...Heater-Program

  3. #3
    Frequent Contributor zombie's Avatar
    Join Date
    Dec 2013
    Location
    Denver, CO
    Posts
    13,176
    I agree 100%. The reason for those suggestions in case you don't want to read the entire thread is that wattage can actually go down when a device short circuits depending on how the utility wiring upstream from you is laid out but current or amps will always go up. Short detection is better done with amps and open circuit detection is slightly better done with watts (only because it has more granularity especially on smaller devices) but amps are what really matters for all of it.

    You might be an engineer if...You have no life and can prove it mathematically.

  4. #4
    Regular Vistor
    Join Date
    Apr 2018
    Location
    US, Eastern Time
    Posts
    15
    Quote Originally Posted by zombie View Post
    I agree 100%. The reason for those suggestions in case you don't want to read the entire thread is that wattage can actually go down when a device short circuits depending on how the utility wiring upstream from you is laid out but current or amps will always go up. Short detection is better done with amps and open circuit detection is slightly better done with watts (only because it has more granularity especially on smaller devices) but amps are what really matters for all of it.

    You might be an engineer if...You have no life and can prove it mathematically.
    How does this look?

    Heater code...

    Fallback OFF
    If Tmp < 78.0 Then ON
    If Tmp > 79.0 Then OFF
    If Tmp < 70.0 Then OFF
    If Output HeaterFail = ON Then OFF
    If Output Maintenance = ON Then OFF


    If heater fails...

    Set OFF
    If Output Heater Watts < 150 Then ON
    If Output Heater Amps > 2.5 Then ON
    Defer 000:10 Then ON
    Defer 000:10 Then OFF
    When On > 000:05 Then ON


    How about UV Codes...

    Fallback OFF
    Set ON
    If Tmp > 83.0 Then OFF
    If Output Maintenance = ON Then OFF
    If Output UVFail = ON Then OFF



    Set OFF
    If Output UV Watts < 20 Then ON
    If Output UV Amps > 0.5 Then ON
    Defer 000:10 Then ON
    Defer 000:10 Then OFF
    When On > 000:05 Then ON

    Sent from my SM-G955U using Tapatalk

  5. #5
    Frequent Contributor zombie's Avatar
    Join Date
    Dec 2013
    Location
    Denver, CO
    Posts
    13,176
    That is put together correctly, but for heaters I only like to lock out for shorts. For open circuits (typically due to thermostat opening when it shouldn't) I like to use a self resetting block and be alerted like this.

    Heat1Stat
    Set OFF
    If Output Heatername watts < 150 Then ON
    Defer 000:10 Then ON
    Defer 060:00 Then OFF

    You might be an engineer if...You have no life and can prove it mathematically.

Similar Threads

  1. 800 watt heater
    By Zaireguy in forum EnergyBars 832 / 632 / 8 / 6 / 4
    Replies: 6
    Last Post: 03-15-2018, 02:28
  2. Eb832 Handle 1000 watt heater?
    By robbous in forum EnergyBars 832 / 632 / 8 / 6 / 4
    Replies: 5
    Last Post: 10-22-2017, 20:32
  3. Eb832 Handle 1000 watt heater?
    By robbous in forum A2 Apex/ApexEL and A3 Apex Pro/Apex/Apex Jr
    Replies: 3
    Last Post: 10-19-2017, 20:47
  4. Unable to get power to 250 watt heater
    By lou_raffael in forum EnergyBars 832 / 632 / 8 / 6 / 4
    Replies: 2
    Last Post: 03-11-2017, 17:36
  5. Question: Finnex 300 watt heater
    By Pmc75 in forum Apex Programming for Heaters and Chillers
    Replies: 3
    Last Post: 11-01-2016, 20:33

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
  •