Mypin ta4 question...

[todd morrill]

I have a mypin ta4. The setpoint is above the current temp. The out1 led is lit. I have a voltmeter on pins 3-4 and i am getting no output.... 0 volts, I thought the out1 led meant that that the relay is getting triggered with 5+ volts? Where am I wrong here?

 

[dward51]

Does the process LED come one when you move the set point over ambient temp?  It should also go out if you lower the set point below ambient.  If it is doing this, I would check the configuration and use a load (SSR) on the mypin. Remember a SSR is not like a true analog relay (plain old switch).  There is also a DC SSR inside the mypin for the output.  SSR's generally need to have a load on them to work and see voltage with a meter.  The resistance of the meter is too low to work as the load.  If you hook up your SSR and both the process LED on the mypin and the indicator LED on the SSR come on, then it is probably working.  I would then apply a 120v source and load to the load side of the SSR and test for switching.  I know the usual 25amp SSR's will not "read" like an analog relay even when triggered by the 5v DC trigger voltage.  Those absolutely must have a load on them for the internal SSR circuitry to work.