Shelly EM with 120A clamp not reading correct power

    I'm trying to monitor the status of my dryer. My current attempt is with a Shelly EM but I'm having some trouble. I am using a 120A Shelly clamp around the only electric wire going into the dryer. When I initially turn on the dryer it is reading around 8-9 Watts. But when the heating element is off the Watts drop to 0 despite the dryer still running. I have tried clamping other things around the house like my laptop charger, playstation, etc. never read any Watts. I'm wondering if something is calibrated incorrectly or if there's something I need to do make it more sensitive? I have tried two separate Shelly clamps and get the same behavior with both.

    Welcome to the forum!

    Do you have experience with measuring electrical values and do you possess a multimeter? If so, you should measure the resistance between pins P1+ and P1- of the Shelly EM with NO POWER and NO CURRENT CLAMP connected. You should read 10 Ω. If not, you have tightened the screws with too much torque which causes to break the current path.

    Second question: Normally, a 50A clamp is delivered with Shelly EM. Despite a 120A clamp is even suitable, did you strip the insulation of the wires thoroughly?

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