Author Topic: Problem: switch doesn't really switch off [multiple switches, multiple brands]  (Read 1052 times)

Offline rge

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I think I would check the polarity of the receptacles.  With a volt meter or one of those 3-wire receptacle testers, verify the receptacle and house wiring is correct polarity.

Huh?  It's AC, it won't make any difference to connected devices which way round it is.

Polarity testing is purely a safety thing (to protect inexperienced people who assume that the neutral wire is "safe"), and mainly checking the earth connection, which isn't normally relevant for ZWave devices other than being passed through to the appliance.

Offline rge

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Is it possible that the loud tick is the main power contacts operating (open and close) and the soft tick is a control contact operating. The loud tick would prevent you hearing the soft tick. If the main contacts weld shut due to incorrect loads then you could get your stuation.
Just a thought as I do not know how the devices themselves are built.

Almost certainly there is a relay for the mains power, driven by a solid state transistor which may or may not be part of the control chip - two relays is unnecessary, bigger and more expensive.

Offline Slartibartfast

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Is it possible that the loud tick is the main power contacts operating (open and close) and the soft tick is a control contact operating. The loud tick would prevent you hearing the soft tick. If the main contacts weld shut due to incorrect loads then you could get your stuation.
Just a thought as I do not know how the devices themselves are built.

Almost certainly there is a relay for the mains power, driven by a solid state transistor which may or may not be part of the control chip - two relays is unnecessary, bigger and more expensive.
The quiet click could still be the coil of the power relay operating without the contacts moving. Based on the connected loads however the welded contacts should not happen.
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Offline ember1205

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I think I would check the polarity of the receptacles.  With a volt meter or one of those 3-wire receptacle testers, verify the receptacle and house wiring is correct polarity.

Huh?  It's AC, it won't make any difference to connected devices which way round it is.

Polarity testing is purely a safety thing (to protect inexperienced people who assume that the neutral wire is "safe"), and mainly checking the earth connection, which isn't normally relevant for ZWave devices other than being passed through to the appliance.

But what inside of the switch devices is sensitive to power issues? Or, actually leverages a DC conversion of the AC power in the relay? While it -shouldn't- make a difference, that doesn't mean it wont. When it comes to troubleshooting an issue like this (where more than one device is being impacted), things can't be ruled out because they "shouldn't" have an impact. They have to be checked and actually ruled out. The more information available about the exact situation, the better the chances of diagnosing the problem.

Offline sely

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I think I would check the polarity of the receptacles.  With a volt meter or one of those 3-wire receptacle testers, verify the receptacle and house wiring is correct polarity.

Huh?  It's AC, it won't make any difference to connected devices which way round it is.

Polarity testing is purely a safety thing (to protect inexperienced people who assume that the neutral wire is "safe"), and mainly checking the earth connection, which isn't normally relevant for ZWave devices other than being passed through to the appliance.

But what inside of the switch devices is sensitive to power issues? Or, actually leverages a DC conversion of the AC power in the relay? While it -shouldn't- make a difference, that doesn't mean it wont. When it comes to troubleshooting an issue like this (where more than one device is being impacted), things can't be ruled out because they "shouldn't" have an impact. They have to be checked and actually ruled out. The more information available about the exact situation, the better the chances of diagnosing the problem.

I was thinking possible ground fault protection in the z-wave switch.   Then again, i have seen some pretty strange potentials on neutrals and grounds in houses where somebody messed up the wiring.  I guess after the 4 years and 5 different switches I would be thinking outside the box.
« Last Edit: March 09, 2017, 06:13:18 pm by sely »

Offline JohnRob

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Hi,

Given all the symptoms you mentioned I can think of only two scenario's:

  • The contacts of the failing devices are damaged and are sometimes welding.   This can happen due to very high initial currents from some of the older power supplies.  I would think if this is the case and the failing device is still sometimes working, a sharp blow to the switch would likely make it turn off when it is ON in error.
       If this was the case, can you identify a load that all the failed units have used in the past?

  • I don't know how your particular relays operate, if they are the latching kind, the mechanism to turn off might be worn causing the relay to not toggle to the off condition.  This possibility is more likely than one might think.  I have a Leviton appliance module that "clicks" ON then "clicks" OFF.  If I unplug it from the wall when in either condition there is no "click" indicating the relay remains in its current state without power (i.e. a toggling/latching relay).
    Are your switches "switched" often?