Author Topic: Is this the right way to wire thermostat input / output?  (Read 713 times)

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Offline petrezaTopic starter

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Is this the right way to wire thermostat input / output?
« on: December 17, 2019, 08:54:52 pm »
I have this thermostat that uses one of those finicky universal outputs. The contact is not very good, sparks fly/buzzing sound, see the left top corner of the gray plastic - it has melted. This is with the heater at the lowest setting - 500W.



When I looked at the internal cables that connect the input (jack)--(relay)--(output jack) something struck me as odd - the right input (red) is connected to the left (red) output.
1. Is this how it is supposed to be - mirror image?

When I plug in cables in both input and output:



I get continuity between these two wires:



2. Also, just to confirm - the relay connects/disconnects the blue and the yellow - the red one that goes in the back is just to power the thermostat/relay?
« Last Edit: December 17, 2019, 08:57:19 pm by petreza »
 

Offline GerryR

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Re: Is this the right way to wire thermostat input / output?
« Reply #1 on: December 17, 2019, 11:32:16 pm »
It looks to me that your relay is switching the neutral (Blue) instead of the hot (Red).  From your picture with the meter, the hot and neutral are swapped.  By convention (and the way you have them marked), Red is Hot, Blue is Neutral and Green is Ground.  The relay should be switching the hot, at least that is how it is normally done.
Still learning; good judgment comes from experience, which comes from bad judgment!!
 

Offline Nusa

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Re: Is this the right way to wire thermostat input / output?
« Reply #2 on: December 18, 2019, 01:07:21 am »
So-called universal outlets can't get the polarity right for all countries, because all countries are not consistent. However, IEC inputs ARE consistent in polarity, if not voltage. Assuming, of course, that the IEC input cords are wired correctly, which they occasionally aren't.

So yes, when you're using a US plug, you're getting hot and neutral swapped. Which could be dangerous with some devices. If you're never going to travel internationally with this device, I'd suggest correcting it.
« Last Edit: December 18, 2019, 01:12:12 am by Nusa »
 


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