Relay not functioning?

[kevin f October 14, 2019 at 4:37 am Post count: 0]

#36762 Reply |

Hello – I purchased this thermostat controller on a amazon (
https://www.amazon.com/gp/product/B07GQPT9VG/ref=ppx_yo_dt_b_asin_title_o07_s00?ie=UTF8&psc=1). I was able to successfully wire the unit and program it, but the relay does not appear to work. The light goes on and the screen shows “out” but I am not getting any power from the relay outputs (I’ve tested this with an LED light and then finally a voltage meter.) I am power the unit from my RVs 12v system and my meter is showing its getting the full 13.4v. Could it be a faulty unit or is something else going on?

My goal is to use it to engage this small heating pad (https://www.amazon.com/gp/product/B01MTAKZGV/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1).

 
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[kevin f October 14, 2019 at 6:31 am Post count: 0]

#36763 Reply |

Regarding my earlier message….here is how I am wiring the unit (top to bottom):

top terminal =  positive source power from 12v system;

second terminal=  ground

third terminal = positive from unit I am trying to power with thermostat

fourth = negative

from unit I am trying to power with thermostat

[DrokKeymaster October 14, 2019 at 7:30 am Post count: 2971]

#36765 Reply |

Hello kevin f,

As per your description, it seems you only connect power supply for relay.

Please kindly notice that relay doesn’t offer power for load.  You can connect another power supply for load or just use the same power supply, as shown below.

[Kevin f October 14, 2019 at 6:28 pm Post count: 0]

#36770 Reply |

Thank you for your reply. Pardon my ignorance. I am having trouble understanding how the relay will shut the device on and off in your schematic. Let’s say I use the same power supply, as shown your diagram, can you bet specific as to how each wire connects (which terminal)?

1) Positive wire that is the power source for thermostat controller — which terminal?

2) Negative/ground wire for power source for thermostat controller — which terminal?

3)  Positive wire for the device I want to control — which terminal?

4) Negative, ground for the device I want to control — which terminal?

I can also use the USB to power the thermostat controller, if that is easier.

 

 

I am assuming load = the device itself (positive and negative). What is being connected in the middle two screws?

[Kevin f October 14, 2019 at 8:43 pm Post count: 0]

#36771 Reply |

OK. I think I see now. Going from left to right on the terminals — first terminal source power, second and third negative/ground, and the fourth is power to the device I want to control (turn on and off). The device itself is grounded on its end. The thermostat controller is simply making the connection between the first and fourth terminals. The center terminals (2 and 3) ground the controller itself (seems odd that both are needed).

[DrokKeymaster October 15, 2019 at 2:44 am Post count: 2971]

#36772 Reply |

Hello Kevin f,

There may be still some misunderstanding.  The third port is not  always negative. And there are no inner connection between the first and fourth terminals.

If it is hard to get through the first wiring diagram , you can  refer to the second one, that should be more easy to understand how the terminals work.

It is not necessary to distinguish the polarity for thrid terminal and the last terminal. Conversely, you can also connect power positive to third terminal and negative to the last terminal.

It doesn’t matter how you connect power supply to these two terminals, they  just work as a switch, which can control the power to load.

Best regards.

[kevin f October 16, 2019 at 2:24 am Post count: 0]

#36780 Reply |

Got it. Working now.

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