Circuit design problem

HI, i have designed a control cabinet with 24vdc control circuit. for some reason the control relay burns out. the psu is RS 122-2216 the relay RS 144-1609. the relay is powered on when contacts on a timer are closed. when this occcures the coil on the relay overheats. what have i got wrong? all wiring checks out. 

any help greatly appreciated

Thanks

Can you please share your diagram

  Joined November 19, 2019      4
Tuesday at 08:44 PM

Hi Bilal

i dont have the full diagram here at work so have done a quick basic sketch 

circuit.jpg

  Joined November 12, 2019      2
Tuesday at 04:22 PM

I am confused with your relay part number, in the question you state it is RS 144-1609, but in the circuit diagram you have written RS 145-1602. So which exactly is your relay part number?

Hey I tried searching for your relay part number RS 145-1602 and found this

https://docs.rs-online.com/2277/0900766b81633c5f.pdf

This relay is rated for 24V so yes it should work for you, but make sure the part number is RS 145-1602 because other relays have diferent part number

Capture.PNG

Once you are sure with the relay part number if the heating problem is still there then it should be because of your Load. Note that this relay can only dive 12A at 250VAC. What load are you using and how have you connected it?

And I dont see any short circuit like Jim stated and you wont be needing any resistance for this. Your PSU outputing 24V should be able to drive your 24V relay directly through your timer 

  Joined August 27, 2018      25
Monday at 04:18 PM

Relay burns out because it's a short circuit.  You need a load in series with the relay at a minimum.

  Joined November 18, 2019      8
Monday at 02:06 AM

Ah ok, what would you suugest, resistor?

  Joined November 12, 2019      2
Tuesday at 04:22 PM

The relay has a freewheel diode, therefore the relay has a polarity. If you riverse bias the diode it will conduct and dissipate heat depending on the psu current rating.
The diode is a very sensitive device that fails in regorous situations and creates dead shot.

Use the relay properly.

  Joined February 12, 2018      696
Monday at 02:11 PM

therefore the relay has a polarity

How can a relay have polarity??. It is a mechanical relay which operates on coil. So coils will not have polairty. just like an inductor or solenoid 

Are you telling that the frewheel diode is in-built into the relay? I dont think so 

 

  Joined August 27, 2018      25
Monday at 04:18 PM

Good day! This is Linda from KingCredie Technology Limited.

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  Joined March 23, 2020      4
Monday at 03:19 PM