Could someone help clarify how the JQX-115F-Q power relay works? I appreciate this is a about a specific component so I've included a picture to show the markings. It's the markings that has got me confused, hopefully someone who understands this type of relay will be able to help.

The markings show 250VAC then above 9VDC and what I'd like to clarify is how should I interpret these markings?

I'm guessing it means one of the following but which?

  1. The relay works with either inputs of 250VAC and 9VDC or,
  2. Input of 250VAC will step down to 9VDC.

Side note: I'm trying to troubleshoot why my oven has stopped working. I've tested the input to be just under 240VAC (red and orange wires show in the picture) but I'm getting zero volts from the output (red wire). I think the relay is faulty so I want to bypass it but before I do I want to be clear that the expected output is same as the input and the replay is simply acting as a switch.

Here's a picture of the relay.

enter image description here

  • 1
    \$\begingroup\$ Why do you want to bypass the relay rather than replacing it? This will change the operation of the oven. Depending on your country, doing this yourself could expose you to liability if your modification fails. At the power levels involved here, you need to know what you're doing. \$\endgroup\$
    – user133493
    Jan 2, 2019 at 0:44
  • \$\begingroup\$ When the relay is energized, the two connections at the bottom should be shorted. If there is voltage across them when the relay is energized the relay is faulty. \$\endgroup\$ Jan 2, 2019 at 0:46
  • \$\begingroup\$ @replete standard safety/warning comment ;). Once I've proved the relay is faulty I'll be replacing the whole board that the relay is attached too. \$\endgroup\$ Jan 2, 2019 at 7:40

1 Answer 1


A relay is essentially an electrically-operated switch. Relays have two independent ratings: one for the coil or operating mechanism, and one for the switch contacts.

That relay is apparently intended to be operated by 9 V DC - the "9VDC" is in-line with a coil symbol.

The contacts are rated for up to 16 Amp at 250 VAC.

You would apply 9 VDC to the coil to cause the contacts to change position, and switch a 250VAC circuit.


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