I'm looking at this 10A, 277VAC relay and wondering if there is sufficient spacing between the low voltage (3.5V, 100mA) and the high voltage(277VAC, 10A). The foot print looks like this:

enter image description here

Are the 5V leads too close to the high voltage leads? Why aren't the high voltage leads on one side and the low voltage leads on the other side? Also, the use case is to be mounted on FR-4 and there will be a fuse before the high voltage goes to the relay.


2 Answers 2


The biggest clue that the part is OK is the UL Recognized component mark (the backwards-looking "RU" symbol with C and US) on the part.

You will have to make sure that your PCB traces keep the necessary creepages and clearances, but the part itself (and the pinouts) are perfectly acceptable per UL and therefore not a cause for concern.

The pinout logic is most likely a function of the physical construction of the part given the form factor, or it could be to make it pin-compatible with some other vendor.

  • \$\begingroup\$ You already know this, but for OP's benefit I'll add that the UL mark is a valid indicator if you are buying these parts directly from TE or a trustworthy supply chain. If you see that mark on parts randomly bought from EBay or something, I wouldn't trust my life to it. \$\endgroup\$
    – The Photon
    Commented Aug 24, 2012 at 15:42
  • 1
    \$\begingroup\$ You can always go to the UL website and look up the file number listed on the part or datasheet if you have a doubt. \$\endgroup\$ Commented Aug 25, 2012 at 11:49

Almost certainly not. The people selling that would have thought of that, giving that you are using it within its ratings.

Since you can connect to the high voltage from the right and the low voltage from the left, there isn't a need for the traces to overlap. It does seem odd, though.


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