Can someone explain this relay pin drawing to me? It is a Releco C5-A30. Why are the contacts labeled twice, bold and not? Can someone explain how they'd wire this for just a simple N/O switch?

screenshot of photo of relay and the relay connection diagram from the datasheet

  • \$\begingroup\$ What do you intend supply to coil AC or DC? and contacts? \$\endgroup\$ – Sunnyskyguy EE75 Sep 8 '17 at 21:23

It's not a simple NO switch, it's a three pole dual throw relay switch.

As to the double numbering, the not bold numbers are European standard terminal markings where first digit is the pole, second is a contact codes 1 = common, 2 = NC and 4 = NO. The BOLD numbers are everybody else.

enter image description here

If you look at the socket for it, you will see the same markings.

enter image description here

If you WANT to wire it as a simple single pole NO relay, hook up your coil voltage across A & B, and use either pin pairs 4 & 7, 5 & 8 or 6 & 9 as your switch.

  • \$\begingroup\$ The bold numbers is the pin labeling in the socket to the relay, see "Dimensions [mm]" in the datasheet. \$\endgroup\$ – MatsK Sep 8 '17 at 20:58
  • \$\begingroup\$ That's "three pole, double throw". \$\endgroup\$ – WhatRoughBeast Sep 8 '17 at 23:09
  • \$\begingroup\$ @WhatRoughBeast each pole is a single connection, 3 poles means there are 3 switched being controlled together. Dual throw means a switch with a normally open and normally closed contact. \$\endgroup\$ – ratchet freak Sep 9 '17 at 0:32
  • \$\begingroup\$ @ratchetfreak - conceivably usage has changed, but I'm pretty sure the it's "double", not "dual". The adjective for one is single, the adjective for 2 is double, and for 3 it's triple. for instance, if you google SPDT, you get en.wikipedia.org/wiki/SPDT and there are almost no links to "single pole dual throw". \$\endgroup\$ – WhatRoughBeast Sep 9 '17 at 13:27
  • \$\begingroup\$ @WhatRoughBeast interesting, it was always dual in my neck of the woods, but the meaning is the same I guess. \$\endgroup\$ – Trevor_G Sep 9 '17 at 13:47

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.