# Delta Fan, does third wire (lock signal) need to be connected to run? **URL:** \ **Category:** Fans, Thermal Management\ **Tags:** electromechanical, delta-electronics, fans-blowers-thermal-management\ **Created:** [October 6, 2021, 1:42am UTC](https://forum.digikey.com/t/delta-fan-does-third-wire-lock-signal-need-to-be-connected-to-run/17054 "2021-10-06T01:42:40Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![marcus](https://avatars.discourse-cdn.com/v4/letter/m/85e7bf/32.png) [@marcus](https://forum.digikey.com/u/marcus)\ **Post date:** [October 6, 2021, 1:42am UTC](https://forum.digikey.com/t/delta-fan-does-third-wire-lock-signal-need-to-be-connected-to-run/17054/1 "2021-10-06T01:42:40Z")
Hi. I’m looking for some blower fans, most of the fans that would fit my propose are not in stock. The ones that are have more than 2 lead wires. I’m wounder; if the third wire is a tach or lock signal e.g. this [Delta Fan (BFB0524H-R00)](https://www.digikey.se/product-detail/en/delta-electronics/BFB0524H-R00/603-1990-ND/5799880), does it need to be connected for the fan to run?. The fans are for a part cooling solution on a Ender 3 v2 if that helps. Thanks, Marcus ---
**Author:** ![rick\_1976](https://sea2.discourse-cdn.com/digikey/user_avatar/forum.digikey.com/rick_1976/32/1571_2.png) [@rick\_1976](https://forum.digikey.com/u/rick_1976)\ **Post date:** [October 6, 2021, 3:30am UTC](https://forum.digikey.com/t/delta-fan-does-third-wire-lock-signal-need-to-be-connected-to-run/17054/2 "2021-10-06T03:30:01Z")
Greetings, Rotor lock or tachometer signal outputs do not need to be used in order for a fan to spin and move air. Most fans with speed control inputs are also configured to run at maximum speed if the control wire is unconnected, so those generally do not _require_ connection either. Further information on related topics can be found [here](https://forum.digikey.com/t/electrical-interfacing-monitoring-and-control/13298).