Looking for Self powered relay - Page 1
Forum section: electronics / projects

author: Algoma
author_rank: Frequent Contributor
timestamp: May 03, 2022, 03:38:42 pm
content: Has anyone seen a simple self powered Mains AC relay that can be activated by a simple microswitch across an input. Someting self contained without having to impliment a seperate power supply / Controller.I have a LittleGiant condensate pump motor (1/30HP @ 1.5A) powered through a tiny crouzet 83133169 microswitch (5A/250V) as the water level rises. Poor switch blows out its contacts after less than a year of service due to moisture, surge current and internal arcing. Individual cost of each of these Microswitches are quite high compared to similar switches due to their high demand, and designed to fail product design. I've bought 8 of then over the years.. rest of the pump is still flawless condition.https://www.digikey.com/en/products/detail/crouzet/83133169/3874503All else fails, its easy enough to impliment a 12V Low Voltage Power Supply through the microswitch to activate a Solid State Relay. Just hoping for something a bit more self-Contained without the need for a seprate Low voltage supply taking up more space in a moisture prone area. Less seperate wires, the better.5 Contacts (120V AC Live and Neutral inputs, 120V Live Output and Return from Pump Motor, Current limited N/O Dry Contact Pins to activate Output Relay).

author: themadhippy
author_rank: Super Contributor
timestamp: May 03, 2022, 03:44:16 pm
content: Whats up with a relay with a 120v AC coil?

author: bdunham7
author_rank: Super Contributor
timestamp: May 03, 2022, 03:52:59 pm
content: Quote from: themadhippy on May 03, 2022, 03:44:16 pm

author: Algoma
author_rank: Frequent Contributor
timestamp: May 03, 2022, 05:42:56 pm
content: This company seems to make plenty of good options for sealed pre-wired AC relays that will work safely for the application.https://www.functionaldevices.com/product-category/relays/

author: eblc1388
author_rank: Frequent Contributor
timestamp: May 04, 2022, 06:38:08 am
content: Quote from: Algoma on May 03, 2022, 03:38:42 pmYes. They are called AC to AC SSRs but very few manufacturers make them. In your case, a SSR which takes 120V AC and close a contact for AC load. You have to search a bit on the net but if you got it, the modification to your existing connection is simple.

author: Algoma
author_rank: Frequent Contributor
timestamp: May 04, 2022, 07:06:32 pm
content: Thank you each for pointing me in the right direction, I've settled for using a Sensata-Crydom ED24B5Nice and compact size AC Solid State Relay (SSR) that should easily fit within the housing, connected using simple spade connections.Output Type: AC, Zero CrossVoltage - Input 90 ~ 140VAC (<5mA drawn by the input)Voltage - Load 24 V ~ 280 VLoad Current 5 A (Plenty for this application, with a decent maxiumum surge rating)Termination Style Plug In, Quick Connect - 0.187" (4.7mm)https://www.digikey.com/en/products/detail/sensata-crydom/ED24B5/2665167https://www.sensata.com/sites/default/files/a/sensata-ed-series-ac-output-plug-in-ssr-datasheet.pdfI'll upload pics and final wiring once I get the part, for future reference if anyone else is looking for a solution to this issue.