I am planning on using the Relay Shield and a Photon to control the motor of a ventilation fan. However, I am now questioning whether I can control the motor from the relays, or use the relays to control contactors which in turn control the motor.
The motor is single phase, 120V AC, 60Hz, 1/20Hp with operating current of 1.7A.
Digging deeper, it is a “shaded pole” design. I was not able to find any information about the inrush current for start-up.
The Panasonic JS relays on the Particle Relay Shield are rated for 10A at 125V AC. On first glance, that looks good. However, the Panasonic General Application Guidelines caution that motor inrush current could be 5x to 10x the steady state current. That means an estimated inrush current of 8.5A to 17A. That is a very high current and probably exceeds the relay rating. However, the caution indicates inrush could last up to 0.5 seconds.
Does anyone have real-world experience with these relays for controlling inductive loads?
I searched for inrush current information for my motor, but could not find anything.
Searching in general for inrush current for shaded pole motors also turned up no information. Is there any experience if the Panasonic estimates are realistic for a motor such as this?
Also, the general application guidelines seem to indicate a CR circuit is the best choice to protect the relay contacts for an inductive load(motor). Would this still be recommended to protect the contactor contacts, in case using contactors to control the motor is recommended. Again, would this same protection be used to protect the relay when driving the contactor, as I would assume a contactor is also an inductive load?