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I've got a single phase inductive motor rated at 1.1 kW, 220 - 240 V, and 7.1 A.

Can I safely connect this motor to a WiFi switch rated to handle 100 - 240 V and 10 A?

Clearly the switch can handle the rated current, but what about the ~6x inrush current when the motor turns on? Does the rating for the switch allow for very short overcurrents?

Followup question: if the answer is no, I can't safely use this switch, must I find a switch/relay rated to handle ~40 A?

Thank you very much for the help!

EDIT: The spec sheet can be found at http://sonoff.tech/wp-content/uploads/2021/03/%E4%BA%A7%E5%93%81%E5%8F%82%E6%95%B0%E8%A1%A8-BASICR2-RFR2-20201218-1.pdf, the full manual at http://sonoff.tech/wp-content/uploads/2021/03/%E8%AF%B4%E6%98%8E%E4%B9%A6-BASICR2-RFR2-V1.2-20210305-1.pdf, and the general webpage for the device at https://sonoff.tech/product/diy-smart-switches/basicr2/

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  • \$\begingroup\$ Please link the data sheet for the Wi-Fi switch that explains in detail about the current ratings for its switch contact. \$\endgroup\$
    – Andy aka
    May 3, 2023 at 14:02
  • \$\begingroup\$ Forget it, that Sonoff is dangerous overseas garbage, it's not going to hold up to a motor load. Things which touch AC power need to be approved by your designated authorities (e.g. UL/CSA/ETL/BSI/TUV). \$\endgroup\$ May 4, 2023 at 7:02

1 Answer 1

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It's standard practice to use a motor contactor 'K1', with a thermal overload relay 'F2', to control such a motor.

Here's the schematic.

enter image description here

'F1' is a miniature circuit breaker for short circuit protection.

The contactor coil is energised by the 'NO' contact of the WiFi switch 'K11'.

In the event of an overload, the 'NC' contact of 'F2' trips the motor.

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