Feature

●Primary Voltage: 120/208/240 V AC. Secondary Voltage: 24 V AC
●Specification: 40VA volt amp rating
●Wide compatibility: this transformer is designed for Doorbell， thermostat， use in industrial, heating and air conditioning controls, including air conditioning circuits, relays, and gas valves or other applications that do not exceed the listed ratings
●Compatible With: This transformer compatible for Honeywell, Nest, Ecobee, and Sensi smart thermostats; Also compatible with Video Doorbell, Video Doorbell 2, Video Doorbell Pro, Nest Skybell Doorbell
●Hight Quality EI type Isolation Class 2 Control Transformers


Description

24VAC control transformer Replacement for: Mars 50203 Armstrong TWF424-40 Gemline GT446 Robertshaw 620-206, 620-406, 620-482 Supco SXT105 White-Rodgers GT4031F, 90-T40F3 Grainger 6WU91 Honeywell AT140A1018, AT40A1121, AT40A1139, AT40B1214 Source 1 S1-T2404F Packard PF42440 Note: All the related brands and control transformers brand names mentioned above is only for demonstrating compatibility.

FOR THERMOSTATS
Shut off the circuit breaker power supply
Install any wire from the 24 volt adapter to the "C" end and another wire
to the "RC" end. If your system has a cooling system, you may need to
use the included diode and connect the “RH” to the RC’ terminal.
Plug the power adapter into the socket
Open the circuit breaker power supply
Install the panel on the thermostat

FOR DOORBELLS
Keep adapter unplugged
Install wires from 24 volt adapter into the terminals for your doorbell unit
(any wire can be connected to any terminal)
Plug adapter into outlet
Put doorbell face plate on housing unit
Power up and verify your doorbell is receiving necessary power using the accompanying application

Wild Using
This is a device that you can keep your machine continuously charging your doorbells or thermostats. Many old homes or apartments do not have a "C" wire to their current thermostat, and newer devices require a C-wire to power the device.This simple product allows you to make the problems