Name: Resideo AT140B1206/U Foot Mounted 120 Vac Transformer with 9 in Leadwires and Plastic End Caps
Brand: Resideo
SKU: HONE-AT140B1206/U
Price: 24.91 USD
Availability: InStock

Foot mounted 120 Vac Transformer with 9 in leadwires and plastic end caps

Resideo Foot mounted 120 Vac Transformer with 9 in leadwires and plastic end caps

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Frequency	60 Hz
Electrical Ratings	Primary voltage--120 Vac; Secondary voltage--27 V.O.C.
Mounting	Foot-mounted
Includes	Plastic end caps
Dimensions	1 11/16 in. high x 3 1/2 in. wide x 1 3/4 in. deep
UL	UL Component Recognized: B, D, E models. File# E14881
CSA	CSA Certified: A & B models.
Temperature Range (F)	-20 F to +105 F
Electrical Connections (Primary)(in.)	9 in. leadwires
Electrical Connections (Secondary)(in.)	9 in. leadwires
Electrical Ratings, Output	24 Vac at 40 VA

Installation Instructions for AT120, AT120A, AT140, AT140A, AT150A, AT175A Universal Trans PDF ↗
Maintenance/Product Reference Materials-Residential Combustion Application Selection and C PDF ↗

The AT140B1206 is a control transformer from Resideo (Honeywell Home), 140 VA, 120 V primary, foot mount.

Almost every heating and cooling control runs on 24 volts, and the transformer is what makes it. It takes line voltage in and delivers the low-voltage supply that the thermostat, the zone valves, the relays and the gas valve all share.

Size it by VA, not by voltage. VA is the load the transformer can carry, and every device on the control circuit adds to it — a zone valve pulls current while it drives, a relay coil holds current the whole time it is energized, and a Wi-Fi thermostat draws continuously. A transformer sized for the original equipment will not carry the same system after two zones and a smart stat have been added, and the symptom is intermittent: things work alone and fail together.

Mounting matters more than it looks. The transformer has to land where the enclosure has room and where the leads reach, and a foot-mount body will not sit in a knockout that was made for a plate mount.

Leadwires are 9 inches.

Brand: Resideo (Honeywell Home)
Manufacturer Part #: AT140B1206/U
Type: Control transformer
Rating: 140 VA
Primary: 120 V
Secondary: 24 Vac
Mounting: Foot
Leadwires: 9 in
UPC: 085267035170
Category: Transformers

Full Specifications

Application	40 VA general purpose transformers power 24 V AC circuits. Although typically used in heating/cooling control systems, they can be used in any application that doesn't exceed the load ratings
NEMA Rating	No
Primary Connection Size	9 in, 229 mm
Primary Connection Type	Primary Connection Type
Primary Input Voltage	120 V ac
Secondary Connection Size	9 in, 229 mm
Secondary Connection Type	Leadwires
Secondary Open Circuit Voltage	27 V.O.C.
VA Rating	40 VA
Frequency	60 Hz
Approvals and Standards	UL Component Recognized: B, D, E models. File# E14881, CSA Certified: A & B models, NEC Class 2
Includes	Plastic end caps
Ambient Operating Temperature (Max)	105 °F, 41 °C
Ambient Operating Temperature (Min)	-20 °F, -29 °C
Product Height	1.69 in, 43 mm
Product Width	3.5 in, 89 mm