Resideo AT40A1139 Transformer
The Resideo AT40A1139 Transformer is a heavy-duty 40VA power supply designed for reliable 24V control circuits in residential and light commercial HVACR applications. Engineered with a 240V primary and a 26.5V secondary output, this NEMA Type D transformer ensures consistent voltage regulation for thermostats, zone valves, and gas valves. The channel frame mounting configuration allows for versatile installation directly onto a junction box or appliance manifold, making it a standard replacement for aging or failed HVAC control transformers. Utilizing 9-inch lead wires for high-voltage and low-voltage connections, it simplifies field wiring in tight enclosures. This Class 2 transformer is built to handle the inductive loads common in air conditioning and heating systems, preventing nuisance trips and ensuring long-term stability of the control string. When upgrading or repairing outdated systems, the Resideo AT40 series provides the necessary 24V step-down power required for modern digital controllers and electromechanical components.
Key Benefits
- Standard 40VA Rating: Provides sufficient power for most single-stage heating and cooling control systems.
- Robust NEMA Type D Construction: Designed for durability and efficient heat dissipation during continuous operation.
- Flexible Installation: Features channel frame mounting for secure attachment to various equipment surfaces.
- Pre-Stripped Lead Wires: Includes 9-inch color-coded leads to reduce installation time and improve connection integrity.
- Voltage Stability: Maintains a 26.5V secondary output to compensate for voltage drops in complex control loops.
Common Questions
What is the difference between a NEMA Type D and Type F transformer?
NEMA Type D transformers, like this Resideo AT40A1139, typically feature channel frame mounting and lead wire connections, whereas Type F models often utilize foot mounting or different terminal configurations. Always verify mounting footprints before selection.
Can this 40VA transformer replace a 30VA model?
Yes, you can substitute a higher VA rating as long as the primary voltage (240V) and secondary voltage (24V/26V) match. The 40VA rating indicates it can handle a higher load without overheating compared to a 30VA unit.
What causes these transformers to fail prematurely?
Most failures are due to external shorts in the 24V circuit, overloading the secondary beyond 40VA, or primary surges. Checking the amp draw of your contactors and relays is recommended during replacement.
Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.
Resideo AT40A1139 Transformer
The Resideo AT40A1139 Transformer is a heavy-duty 40VA power supply designed for reliable 24V control circuits in residential and light commercial HVACR applications. Engineered with a 240V primary and a 26.5V secondary output, this NEMA Type D transformer ensures consistent voltage regulation for thermostats, zone valves, and gas valves. The channel frame mounting configuration allows for versatile installation directly onto a junction box or appliance manifold, making it a standard replacement for aging or failed HVAC control transformers. Utilizing 9-inch lead wires for high-voltage and low-voltage connections, it simplifies field wiring in tight enclosures. This Class 2 transformer is built to handle the inductive loads common in air conditioning and heating systems, preventing nuisance trips and ensuring long-term stability of the control string. When upgrading or repairing outdated systems, the Resideo AT40 series provides the necessary 24V step-down power required for modern digital controllers and electromechanical components.
Key Benefits
- Standard 40VA Rating: Provides sufficient power for most single-stage heating and cooling control systems.
- Robust NEMA Type D Construction: Designed for durability and efficient heat dissipation during continuous operation.
- Flexible Installation: Features channel frame mounting for secure attachment to various equipment surfaces.
- Pre-Stripped Lead Wires: Includes 9-inch color-coded leads to reduce installation time and improve connection integrity.
- Voltage Stability: Maintains a 26.5V secondary output to compensate for voltage drops in complex control loops.
Common Questions
What is the difference between a NEMA Type D and Type F transformer?
NEMA Type D transformers, like this Resideo AT40A1139, typically feature channel frame mounting and lead wire connections, whereas Type F models often utilize foot mounting or different terminal configurations. Always verify mounting footprints before selection.
Can this 40VA transformer replace a 30VA model?
Yes, you can substitute a higher VA rating as long as the primary voltage (240V) and secondary voltage (24V/26V) match. The 40VA rating indicates it can handle a higher load without overheating compared to a 30VA unit.
What causes these transformers to fail prematurely?
Most failures are due to external shorts in the 24V circuit, overloading the secondary beyond 40VA, or primary surges. Checking the amp draw of your contactors and relays is recommended during replacement.
Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.
Product Information
Product Information
Shipping & Returns
Shipping & Returns
Description
The Resideo AT40A1139 Transformer is a heavy-duty 40VA power supply designed for reliable 24V control circuits in residential and light commercial HVACR applications. Engineered with a 240V primary and a 26.5V secondary output, this NEMA Type D transformer ensures consistent voltage regulation for thermostats, zone valves, and gas valves. The channel frame mounting configuration allows for versatile installation directly onto a junction box or appliance manifold, making it a standard replacement for aging or failed HVAC control transformers. Utilizing 9-inch lead wires for high-voltage and low-voltage connections, it simplifies field wiring in tight enclosures. This Class 2 transformer is built to handle the inductive loads common in air conditioning and heating systems, preventing nuisance trips and ensuring long-term stability of the control string. When upgrading or repairing outdated systems, the Resideo AT40 series provides the necessary 24V step-down power required for modern digital controllers and electromechanical components.
Key Benefits
- Standard 40VA Rating: Provides sufficient power for most single-stage heating and cooling control systems.
- Robust NEMA Type D Construction: Designed for durability and efficient heat dissipation during continuous operation.
- Flexible Installation: Features channel frame mounting for secure attachment to various equipment surfaces.
- Pre-Stripped Lead Wires: Includes 9-inch color-coded leads to reduce installation time and improve connection integrity.
- Voltage Stability: Maintains a 26.5V secondary output to compensate for voltage drops in complex control loops.
Common Questions
What is the difference between a NEMA Type D and Type F transformer?
NEMA Type D transformers, like this Resideo AT40A1139, typically feature channel frame mounting and lead wire connections, whereas Type F models often utilize foot mounting or different terminal configurations. Always verify mounting footprints before selection.
Can this 40VA transformer replace a 30VA model?
Yes, you can substitute a higher VA rating as long as the primary voltage (240V) and secondary voltage (24V/26V) match. The 40VA rating indicates it can handle a higher load without overheating compared to a 30VA unit.
What causes these transformers to fail prematurely?
Most failures are due to external shorts in the 24V circuit, overloading the secondary beyond 40VA, or primary surges. Checking the amp draw of your contactors and relays is recommended during replacement.
Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.
