Westinghouse 621709R Air Handler Transformer 40 Va

Product Description

The WESTINGHOUSE 621709R is a 40 VA control transformer designed for residential air handler systems. It steps down line voltage from 208 or 240 volts to 24 volts, supplying the low-voltage control circuit that powers the thermostat, contactor coils, and other control components. This transformer is an OEM-specified replacement part intended for installation by licensed HVAC technicians. Its 40 VA rating provides sufficient capacity for standard low-voltage control loads found in forced-air air handler applications.

This transformer is rated for use in air handler applications where 208-volt or 240-volt primary power must be converted to a 24-volt secondary control circuit. It is specified as a direct replacement for units in the MB7BM model family, including the MB7BM-0800K-A, MB7BM-1200K-A, and MB7BM-1200K-B air handlers. It is suited to residential forced-air systems where a low-voltage control circuit is required to interface with a standard thermostat and associated control components.

Key Features

• 40 VA transformer rating supports standard low-voltage HVAC control loads
• 208 or 240 volt primary to 24 volt secondary step-down configuration
• OEM-specified replacement for MB7BM-series air handlers
• Listed to UL and CSA applicable standards

Compatibility

Specified replacement for WESTINGHOUSE air handlers MB7BM-0800K-A, MB7BM-1200K-A, and MB7BM-1200K-B.

Installation Notes

Installation should be performed by a qualified HVAC technician. Disconnect and lock out all power to the air handler at the disconnect switch or breaker before removing the existing transformer or making any wiring connections. Verify that primary voltage at the unit matches the transformer primary rating of 208 or 240 volts before energizing. Work should comply with applicable NEC requirements and local electrical codes.

Technical Specifications

• VA Rating: 40 VA
• Primary Voltage: 208 or 240 volts
• Secondary Voltage: 24 volts
• Used On Item: Air Handler
• Compatible Part Numbers: MB7BM-0800K-A, MB7BM-1200K-A, MB7BM-1200K-B
• Certifications: UL, CSA

Standard Information

• Brand: WESTINGHOUSE
• Manufacturer Part Number: 621709R