Generac G077220, 077220A OEM Generator-Side Coil for Select 100A HSB Transfer Switches

Description

The Generac G077220 coil is a genuine OEM generator-side electromagnetic coil designed for select 100A Generac and Guardian home standby automatic transfer switches. Also identified as part number 077220A, this component replaces the earlier 77220A part number. Verify your transfer-switch model, serial number, and original coil position before ordering to help ensure compatibility.

Generac G077220 Coil: Key Features

The Generac G077220 coil is a replacement component for compatible automatic transfer-switch mechanisms. It is energized by the generator-side control circuit and is typically installed in the bottom position of the compatible mechanism.

Product features:

• Genuine Generac OEM replacement component
• Listed part number: G077220
• Alternate part number: 077220A
• Replaces part number: 77220A
• Generator-side transfer-switch coil
• Typically installed in the bottom position
• Designed for select 100A Generac and Guardian transfer switches
• Package quantity: 1 coil
• Condition: New

This is the generator-side coil, not the utility-side coil. The utility-side coil occupies a different position in the transfer-switch mechanism. Confirm the original component’s position before purchasing a replacement.

Generac G077220 Coil Specifications

Review the following product information before ordering the Generac G077220 coil.

Important: The 100A specification refers to the rating of the compatible transfer switch. It does not indicate the electrical current rating of the coil.

Compatibility and Part Number Verification

The Generac G077220 coil is intended for select 100A Generac and Guardian home standby automatic transfer switches. Compatibility should be confirmed against the specific transfer-switch model rather than assumed from the brand or amperage alone.

Before ordering, check the following:

• Transfer-switch model: Confirm the exact model number of your existing switch.
• Serial number: Use the serial number when checking compatibility with a parts supplier or qualified technician.
• Original part number: Compare the existing coil’s part number with G077220, 077220A, and the replacement reference 77220A.
• Coil position: Confirm that you need the generator-side coil, typically installed in the bottom position, rather than the utility-side coil.
• Application: Verify that your switch is among the compatible 100A Generac or Guardian models.

These checks can help prevent ordering the wrong component. If the original part number or switch configuration is unclear, confirm the correct replacement before installation.

Diagnosing a Generator-Side Transfer Switch Coil

A failed or shorted coil may require inspection of the surrounding control circuit and related components. When diagnosing a suspected problem with the Generac G077220 coil, inspect the related control circuit and the 084464 limit switches.

Do not assume that the coil is the only damaged component. Replace additional components only when inspection or testing confirms damage. A qualified technician can assess the circuit and determine which parts require replacement.

The generator-side coil is energized by the generator-side control circuit. It is distinct from the utility-side coil, which occupies a different position in the transfer-switch mechanism. Correct identification matters when inspecting the mechanism or sourcing replacement parts.

Safety and Installation Information

Warning: Transfer switches contain potentially lethal utility and generator voltage.

Installation and testing must be performed by a qualified technician after all utility, generator, and control-power sources have been isolated.

Do not attempt installation, electrical testing, or component replacement while the transfer switch or associated circuits remain energized. Follow the applicable manufacturer service instructions and appropriate electrical safety procedures.

Before beginning work, the technician should verify the transfer-switch model, original component number, coil position, and relevant circuit condition. The correct replacement part should be confirmed before the existing component is removed or another part is ordered.

Frequently Asked Questions

1. What part numbers are associated with the Generac G077220 coil?

The primary part number is G077220. The component is also identified as 077220A and replaces the earlier part number 77220A. Verify the original part number and switch model before ordering.

2. Is the Generac G077220 coil for the generator side or utility side?

The Generac G077220 is the generator-side electromagnetic coil. It is typically installed in the bottom position of a compatible transfer-switch mechanism. It is not the utility-side coil, which occupies a different position.

3. Will this coil fit every 100A Generac or Guardian transfer switch?

No. It is designed for select 100A Generac and Guardian home standby automatic transfer switches. Check the exact switch model, serial number, original part number, and coil position to verify compatibility before purchasing.

Order the Generac G077220 Coil

Choose the genuine Generac G077220 coil when you have confirmed that this generator-side replacement component matches your transfer switch. The part is also identified as 077220A and replaces 77220A.

Review your switch details before ordering, and consult a qualified technician if you need help identifying the correct component or diagnosing a transfer-switch problem.