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2-Pack GK-C-1A-12D Relay - 40A 250VAC SPDT 5-Pin Industrial Power Relay - Compatible with HVAC Systems & Motor Controls - Fixes Compressor & Start Failures

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$21.79

$ 10 .99 $10.99

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About this item

  • 40A SPDT High-Current Switching: 12VDC coil with SPDT (Single Pole Double Throw) design handles 40A resistive / 20A inductive loads for HVAC compressors, industrial motors, and commercial equipment
  • OEM Direct Replacement: Exact match for GK-C-1A-12D relays and cross-compatible with Omron G8HE-1A4T-R and Panasonic JW2F-AC12V industrial relays
  • Error Code Resolution: Fixes HVAC "EC-5" (Compressor Relay Fault) and industrial motor "ERR-12" (Start Circuit Failure) errors
  • IP67 Sealed Durability: Waterproof housing protects against dust, moisture, and vibrations (-40°C to +125°C)
  • Certified Safety: UL 508, CSA C22.2, and RoHS compliant for industrial and commercial use.


This 2-pack GK-C-1A-12D SPDT relay provides robust high-current switching for HVAC systems and industrial machinery. Designed as a direct replacement for GK-C-1A-12D relays, it resolves critical failures in:

HVAC Systems: Fixes compressor relay faults triggering "EC-5" codes in Carrier 59TP6 units and Trane XR14 heat pumps.

Industrial Motors: Restores motor start functionality in Siemens SIRIUS M200D drives prone to "ERR-12" errors.

Commercial Equipment: Compatible with Allen-Bradley ControlLogix panels requiring 40A SPDT relays.

Key Features:

SPDT 5-Pin Configuration: Terminals 30 (COM), 87 (NO), 87a (NC), and dual coil pins (85/86) for bidirectional control.

Technical Specs:

Contact Material: Silver tin oxide (AgSnO)

Coil Resistance: 80Ω ±15%

Dimensions: 1.0" x 0.8" x 0.6" (25mm x 20mm x 15mm)

Certifications: UL 508, CSA C22.2, RoHS.

Cross-Compatibility:

Replaces Tyco VF4-40F11 and Bosch 0-332-209-150 relays in industrial applications.


Daniel Kirk
Reviewed in the United States on March 24, 2025
This SPST relay uses a 12V coil to switch up to 40A at 277VAC. The coil pins are on the bottom, while the switch contacts have two pins on the bottom and two tabs on the top. The schematic is on the bottom. Coil resistance measures 156 ohms. To test the minimum switching voltage, I used a 9V alkaline battery, which switched the relay easily, and a 6V carbon-zinc lantern battery, which did not switch it.