Product Overview
The Hatch RS12-105-277 is an electronic low voltage transformer designed for use with 12-volt halogen lamps. It converts 277 VAC input to 11.5 VAC output, providing a stable power supply for lighting applications. This transformer features short circuit protection, is rated for outdoor use, and is compatible with most commercially available dimmers.

Image: Hatch RS12-105-277 Electronic Low Voltage Transformer. This image shows the compact, rectangular transformer unit with its yellow label displaying model information and electrical specifications. Attached are black, white, and red wires for input and output connections.
Key Features
- Input Voltage: 277 VAC
- Output Voltage: 11.5 VAC
- Maximum Wattage: 105 Watts
- Electronic Short Circuit Protection: Enhances safety and product longevity.
- Moisture Resistant: Suitable for outdoor applications.
- Dimmable: Works with most commercially available dimmers.
- No Audible Noise: Operates silently.
- Soft Start Circuitry: Extends lamp life.
- Instant Hot Lamp Restrike: Quick re-illumination.
- Class P Type 1 Outdoor Approved: Certified for outdoor use.
Safety Information
Always disconnect power before installation or servicing. Installation should be performed by a qualified electrician in accordance with national and local electrical codes. Do not exceed the maximum wattage rating of 105 Watts. Ensure proper grounding to prevent electrical shock.
Setup and Installation
This transformer is designed for hardwire installation. Follow these steps for proper setup:
- Power Disconnection: Turn off the main power supply at the circuit breaker before beginning any wiring.
- Mounting: Securely mount the transformer in a suitable location, ensuring adequate ventilation and protection from physical damage.
- Input Wiring (277V): Connect the black wire from the transformer to the live 277V input line and the white wire to the neutral 277V input line. Ensure connections are secure and insulated.
- Output Wiring (11.5V): Connect the two red wires from the transformer to the 12V halogen lamp(s). Polarity typically does not matter for AC low voltage output, but follow lamp manufacturer's instructions if specified.
- Grounding: Connect the transformer's ground wire (if present, typically green or bare copper) to a reliable earth ground.
- Verification: Double-check all connections for correctness and security.
- Power Restoration: Restore power at the circuit breaker.
Note: The transformer is designed for 12-volt halogen lamps. Using other lamp types or exceeding the 105W maximum load may damage the unit or lamps.
Operating Instructions
Once properly installed and powered, the Hatch RS12-105-277 transformer operates automatically. It provides a stable 11.5V AC output for connected halogen lamps. If connected to a compatible dimmer, the light output can be adjusted via the dimmer control.
The electronic short circuit protection will automatically shut down the output in case of a short circuit, protecting both the transformer and the lamps. The unit will attempt to restart once the short circuit condition is removed.
Maintenance
The Hatch RS12-105-277 transformer is designed for maintenance-free operation. However, periodic checks are recommended:
- Cleaning: Keep the transformer free from dust and debris. Use a dry cloth for cleaning. Do not use liquid cleaners.
- Wiring Inspection: Periodically inspect wiring connections for any signs of wear, corrosion, or loosening. Ensure all connections remain secure.
- Environmental Check: Ensure the operating environment remains within specified temperature limits and that the unit is not exposed to excessive moisture beyond its moisture-resistant rating.
Note: Do not attempt to open or repair the transformer. There are no user-serviceable parts inside. Opening the unit will void any warranty.
Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Lamps do not light up. |
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| Lamps flicker or dim inconsistently. |
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| Transformer makes noise. |
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If troubleshooting steps do not resolve the issue, contact a qualified electrician or Hatch customer support.
Specifications
| Parameter | Value |
|---|---|
| Model Number | RS12-105-277 |
| Input Voltage | 277 VAC |
| Input Current | 0.38 Amps (at 277V) |
| Output Voltage | 11.5 VAC |
| Maximum Wattage | 105 Watts |
| Operating Frequency | 25 KHz |
| Power Factor | >0.95 |
| Sound Rating | A+ (No audible noise) |
| Maximum Case Temperature | 194°F (90°C) |
| Dimensions (L x W x H) | 3.03" x 2.00" x 0.81" (approx. 7.7 x 5.1 x 2.1 cm) |
| Item Weight | 8 ounces (approx. 0.5 lbs) |
| Certifications | UL Listed (E105439), Class P Type 1 Outdoor Approved |
| Features | Low harmonic distortion, Electronic short circuit protection, Moisture resistant, Soft start circuitry, Instant hot lamp restrike |
Warranty Information
Specific warranty details for Hatch products are typically provided at the point of purchase or on the manufacturer's official website. Please retain your proof of purchase for warranty claims. The warranty generally covers defects in materials and workmanship under normal use. Damage resulting from improper installation, misuse, or unauthorized modifications is typically not covered.
For the most current and detailed warranty policy, please refer to the official Hatch Lighting documentation or contact their customer support.
Customer Support
For technical assistance, product inquiries, or warranty support, please contact Hatch Lighting directly. You can typically find their contact information, including phone numbers and email addresses, on their official website.
Hatch Lighting Official Website: www.hatchlighting.com
Note: The phone number (813) 286-3008 was observed on the product label in the image, which may be a direct contact for Hatch Lighting.





