How to install 12V low voltage lighting?

Low voltage (12 V AC or DC) lighting is used for landscape lighting, kitchen cabinets, and pools. Here are the rules according to the Quebec Construction Code:

General rules:

• The 120 V / 12 V transformer must be CSA/UL certified and installed in an accessible, dry location
• Transformer max power: calculated based on total luminaire load (e.g., 10 luminaires at 12 W = 120 W, use a 150 VA transformer)
• Distance between transformer and luminaires: max 15 meters with #14 AWG wire (voltage drop)
• Low voltage conductors can be buried at 150 mm (6 in) depth (vs 450 mm for 120 V)

Connections:

• Low voltage connections must be waterproof (for outdoors) — use gel or silicone connectors
• 12 V conductors do not need to be in conduit if buried or mechanically protected
• A GFCI breaker is recommended on the 120 V side feeding the outdoor transformer

Color code: Low voltage wires are often red/black (12 V) or white/black. No standardized color code, but connections must be clearly marked "12 V".