Which wire gauge sizes fit inside the built-in horizontal and vertical panel chases without de-rating?

Standard 14 AWG and 12 AWG non-metallic sheathed cables fit inside InSoFast horizontal and vertical panel chases without ampacity de-rating when run as single branch circuits on 15-ampere and 20-ampere breakers.

Running wiring through continuous insulation panels eliminates the labor of cutting custom channels on job sites across the United States and Canada. Under National Electrical Code (NEC / NFPA 70) standards, residential branch wiring placed inside thermal insulation retains standard ampacity ratings unless cables are bundled together or exposed to ambient room temperatures exceeding 86°F (30°C).

If you only do one thing: Run standard 14/2 or 12/2 NM-B (non-metallic sheathed) cable flat within individual pre-formed channels without stacking multiple cables in a single chase to avoid triggering conductor derating requirements.

• 14 AWG copper branch circuits: Accommodates standard 14/2 and 14/3 NM-B cables on 15-amp circuits, allowing general lighting, outlet, and smoke detector circuits to pull through horizontal or vertical channels without modifying the EPS (expanded polystyrene) foam.
• 12 AWG copper branch circuits: Houses 12/2 and 12/3 NM-B cables rated for 20-amp kitchen, bathroom, and dedicated utility circuits while maintaining full 20A overcurrent protection under standard NEC Table 310.16 calculations.
• Single-run cable placement: Keeps each factory raceway limited to a single NM-B flat cable run, preventing heat buildup that would otherwise require ampacity reduction under NEC Section 310.15(C)(1) conductor bundling rules.
• Built-in raceway layout: Utilizes horizontal raceways spaced at 16 inches on center and vertical chases aligned with studs, enabling continuous wire pulls without notching framing or drilling into concrete masonry walls.
• Electrical box cutout integration: Supports standard outlet boxes placed directly into foam cutouts made with a utility knife or hot knife, maintaining depth alignment with drywall attached to the built-in studs.

• Watch out for: Bundling more than two NM-B cables through the same raceway crossing, which forces ampacity adjustments down to 80% or 70% of table values under national electrical bundling codes. Consult a licensed electrician for complex multi-circuit raceway layouts.
• Watch out for: Using armored metal-clad cable (Type AC/MC) or rigid conduit without enlarging the factory chases, as metallic sheathing requires custom carving to sit flush behind wall finishes.
• Watch out for: Skipping low-expansion spray foam around electrical box cutouts, which creates thermal voids and air leaks behind drywall.

Map circuit paths across your panel layout to verify 14 AWG and 12 AWG run counts before mounting panels, or contact InSoFast technical support for project-specific installation assistance.