Armstrong 20J99

Armstrong 20J99 delivers dependable performance as a 130-160F auto limit switch designed for HVAC systems and industrial controls. This compact sensor automatically disconnects equipment when the temperature hits the preset range, safeguarding motors, fans, and components from overheating.

With a rugged design built to withstand demanding environments, the Armstrong 20J99 provides reliable temperature sensing and repeatable switching across cycles. The 130–160°F switching range makes it ideal for furnaces, air handlers, boilers, dehydrators, and other critical systems where safety and uptime matter.

Engineered for easy integration into standard control circuits, this auto limit switch simplifies wiring and reduces installation time. It delivers consistent overheat protection without sacrificing efficiency, helping you extend equipment life and minimize unplanned outages.

• 130–160°F operating threshold for precise protection
• Easy wiring and quick installation into existing controls
• Rugged, compact housing designed for HVAC and industrial environments
• Reliable auto limit switching to prevent overheating
• Helps extend equipment life and improve system uptime