Honeywell L4079A1050 Controller

The Honeywell L4079A1050 Pressuretrol Limit Controller is a high-pressure safety switch designed for critical monitoring in steam, air, and non-combustible gas systems. Engineered with a 10-150 PSI operating pressure range, this unit provides essential overpressure protection for commercial boilers and industrial fluid systems. It features a rugged stainless steel diaphragm and dual SPST switches that break simultaneously upon pressure rise, ensuring both sides of a power supply are interrupted for maximum safety. As a manual reset pressure switch, it requires technician intervention following a trip, preventing the system from automatically cycling under fault conditions. The L4079A1050 is a direct functional replacement for the L4079A1050/U, utilizing 1/4 inch NPT internal threads for straightforward pressure control installation on a siphon loop or via surface mounting through the back of the case. Rated for 120Vac/240Vac, this high limit controller maintains set-point integrity even in environments with moderate vibration.

• Dual Circuit Interruption: Two ganged SPST snap-acting switches break simultaneously to provide comprehensive circuit isolation during high-pressure events.
• Corrosion Resistance: The stainless steel diaphragm allows for reliable operation with steam, compressed air, and fluids non-corrosive to stainless steel.
• Fail-Safe Manual Reset: The trip-free reset mechanism ensures the safety limit cannot be bypassed by jamming the reset lever, necessitating a physical inspection before restarting.
• Versatile Mounting: Supports both 1/4 in. NPT pipe fitting and surface mounting for flexible integration into existing boiler manifold configurations.
• Technician-Friendly Design: Features a transparent cover for immediate visual inspection of the Micro Switch contacts and status.

Can the Honeywell L4079A1050 be used for oil applications?
No. While this model is compatible with steam and air, oil burner applications require the L4079W model, which includes specific seals for oil compatibility.

Does this controller require leveling during installation?
This Honeywell Pressuretrol does not require leveling and remains unaffected by moderate vibration, though it is standard practice to mount it vertically when using a steam trap/siphon.

How do the SPST switches operate on this model?
The switches are designed to "break on rise." When system pressure reaches the set point, both SPST switches open simultaneously to cut power to the burner or control circuit.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.