MDI Mercury Displacement 35NO-277A Contactor

The MDI Mercury Displacement 35NO-277A Contactor is a mission-critical 1-pole 277V contactor designed for high-cycle industrial automation and HVACR applications where mechanical relays typically fail. Built for 35-amp loads, this unit utilizes mercury-to-metal contact technology, featuring a hermetically sealed stainless steel tube encapsulated in high-grade epoxy. This design prevents moisture ingress and voltage breakdown while ensuring arc-free switching, making it an ideal choice for mercury displacement relay replacements in dusty or oily environments. The 277V AC coil requires minimal pull-in power, significantly reducing heat rise and allowing for consistent HVAC contactor performance in high-ambient-temperature control cabinets. With a rated longevity spanning millions of cycles, this industrial heating contactor is optimized for resistive heating elements, lighting ballasts, and specialized motor controls. Field technicians prioritize this MDI 35NO-277A for its vertical mounting stability and maintenance-free operation in demanding commercial environments.

• Hermetic Protection: High-quality glass-to-metal seals and epoxy encapsulation shield internal components from dust, moisture, and corrosion.
• Quiet Operation: Mercury displacement technology eliminates the contact chatter and mechanical noise associated with standard electromechanical relays.
• Thermal Stability: Engineered to maintain reliable switching in high-temperature environments with minimal derating.
• Arc-Free Switching: Liquid mercury contacts prevent the pitting and oxidation common in traditional air-break contactors, extending the service life of the circuit.

What is the maximum output voltage for this contactor?
The MDI 35NO-277A is rated for an output range of 0 to 600 VAC, allowing it to handle various industrial power requirements effectively.

Can this unit be mounted in any orientation?
No. To ensure the liquid mercury correctly displaces and completes the circuit, this contactor must be installed in a vertical position as specified by the manufacturer.

What are the recommended termination sizes for the load?
This 35-amp series typically utilizes pressure connectors or #8 binding head screws suitable for 4-14 AWG wire, ensuring low contact resistance and secure connections.

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.