Mercury Relays

Power-supply manufacturer Carlo Gavazzi recently released a series of switching devices the company deems "economically friendly," the RMD Hybrid Relays. The product provides mercury-free switching, designed for controlling heating elements inside of food ovens, warmers, fryers, rotisseries and other food equipment. It's capable of switching up to 20 cycles per minute, with a 4 million electrical cycle life expectancy.

The RMD Series combines solid-state technology and electromechanical relays to provide a hybrid relay. This means that there is virtually no contact arcing, which  results in prolonged relay life and much less emission inside of the panel. Another benefit of hybrid technology is a full amperage rating at elevated operational temperatures. While most conventional switching devices are rated at 25-40 degrees Celsius, the RMD Hybrid Relays are fully rated up to 60 degrees Celsius. The RMD3H switches heaters on three legs while the RMD2H is a lower-cost alternative, as it switches two poles and the third pole is directly connected between L2 and T2. Additional technical features include:

• Two- (for single and three phase circuits) and three-pole arrangements
• Rated for 4 million electrical cycles
• Rated for up to 20 cycles per minute
• Two output voltage ratings: 240VAC (VL-L) and 277VAC (VL-N – 480VAC with Neutral)
• Three common control voltages: 24VAC, 120VAC, 240VAC
• Two amperage ratings: 30A up to 70 degrees Celsius, 40A up to 60 degrees Celsius
• Similar mounting to Mercury Displacement Contactors
• Mercury-free, RoHS compliant, cRUus recognized

The Carlo Gavazzi RMD series provides a mercury-free switching solution which is ideal for controlling heating elements inside of food ovens, warmers, fryers, rotisseries and other food equipment.

They are not many items on the market which are capable of switching up to 20 cycles per minute, with a 4 million electrical cycle life expectancy!

The Carlo Gavazzi RMD Series combines the benefits of solid state and electromechanical technology and provides a hybrid relay.

This means that there is virtually no contact arcing, which results in prolonged relay life and much less emissions inside of the panel. Another benefit of hybrid technology is a full amperage rating at elevated operational temperatures.

While most conventional switching devices are rated at 25°C or 40°C, the Carlo Gavazzi RMD relays are fully rated up to 60°C.

The RMD3H switches heaters on three legs while the RMD2H is a lower cost alternative, as it switches two poles and the third pole is directly connected between L2 and T2. 

Marshall Wolf Automation is your authorized industrial automation distributor for the full range of Carlo Gavazzi sensors and Carlo Gavazzi relays.

Search all of our Carlo Gavazzi products now!

• One pole hybrid relay with one switching pole
• 17.5mm housing
• Capable of switching up to 20 amp heaters at 6 cycles per minute
• Temperature up to 77°F

Carlo Gavazzi RMD2H

• 3-phase hybrid relay with two switched poles and one live pole
• Can switch loads up to 40 amp heaters at 20 cycles per minute
• Temperature up to 140°F
• This is an economical version of the RMD3H

• 3-phase hybrid relay with all three poles being switched
• Eliminates any phase imbalance & provides safer switching
• Can switch loads up to 40 amps at 20 cycles per minute
• Temperature up to 140°F

Another benefit of hybrid technology is a full amperage rating at elevated operational temperatures. While most conventional switching devices are rated at 25°C or 40°C, the RMD Hybrid Relays are fully rated up to 60°C. The RMD3H switches heaters on three legs while the RMD2H is a lower cost alternative, as it switches two poles and the third pole is directly connected between L2 and T2.

Some of the technical features of the Carlo Gavazzi RMD series include:

• Extremely long life
• Low, predictable contact resistance
• Compact in size
• Handles a variety of loads
• Low coil power requirements
• Rapid on-off cycling capability
• Only one moving part (plunger)
• Reduced downtime
• Simple to install

Are you looking for one distributor for all of your industrial automation needs?
Marshall Wolf Automation is that distributor!

We carry a full line of industrial automation products including:

• AC drives - variable frequency drives
• Industrial light towers - stack lights, beacons, tower lights
• Sensors - photoelectric, inductive and capacitive proximity sensors, ultrasonics & more!
• Relays - solid state, mercury, ice cube, terminal block style
• Motors - AC and DC motors, gearmotors, all types
• Industrial DC power supplies - panel mount and DIN rail mount

The Delta DOP-B10 series HMI's are available in 10.1” wide screen vivid 65536 Color TFT display. These Industrial Operator Interfaces provide 3 COM ports (1 x RS-232 and 2 x RS232/485/422) to allow the user to communicate with different controllers simultaneously.

For global environment protection, DOP-B series all models are equipped with LED backlights free from eco-problems caused by mercury contamination, which save energy, reduce carbon dioxide (CO2) emissions and offer more eco-friendly automation products. Major applications include, but are not limited to, HVAC, Printing Machine, Exposure Machine and Product Line Monitoring Equipment.

Marshall Wolf Automation is an Industrial Automation Distributor. We can provide your Interface needs as well as a multitude of other items. Please see a sampling of our offerings at www.wolfautomation.com.

Mercury displacement relays from MDI are all designed and built to meet the requirements of your toughest applications!

Mercury relays have won their high place in the electrical field by doing the tough and tricky jobs that ordinary equipment could, at best, do in an uncertain manner. 

MDI mercury relays have proven their ability to stand up under the most adverse conditions of temperature, dust and moisture, in all types of applications.

All the care required for the manufacture of high-grade instruments is used in the manufacture of the switches. All switch parts are specially cleaned, and contamination is avoided by use of tweezers, gloves, etc., when making assemblies.

Other features of MDI mercury relays:

• Contactors are hermetically sealed with high quality glass to metal seals.
• The stainless steel tube is totally encapsulated in high grade UL approved epoxy to prevent moisture damage and voltage breakdown through the protective coating.
• The coils are wound on compact nylon bobbins and molded onto the metal tube to provide minimum power loss.
• Inert gases internally prevent excessive arcing between the mercury and the electrodes which enables the unit to function for millions of cycles with very low contact resistance, and minimum deterioration of the internal parts.
• Available in all standard coil voltages, in single, two and three pole arrangements. Other coil voltages available upon request.
• In multiple pole units each tube is actuated by its own coil. This eliminates pull-in variation between contact tubes, assuring consistent switching.

• 10 amps @ 3500VAC
• 15 amps @ 2500VAC
• AC inductive power factor .7 or greater
• Available in coil voltages from 24VDC to 220VAC

• the larger product is used in manufacturing; or
• the switch or relay is integrated in and not physically separate from other components of the larger product."

• 1, 2 or 3 pole mercury relays
• AC or DC voltages
• 30 to 100 amp
• Unbeatable pricing!
• Easy online ordering
• Simple cross referencing from other mercury relay manufacturers