WHAT ARE MERCURY DISPLACEMENT RELAY CONTACTORS?
Mercury displacement relay contactors are devices for repeatedly establishing and interrupting electric power circuits. They make and break power circuits to such loads as electric transformers, capacitors and heaters.
WHERE ARE THEY USED?
Typical applications of mercury displacement contactors are:
● Dusty, oily locations
● High cycle rate applications
● Low voltage switching
● Plastic injection molding applications such as; blow molding, injection and extrusion
● Unit heaters
HOW DO MERCURY DISPLACEMENT CONTACTORS WORK?
A mercury contactor uses a pool of mercury, inside a glass sealed tube, to electrically connect two contacts. Basically, a mercury wetted contact relay consists of one or more glass switch capsules surrounded by a coil. When the coil is powered causing a magnetic field, the plunger assembly inside the glass capsule is pulled down into the mercury pool, which is in turn displaced and moved up to make the contact with the electrodes. When the two contacts wetted with mercury are joined, the area of contact between the surfaces is somewhat large because a fillet of mercury surrounds the mated surfaces. When the two surfaces are separated, the mercury stretches into a thin filament and then breaks at two points that isolate a thin rod of mercury in the middle. The thin rod then snaps into a ball and drops to the bottom of the switch. Thus, in effect, the mercury wetted contact relay provides a new contact surface for each closure. A mercury displacement contactor ideally runs 3-8 million overall cycles. When used 24 hours a day in a heater application, there may be 3 million on/off cycles in a single year.
HOW ARE THEY MANUFACTURED?
Mercury displacement relay contactors are all designed and built to meet the most exacting demands of industry. They have proved their ability to stand up under the most adverse conditions of temperature, dust and moisture, in all types of applications. The 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. This allows for low coil power to actuate the contactor. This also enables the units to handle high loads with minimum derating due to higher ambient temperatures. 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.
Mercury Displacement Contactors are all designed and built to meet the most exacting demands of industry. Their service life is equal to that of the solid state contactor, even under adverse conditions of temperature, dust and moisture. Each pole is hermetically sealed with high quality glass-to-metal seals to prevent moisture damage and voltage breakdown through the protective coating. Mercury Contactors are available in single or multiple pole units and in several coil voltages. Purchase the best contactors.
Advantages over mechanical contactors:
● Superior performance and reliability for longer life and durability.
● More compact size for easy installation.
● Lower, predictable contact resistance.
● Handles a variety of loads for increased design flexibility.
● Lower coil power requirements.
● Minimal derating due to higher ambient temperatures.
● Quieter action.
HOW TO SELECT AN APPROPRIATE MERCURY DISPLACEMENT CONTACTOR
There are many different factors to consider when deciding which mercury contactor is right for your application:
● Number and type of contacts – (e.g. Normally Open, Normally Closed)
Normally Open contacts connect the circuit when the relay is activated; the circuit is disconnected when the relay is inactive. This is ideal for applications that require switching to a
high current power source from a remote device.
Normally Closed contacts disconnect the circuit when the relay is activated; the circuit is connected when the relay is inactive. This is ideal for applications that require the circuit to
remain closed until the relay is activated.
● Rating of contacts
● Voltage rating of contacts
● Coil voltage
● Longevity: millions of cycles
● Mounting (sockets, rail mount, panel mount)
● Switching times
● Regulatory approvals
WE OFFER THE FOLLOWING SPECIFICATIONS
35/60-Amp Specifications (Normally Open units):
● Operate Time: 50 milliseconds
● Release Time: 80 miliseconds
● Contact Resistance: 35-Amp = .003 ohm (after cycling under load) 60-Amp = .002 ohm (after cycling under load)
● Dielectric Withstand: 2500 VAC RMS
● Longevity: millions of cycles
● Temperature Range: -35°C to 85°C
● Coil Terminals: #6 binding head screws
● Load Terminals: pressure connectors for A.W.G. #4-#14 on 35-Amp units and A.W.G. #2-#8 on 60-Amp units
100-Amp Specifications (Normally Open units):
● Operate Time: 50 milliseconds
● Release Time: 80 miliseconds
● Contact Resistance: .001 ohm (after cycling under load)
● Dielectric Withstand: 2500 VAC RMS
● Longevity: millions of cycles
● Temperature Range: -35°C to 85°C
● Coil Terminals: #6 binding head screws
● Load Terminals: pressure connectors (standard accepts A.W.G. #2-#12)
| 1 POLE - NORMALLY OPEN | ||||
| LOAD RATE |
VOLTAGE | VOLT AMPERES A/P |
POWER (watts) |
PART NO. |
| 35-AMP | 120VAC | 6.4 | 3.5 | 35NO-120A |
| 24VDC | 3.3 | 3.3 | 35NO-24D | |
| 240VAC | 6.2 | 3.8 | 35NO-220A | |
| 60-AMP | 120VAC | 5.8 | 2.9 | 60NO-120A |
| 24VDC | 3.3 | 3.3 | 60NO-24D | |
| 240VAC | 5.9 | 3.5 | 60NO-220A | |
| 100-AMP | 120VAC | 16.4 | 7.1 | 100NO-120A |
| 24VDC | 8.9 | 8.9 | 100NO-24D | |
| 240VAC | 32.2 | 7.5 | 100NO-220A | |
| 2 POLE - NORMALLY OPEN | ||||
| LOAD RATE |
VOLTAGE | VOLT AMPERES A/P |
POWER (watts) |
PART NO. |
| 35-AMP | 120VAC | 12.8 | 7.0 | 235NO-120A |
| 24VDC | 6.6 | 6.6 | 235NO-24D | |
| 240VAC | 12.4 | 7.6 | 235NO-220A | |
| 60-AMP | 120VAC | 11.6 | 5.8 | 260NO-120A |
| 24VDC | 6.6 | 6.6 | 260NO-24D | |
| 240VAC | 11.8 | 7.0 | 260NO-220A | |
| 100-AMP | 120VAC | 32.8 | 14.0 | 2100NO-120A |
| 24VDC | 17.8 | 17.8 | 2100NO-24D | |
| 240VAC | 32.2 | 15.0 | 2100NO-220A | |
| 3 POLE - NORMALLY OPEN | ||||
| LOAD RATE |
VOLTAGE | VOLT AMPERES A/P |
POWER (watts) |
PART NO. |
| 35-AMP | 120VAC | 19.2 | 10.5 | 335NO-120A |
| 24VDC | 9.9 | 9.9 | 335NO-24D | |
| 240VAC | 18.6 | 11.4 | 335NO-220A | |
| 60-AMP | 120VAC | 17.4 | 8.7 | 360NO-120A |
| 24VDC | 9.9 | 9.9 | 360NO-24D | |
| 240VAC | 17.7 | 10.5 | 360NO-220A | |
| 100-AMP | 120VAC | 49.2 | 21.3 |
3100NO-120A |
| 24VDC | 26.7 | 26.7 | 3100NO-24D | |
| 240VAC | 48.3 | 22.5 | 3100NO-220A | |
| 4 POLE - NORMALLY OPEN | ||||
| LOAD RATE |
VOLTAGE | VOLT AMPERES A/P |
POWER (watts) |
PART NO. |
| 35-AMP | 120VAC | 25.6 | 14.0 | 425NO-120A |
| 24VDC | 13.2 | 13.2 | 425NO-24D | |
| 240VAC | 24.8 | 15.2 | 425NO-220A | |
| 60-AMP | 120VAC | 23.2 | 11.6 | 460NO-120A |
| 24VDC | 13.2 | 13.2 | 460NO-24D | |
| 240VAC | 23.6 | 14.0 | 460NO-220A | |
ALSO AVAILABLE:
Top Termination, Top Screw Termination (on 35 AMP units), Loads other than AC Resistive & Tungsten,
and Brackets other than Standard (on 35 and 60 AMP units)
Our mercury contactors are comparable with the following brands: ABB, ACT, Adams & Westlake, AEC, Aleph International, American Electronic, American Zettler, Amperite, ASB, ASI, ATC, CCI, Clare, Comus, Crouzet, Cougar Electronics, Dare, DME, Durakool, Eaton, Gama Electronics, Gavazzi, Gunther, Hamlin, Hasco, Leach, magnecraft, MDI, Mecury Switches, Micropac, MSI, Omega, Ogden, Panasonic, Phoenix Contact, SE Relays, Teledyne, tempco, Thermal Devices, Tyco, VB Controls, Vertex, Watlow.
TYPICAL APPLICATIONS
| LIGHTING | GENERAL APPLICATIONS | ELECTRICAL HEATERS | FOOD INDUSTRY EQUIPMENT | SPECIALTY APPLICATIONS |
| Auditorium Lighting | Air Conditioning | Baseboard Heaters | Baking Ovens | Capacitor Discharge Systems |
| Beacon & Search Lights | Alarm Systems | Blow Molding Machines | Coffee Urns | Hazardous Locations |
| Copy Equipment | Automatic Door Closures | Cabinet Makers | Deep Fryers | Mining Equipment |
| Dimmer Controls | Battery Chargers | Chemical Tank Heaters | Dishwashers | Phase Converters |
| Display Signs | Blue Print Machines | Curing Furnaces | Electric Grills | - |
| Emergency Lighting | Copiers | Drying Ovens | Electric Ranges | - |
| Flood Lights | Computer Power Supplies | Duct Heaters | Pizza Ovens | - |
| High-Intensity Lamps | Corrosive Locations | Film Packaging | Steam Generators | - |
| Hospital Lighting | Dusty/Oily Locations | Glass Furnaces | - | - |
| Lighting Test Panels | Dry Cleaning Equipment | Heat Lamps | - | - |
| Mercury Vapor Lamps | Energy Management Systems | Heat Sealing Equipment | - | - |
| Parking Lot Lighting | Incubators/Brooders | Induction Heaters | - | - |
| Photography Lighting | Low Voltage Switching | Industrial Ovens | - | - |
| Scoreboards | Marking/Engraving Equipment | Infrared Heaters | - | - |
| Sodium Vapor Lamps | Motor Starting | Ink Drying/Heating | - | - |
| Stage/Theater Lighting | Soldering Equipment | Injection Molding Machines | - | - |
| Street Lighting | Surgical Equipment | Kilns | - | - |
| Surgical Lighting Control | Telephone Switching | Lab Ovens | - | - |
| Tower Lights | Test Panels | Packaging Equipment | - | - |
| Traffic Signals | Vapor Degreasers | Plastic Extruders | - | - |
| Tungsten Lamps | X-Ray Machine Controls | Pool Heaters | - | - |
| - | - | Quartz Heaters | - | - |
| - | - | Radiant Heaters | - | - |
| - | - | Roof Top Heating | - | - |
| - | - | Shrink Tunnels | - | - |
| - | - | Unit Heaters | - | - |
| - | - | Vacuum Forming | - | - |