MDI Mercury Relays

• GENERAL INFORMATION

• FEATURES

• TYPICAL APPLICATIONS

• DESCRIPTION

• 30-AMP Normally Open Contactors

• 35/60-AMP Normally Open Contactors

• 100-AMP Contactors

• High Voltage Contactors

• COIL DATA

• Proper Fusing is Required

GENERAL INFORMATION

Mercury Displacement Relays are all designed and built to meet the most exacting demands of industry.  They 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.  They have proved 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.

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 required 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.

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.

FEATURES

1) ADVANTAGES OVER ELECTROMECHANICAL AND SOLID STATE RELAYS
    A)  Superior Performance and Reliability
        (a)  Long life
        (b)  Durable
    B)  Compact Size
    C)  Low, Predictable Contact Resistance
    D) Reduced RFI for Improved Interface Capability
    E)  Handles a Variety of Loads
        (a)  Increases design flexibility
    F)  Rapid On-Off Cycling Capability
        (a)  Mercury quickly dissipates contact heat
    G)  Low Coil Power Requirements
    H)  Minimal Derating Due to Higher Ambient Temperatures
    I)  Quiet Action

2)  DESIGN & CONSTRUCTION
    A)  Contacts are within a hermetically sealed steel body
        (a)  Impervious to adverse conditions
        (b)  No external arcing
    B)  Arcing is in a gaseous atmosphere
        (a)  Quenches the arc
        (b)  Extends relay life
    C)  Only one moving part (the plunger)
        (a)  No buttons to pit, weld or burn out
    D)  One coil for each set of contacts
        (a)  Assures consistent switching
        (b)  Minimizes pull-in variation between contacts
    E)  Epoxy encapsulated
        (a)  Moisture resistant
        (b)  High dielectric strength
        (c)  Permanently fixes contacts to coil; eliminating possible misalignment
        (d)  Helps dissipate heat and noise
        (e)  Rugged (impact resistant)

3)  BENEFITS
    A)  Reduction of Operational and Maintenance costs
    B)  Increases Utilization and Productivity of Equipment
        (a)  By reducing down-time
    C)  Installation and service is a routine operation
        (a)  Simple to install
        (b)  No sophisticated equipment is required
        (c)  Easy to trouble-shoot

TYPICAL APPLICATIONS
FOR MDI'S MERCURY DISPLACEMENT CONTACTORS

LIGHTING

FOOD INDUSTRY EQUIPMENT
(HEATERS)

DESCRIPTION

• On Normally Open Units:  Operate Time:  50 milliseconds
                                                 Release Time:  80 milliseconds

• Contact Resistance:  30-AMP = .003 ohm*

• Dielectric Withstant:  2500 Vac Rms

• Longevity:  Millions of Cycles

• Temperature Range:  -35 degrees C to 85 degrees C

• Coil Terminals:  #6 Binding Head Screws

• Load Terminals:  #8 Binding Head Screws

• UL Listing:  File #E62767

• C.S.A.:  File #LR41198

Coil Data

RATINGS
(Ratings are in amps unless otherwise specified.)

• On Normally Open Units:  Operate Time:  50 milliseconds
                                                 Release Time:  80 milliseconds

• On Normally Closed Units:  Operate Time:  30 milliseconds
                                                    Release Time:  35 milliseconds

• Contact Resistance:  35-AMP = .003 ohm*
                                       60-AMP = .002 ohm*

• Dielectric Withstand:  2500 Vac Rms

• Longevity:  Millions of Cycles

• Temperature Range:  -35 degrees C to 85 degrees 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

• UL Listing:  File #E62767 for 35 and 60-AMP N.O. Units 1-4 Poles

• C.S.A.:  File #LR41198 for 35 and 60-AMP N.O. Units (Heater Loads) 1-3 Poles

• Auxiliary Devices for Use in Hazardous Locations.  UL File #E71867 N.O. Units Approved for Class 1, Groups A, B, C and D, Division 2 Only.  To Order for Hazardous Locations, Add the Suffix -X to Part Number.

RATINGS
(Ratings are in amps unless otherwise specified.)

• On Normally Open Units:  Operate Time:  50 milliseconds
                                                 Release Time:  80 milliseconds

• On Normally Closed Units:  Operate Time:  45 milliseconds
                                                   Release Time:  60 milliseconds

• Contact Resistance:  .001 ohm*

• Dielectric Withstand:  2500 Vac Rms

• Longevity:  Millions of Cycles

• Temperature Range:  -35 degrees C to 85 degrees C

• Coil Terminals:  #6 Binding Head Screws

• Load Terminals:  Pressure Connectors.  Standard Accepts A.W.G. #2 to #12.  For A.W.G. #1 to #8, Add Suffix -5 to Catalog No. (i.E. 100NO-120A-5)

• Ratings:  Derate over 240 Vac Res.

RATINGS
(Ratings are in amps unless otherwise specified.)

High Voltage Contactors
For UV Curing, and Various High Voltage applications.   Available in Single Pole, Normally Open, and Normally Closed Units.  The coils utilize 6-32 Wire Binding Screws, and the Contacts use Compression type terminals for #4 thru #14 AWG wire.
Ratings are:  10 Amps @ 3500 Vac
                   15 Amps @ 2500 Vac
                   AC Inductive - Power Factor .7 or Greater

Coil Data

COIL DATA
PER POLE RATINGS ON STANDARD COILS

Proper Fusing is Required
1.  While MDI's contactors handle high inrush, such as lamp loads, very well, mercury contactors are susceptible to damage by short circuit currents, and should be fused to minimize short circuit fault currents.  Fast acting UL class RK-1 and class J fuses and semiconductor I2t fuses more effectively protect relays than other fuses.  These are low-peak fuses designed to limit short circuit currents.  Regardless, when there is a short circuit, relay operations should be closely monitored afterward because of the possibility of concealed damage that could cause the relays to behave inconsistently.

                                                   RECOMMENDED
                                       250VOLT                  600VOLT
                                         KTN-R                      KTS-R
                                       JJN/A3T                         JJS
                                                                         JKS/A4J
                                                                          KTK-R

2.  Mercury Displacement relays must mount vertically +/- 10 degrees.
3.  Control line can be protected with metal oxide varistors (MOV).  Use suffix -11.
4.  Disconnect power before installing or servicing.  Observe all electrical and safety codes and ordinances such as National Electrical Code (NEC) and the Occupational Safety and Health Act (OSHA).