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Mercury (Hg) Relay - 35 AMP - Single Pole - 24V Coil - T-Top - Car Wash Vacuum


Price: $56.99

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.

The T-Top version of the 35-AMP normally open contactors are designed and manufactured to the same high quality specifications as the standard 35-AMP models. The contactor switch is the same well proven design that has been manufactured since 1975. The mounting centers and physical size are identical to the standard single pole 35-AMP molded versions. The T-Top design provides a top mounting for both line and load. It is available in the single, two & three pole models. Noted are the typical specifications and UL and CSA file numbers.

35NO-24ATH (Gen Purpose) SpecSheet

Weight: 0.9 lb
Stock Quantity: Made to Order

Delivery: Ships in 3-5 Business Days

10 to 24
25 to 49

This product contains mercury.
Please click to check if you are in IMERC compliance.

IMERC State Restrictions'

Due to mercury-added products being banned or phased out in some states, MDI cannot ship Mercury added products (Relays, Switches and Floats) to the following IMERC states:
Connecticut (CT), Minnesota (MN), Maine (ME), Massachusetts (MA), New Hampshire (NH), New York (NY), Rhode Island (RI), or Vermont (VT)
These states belong to the Interstate Mercury Education and Reduction Clearinghouse (IMERC) group, which have these restrictions.
Any order containing Mercury shipping to any IMERC state will be rejected and refunded.

  • Coil Data
    • 50 Ω
    • 242 mA
    • 5.8 VA
    • 2.9 Watts
    Coil: 24V 50/60 Hz
  • Contacts:
    • 35 AMP @ 480 VAC Resistive or General Purpose
  • Contact Resistance: .003 ohm
    • After Cycling Under Load
    Torque Specifications
    • Coil Screws: 7 in-lb
    • Terminal Screws: 31.5 in-lb
  • Coil Terminals: #6 Binding Head Screws
  • Load Terminals: 6-14 AWG
  • Operate Time: 50 milliseconds
  • Release Time: 80 milliseconds
    Dielectric Withstand: 2500 VAC RMS
  • Longevity: Millions of Cycles
  • Temperature Range: -35°C to 85°C
  • AC Resistive
    • 240 VAC @ 35 AMPS
    • 480 VAC @ 35 AMPS
  • AC Inductive
    (P.F. 0.4 or Greater)
    • 120 VAC @ 25 AMPS
    • 240 VAC @ 15 AMPS
  • General Purpose
    (P.F. 0.7 or greater)
    • 240 VAC @ 35 AMPS
    • 480 VAC @ 35 AMPS
  • DC Resistive Heating
    • 48 VDC @ 60 AMPS
    • 125 VDC @ 16 AMPS
    • 250 VDC @ 12 AMPS
  • Tungsten Lamp
    • 120 VAC @ 35 AMPS
  • Motor Loads
    • Single Phase
      • 120 VAC @ 2 H.P.
      • 240 VAC @ 3 H.P.
    • Three Phase
      • 240 VAC @ 5 H.P.
      • 480 VAC @ 7.5 H.P.

Made in the USA

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Since 1975, MDI
Quality - Durability - Reliability

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Non-Mercury Alternatives

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.

The load terminals are isolated from each other by the glass in the hermetic seal. "The plunger assembly", which includes the ceramic insulator, the magnetic sleeve and related parts, floats on the mercury pool. When the coil is powered causing a magnetic field, the plunger assembly is pulled down into the mercury pool which is in turn displaced and moved up to make contact with the electrode, closing the circuit between the top and bottom load terminal, which is connected to the stainless steel can. For constant duty applications, a return spring is used in place of the buffer spring.

Mercury to Metal Contactor Illustration

Mercury to Metal Contactor Illustration

While MDIs 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.

For more information, please click here.