Solid State Relays  from Prime Controls Co.   MDI
MDI Incorporated is a well-known manufacturer of mercury displacement relays, which are great for heater contactors. However, mercury contactors have been banned in California (even as replacements) and in several other states, so MDI has designed a solid-state relay package to replace them directly. They also offer solid state relays with integrated heatsinks. The most common configurations are in stock at Prime Controls Co. Call us for more information, for quotes or to order.
Part Numbers and Prices
ssr 1 pole Solid State Relays with integrated heatsink
  • 20, 30, 50 or 70 amps, 42 - 600V
  • AC/DC or DC control signals
  • DIN rail or mounting tabs
PDF:   datasheet
2-pole ssr 2PSS60A25 Solid State Relay 2p 25A
  • Direct replacement for Mercury Contactors
  • mounts in same holes with retrofit bracket (order separately)
  • uses same control signal (20-275 VAC, 24-190 VDC)
  • 2-pole 25A with pass-through terminals for third leg
PDF:   datasheet
2-pole ssr 2PSS60A40 Solid State Relay 2p 40A
  • Direct replacement for Mercury Contactors
  • mounts in same holes with retrofit bracket (order separately)
  • uses same control signal (20-275 VAC, 24-190 VDC)
  • 2-pole 40A with pass-through terminals for third leg
PDF:   datasheet
3-pole ssr 3PSS60A30 Solid State Relay 3p 30A
  • Direct replacement for Mercury Contactors
  • mounts in same holes with retrofit bracket (order separately)
  • uses same control signal (20-275 VAC, 24-190 VDC)
  • 3-pole 30A
PDF:   datasheet
3-pole ssr 3PSS60A75/D75 Solid State Relay 3p 50A/2p 75A with Fan
  • Direct replacement for Mercury Contactors
  • mounts in same holes with optional retrofit bracket
  • uses same signal (24-275 VAC/24-50 VDC or 4-32 VDC)
  • use as 2-pole 75A or 3-pole 50A
PDF:   flyer     datasheet
bracket PM1544 Retrofit Bracket
  • Easily replace Mercury Contactors with above SSR's
  • mounts in same holes
PDF:   dimensions
For more information about MDI's products,
see them at mdius.com;
call us for quotes or to order.