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MDI mercury contactors/relays are durable and float switches and liquid level controls for water and sewage Liquid Level Control Floats
Contactors and Solid State Relays,
Tilt, Tip-over and Proximity Switches
Motion and Shock Sensors.
MDI Mercury Displacement Industries Relays, Contactors, Liquid Level Control Floats, Tilt and Tipover switches
Relay, Vertical, Liquid Level Control Floats, Tilt and Tipover switches
Installation Guide


* Float Drawings * Price quote form *
* Downloadable Installation Guide * Go Back *



Double Throw


Double Throw hook up
Black is common

Red is Normally Open (Pump Down)

White is Normally Closed (Pump Up)





Typical Normally Open Application

(PUMP DOWN)

Fig. 1


  1. Attach cord, using a cable tie, to any convenient rigid surface as illustrated. This is known as the tether point. Do not tighten until both turn-on and turn-off levels are established.
    (See Fig. 1)
  2. To adjust greater distance between turn-on and turn-off, increase cord length between tether point and float. For less distance between turn-on and turn-off decrease cord
  3. Make sure the float is at least 2 inches above pump base, in the turn-off position, before tightening cable tie at the tether point.
  4. Plug piggy-back switch cord (Currant Tap) into grounded outlet, then plug into piggy-back switch cord, and check for proper operation.


Typical Normally Closed Application

(PUMP UP)

Fig. 2
  1. Attach cord, using a cable tie, to any convenient rigid surface as illustrated. this is known as the tether point. Do not tighten until both turn-on and turn-off levels are established.
    (See Fig. 2)
  2. To adjust for greater distance between turn-on and turn-off; Increase cord length between tether point and float. For less distance between turn-on and turn-off, decrease cord length.
    (See Charts; Fig. 3 & 4)
  3. Make sure levels are correct, and that the float moves freely with no obstructions, then tighten cable ties.


NOTE: To prevent motor burnout make sure turn-off level is at least 2 inches minimum or more above the base.



Fig. 3



For CPE Cord
(16-2 SJOW)

Refer to Fig. 1



Fig. 4

For PVC Jacketed Cord
(16-2 SJTW)

PVC Jacketed Cord is subject to changes due to temperature. This chart is based on 68 F. when using PVC jacketed wire, established pumping range at room temperature.

For Liquid Level Control Floats, Contactors and Solid State Relays, Tilt, and Tipover contact MDI TODAY!

* P. O. Box 710 * 25028 U.S. 12 East * Edwardsburg, Michigan * 49112 *
* PH. (269) 663-8574 * FX. (269) 663-2924 *
* Toll Free US and Canada (800) 634-4077 *