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Unit Diagnostics

The failure alarm option for the VS5100 VERSA-SWITCH consists of a separate electronic circuit board that monitors critical functions of the VERSA-SWITCH on a continuous, real
time basis. This “watch dog” circuitry initiates an output alarm trip on channel two should a malfunction occur in any of the following:
  • Sensors
  • Field Wiring (remote)
  • Sensor Excitation Electronics
  • Sensing & Signal Conditioning Electronics
  • Power Supply Regulator
  • Electrical Power Source

In normal operation, the channel two relay contacts are open and three yellow LED’s are illuminated indicating an “Alarm Ready” status.
If a failure occurs, the failure alarm relay contacts will close and one or more of the yellow LED’s will be extinguished. The combination of “Off” and “illuminated” LED’s will provide an indication of the probable malfunction.
The failure alarm is a factory installed option. If you need a failure alarm option installed in an existing VERSA-SWITCH the electronics must be returned to the factory for upgrading.
This option is not available for the microtuf® line of DELTA M switches.

  • Simple field adjustable thermal differential switch for mass flow or level of liquids or gasses with Unit Diagnostics and time delay from 0 to 300 sec.
  • Wide operating temperature range -100°F to +850°F (-70°C to +458°C).
  • User configurable operating power 110VAC, 220VAC, or 24VDC.
  • Can be configured with 2 independent outputs, such as level or mass flow with a “Watchdog” circuit should a problem occur.
  • Level response time of .1 to 1 second on wetting, media dependent
  • Flow response time of .5 to 10 seconds, media dependent
  • Can be used for either gas or liquid applications.
  • Two Year Workmanship Warranty



Thermal Differential, dual RTD sensors with no separate heater

Process Connection:
Standard 0.75 inch MNPT
Optionally 0.5 inch and larger MNPT and various other process connections such as sanitary and flanges

Insertion Length:
Standard 2.0 inch
Optionally 0.5 inch or greater

Operating Temperature Range:
Standard -100°F to 390°F (-70°C to +200°C)
Medium Temperature to +572°F (+300°C)
High Temperature to +850°F (+458°C)

Materials of Construction:
Standard 316L Series Stainless Steel
Optionally Hastelloy, Monel, Inconel and other exotic materials

Operating Pressure Range:
Standard to 3000 psia (207 bar)


Standard Field selectable 110VAC, 220VAC, or 24VDC at 3 watts (No heater power required) Optionally 24VAC

Operating Temperature Range:
Standard -40°F to +140°F (-40°C to +60°C)
Optionally Remote electronics for use in medium and high temperature environments

Independent primary relay DPDT and secondary relay SPDT, contacts rated at 5 amp, 250 VAC with fail safe capability; built in time delay 0 to 300 seconds for each channel.

Integral and automatic during power up.

Failure Alarm:
Continuous monitoring circuit to alarm should a failure condition of any sensor, component, wiring, or power occur. (Occupies second channel)

Explosion proof; NEMA 3, 4, 4x,7, and 9; CSA, FM, UL


Operating Range:
Flow 0.01 to 5.0 fps in oil,2.5 fps in water and 0.1 to 500 fps in gases. Level change as small as .03 inch.
Temperature -70° C to +458° C +/- 1° C.

Response Time:
Media dependent 0.5 to 10 seconds.

Available Approvals:
CSA Class 1 Div. 1 Groups B,C,&D Class 2
Div. 1 E,F,&G with T4A Temp rating.