TWI-22-TB(1992): Loop-Powered Two-Wire 4-20mA Conditioner/Isolator  specsheet

  • High Input-Output-Power Isolation (1500VAC Test)
  • Small Size - Fits on Terminal Block Rail
  • Industry Standard 4-20 mA Input
  • Industry Standard 4-20 mA Output
  • Loop-powered from Input Loop, no Additional Power Supply Required
  • Drive up to 700 Ohms on Output Loop
  • Only 1.5 Volts Loss on Input Loop
  • High Noise Rejection
  • CSA and NRTL Approved (LR 51078)

The TWI-22-TB (1992) is a loop powered current isolator which can be used in applications where loop isolation is required but power is not available and/or space is limited. The isolation is achieved via an isolation transformer. Every isolator is tested at 1500 VAC to ensure that the dielectric strength is sufficient.

The output is capable of driving a load of 700 Ohms while only an additional 1.5 Volts are dropped across the input. For example, an output loop load of 250 Ohms would result in a total input impedance of: R(load) + R(isolator), where R(isolator) = 75 Ohms

  • Isolation: Input to Output to Power 1500 VAC (test)
  • Input: 4-20 mA
  • Output: 4-20 mA
  • Accuracy/Linearity: +/-0.1% max., +/-0.05% typ.
  • Response Time: 10 msec to 63% of final value, 40 msec to 99% of final value
  • Operating Temperature: -40 Deg.C. to +50 Deg.C.
  • Temperature Effects: +/-0.1% max., +/-0.05% typ. (for 40 Deg.C. change)