T700 Loop-Powered Isolator

Loop-Powered Isolator – T700

Product Description

T700 Loop-Powered Isolator

The T700 Loop-Powered Isolator is a loop-powered isolator that accepts a current input (typically 4-20mA). It takes its power source voltage and the output current loop drive (500 Ohm, 10V compliance, max.) from the input current loop. The 1-20mA output current follows the input current signal. Span adjustment is provided to adjust for load variations. There are two (+) output terminals. Terminal #3 is for loads less than 100 Ohms (e.g., current meter inputs) and terminal #4 is for loads greater than 100 Ohms.


The T700-0001 is designed for installation in industrial field environments. Circuitry is enclosed in the TransPak’s rugged, diecast aluminum housing which is sealed for protection against corrosion, moisture, dust and electrical noise, such as radio frequency interference (RFI) and electromagnetic (EMI) interference. Top-mounted barrier terminal strip connections are provided. Optional mounting solutions and enclosures are also available (see Accessories).


The T700 is useful in eliminating ground loop problems in existing systems, and as a preventative measure in the design of new systems. The DC current isolation allows a difference in potential of up to 1800V between the input, output signal and case ground. This isolation provides the benefits of grounded inputs without creating signal errors or ground loops.



Ranges: 1-20mA and 4-20mA, 30Vdc max.
Voltage Drop: <3V, plus output load


Common Mode Rejection

>100dB (DC to 60Hz)



  • Range: 1-20mA and 4-20mA
  • Terminal #4 Drive: 100 to 500 Ohm loads, 10V Max. at 20mA
  • Terminal #3 Drive: 0 to 100 Ohm loads, 2V Max. at 20mA
    • Note that only one (+) output terminal (either #3 or #4) can be used at a time.

Output Accuracy

  • +0.1% of full-scale typical (250 Ohm load),
  • +0.2% maximum including linearity, hysterisis and repeatability.


< 0.02%/°C of span max. for full-scale and zero



Load Regulation

< 0.1% of span, typical per 10 Ohm change, from 100 to 500 Ohms



1800Vdc, input to output to case ground

ESD Susceptibility

Meets IEC 801-2 level 3 (8kV)

Response Time

50mSec maximum, 10 to 90%


Operating/Storage: -20 to 80°C (-4 to 176°F)

25 to 95% @ 40°C, non-condensing


0.56 lb.

Agency Approvals

  • UL recognized per standard UL508, (File No. E99775).
  • CSA certified per standard C22.2, No. 0-M91, and 142-M1987, (Certificate No. 2500001267).
Ordering Information
1. Specify: Model: T700-0001
M004 Snap-in Channel Track, 4 feet.
T805 Explosion-Proof Housing.
T902 Mounting Plate for M004, includes 4″ track.
T903 Extra Retaining Ring for T805 (included in T805).
T906 Extra Mounting Plate w/slotted thumbscrews for Visipak V565C (included in V565C).
T910 Bulkhead Mounting Plate.
9046 Action Pak 24/40VDC, 65mA Power Supply.
T609 24VDC, 600mA Loop Power Supply.
V565C 3-1/2 Digit LCD Indicator, wide-ranging display, NEMA 4X Housing, Option C to house Transpak.