651T/652T Multi-Channel, Two-Wire Isolators by Acromag

Companies & Organizations:

United States of America

Acromag, Incorporated
30765 South Wixom Road
Wixom, Michigan 48393-2417 USA

651T: Single I/O channel

652T: Dual I/O channel


These units convert a 4-20mA process current input into two identical isolated 4-20mA output signals. Each channel operates independently and is isolated from the others to prevent interaction between channels.


For easy troubleshooting, each unit has LEDs and diagnostic test points. Power LEDs help identify output open loop conditions. The precision 10-ohm sense resistor enables monitoring of the output signal without disturbing field wiring.


Input / Output Ranges: 4 to 20mA DC input; 4 to 20mA DC output


Power Requirement: 12 to 36V DC (loop-powered) Two-wire transmitter


Approvals: CE marked. UL, cUL listed Class I, Division 2, Groups A,B,C,D.


Performance Specifications


Reference Test Conditions: Input/Output current: 4 to 20mA; output load 500 ohms; 77°F (25°C).

Input range: 4 to 20mA input (each channel).

Input burden: Voltage drop Less than 1.5V, typical (75 ohm equivalent).

Output range: 4-20mA DC output (each channel). Rl = (Psupply-12V) / 0.02.

Output compliance: Psupply = 12V + (0.02 x Rload).

Output limiting: Outputs are limited to 36mA.

Output ripple: Less than ±0.1% of the maximum output span.

Accuracy: ±0.1% of output span. Error includes the combined effects of isolator repeatability, hysteresis, terminal point linearity and adjustment resolution.

Ambient temperature effect: Less than ±0.006% of input span per °F (±0.01% per °C) over the ambient temperature range for reference test conditions. This specification includes the combined effects of zero and span over temperature.

Calibration: Two 15-turn potentiometers (zero and span) per channel, accessible from front of the unit.

Bandwidth: -3dB at 45Hz, typical.

Response time: For a step input, the output reaches 98% of output span in 15mS, typical.

Noise rejection: Common mode, 100dB at 60Hz, typical; Normal mode, -5dB at 60Hz, 100 ohm source, typical.

Diagnostics: LED power indicator: Off for output open loop detection, power, or load compliance problem.

Field test points: An internal 10 ohm sense resistor provides test points for monitoring the output signal current during field maintenance.





Ambient Temperature: Operating: -25 to 70°C (-13 to 158F). Storage: -40 to 85°C (-40 to 185°F).

Relative Humidity: 5 to 95%.

Power Requirement: 12 to 50V DC for each output channel.

Isolation: Inputs, outputs, and individual channels are isolated from each other for common-mode voltages up to 250V AC, or 354V DC off ground, on a continuous basis (will withstand 1500V AC dielectric strength test for one minute without breakdown).

Radiated Field Immunity (RFI): Complies with EN61000-4-3 Level 3 (10V/m, 30 to 1000MHz) and European Norm EN50082-1.

Electromagnetic Field Immunity (EMI): Less than ±0.25% of output span effect under the influence of electromagnetic fields from switching solenoids, commutator motors, and drill motors.

Surge Immunity: Complies with EN61000-4-5 Level 3 (2KV) and European Norm EN50082-1.

Electrical Fast Transient (EFT): Complies with EN61000-4-4 Level 3 (2KV) and European Norm EN50082-1.

Electrostatic Discharge (ESD): Complies with EN61000-4-2 Level 3 (8KV air, 4KV direct to the enclosure port) and European Norm EN50082-1.

Radiated Emissions: Meets or exceeds European Norm EN50081-1 for Class B equipment.

Approvals: CE marked, UL & cUL listed. Hazardous Locations: Class I: Div. 2; Groups A, B, C, D.





Enclosure: Case: Self-extinguishing NYLON type 6.6 polyamide thermoplastic UL94 V-2 NEMA Type 1 enclosure.

Connectors (Removable Terminal Blocks): Wire Range: AWG #14-22 (AWG #12 stranded only).


Printed Circuit Boards: Military grade FR-4 epoxy glass circuit board.

Dimensions: 1.05W x 4.68H x 4.35D inches. 26.7W x 95.3H x 110.5D millimeters.

Shipping Weight: 1 pound (0.45 Kg) packed.



Features & Benefits


Two channels in a single unit saves space and reduces costs.

Signal splitter model (653T) provides two identical outputs from one input signal.

Galvanic isolation eliminates ground loops, reduces noise, and blocks transient signals.

Independent channels prevent signal interaction and offer spares for later use.

Power LEDs provide a visual indication of operational process loops.

Excellent accuracy and stability ensure reliable

Defense Products & Services: 651T/652T Multi-Channel, Two-Wire Isolators by Acromag
Companies & Organizations: 
Defense Products & Services Sectors: Computers components
Description: 651T/652T Multi-Channel, Two-Wire Isolators
Source of Information: Acromag Inc