Safety Barriers

I. Overview

● The LU-A11 safety barrier can supply power to field transmitters, limits hazardous energy from entering the hazardous location through the intrinsically safe terminals, and converts DC signals into isolated standard process signals.

● Linearized with temperature (thermocouple, RTD).

● Powered by an independent power supply, with isolation between power supply, input and output.

II. Technical specifications

● Input parameters (hazardous area signals)

Current input  Input range: DC 4~20 mA, 0-20mA, 0-10mA

Distribution voltage: ≥16 VDC

Input resistance: built-in input resistor 50Ω

Voltage input  Input range: 1~5V, 0~5V, 0~10V

            Input resistance: ≥500kΩ

Thermocouple input (millivolt signal), input range:

Minimum millivolt span: 3mV

RTD input, input range:

Permissible lead resistance : ≤5Ω (identical for the three wires)

● Output parameters (safe area signals)

For current output  Output range: DC 4~20 mA, 0-20mA, 0-10mA

Permissible load: ≤350Ω

For voltage output  Output range: DC1~5V, 0-5V, 0-10V

Output impedance: ≤500Ω

● Intrinsic safety parameters

     Linear current/voltage                   Thermocouple/RTD

Explosion-proof marking: [Exia] ⅡC           Explosion-proof marking: [Exia] ⅡC

  Maximum permissible voltage Um: 250V         Maximum permissible voltage Um: 250V

  Maximum output voltage Uo: 28V           Maximum output voltage Uo: 12V

Maximum output current Io: 93mA          Maximum output current Io: 24mA

● Ambient parameters

Power sup ply: 20-30VDC

Ripple factor below 10%P-P, approx. 1W 

Power indicator lamp: green LED, lit when the power is supplied

Operating temperature range: -20~ +60°C

Operating humidity range: 0 ~ 95%RH (non-condensing)

● General technical parameters

Standard accuracy for linear input: ±0.1% , accuracy for thermocouple/RTD input: ±0.2%

Temperature drift: ±0.015%/°C

Response time: ≤10mS

Isolation strength: 1.5KV, 1min, 50HZ between input, output and power supply

Insulation resistance: input-output-power supply ≥100MΩ/500VDC

Effect of load resistance variation: ±0.1%/250Ω (for current output)

                   ±0.1% (for voltage output)

Power-on stabilization time: ≤3s