1、 Product Overview:
The OW-NPEX series safety barriers are connected to various domestic and imported two - and three wire transmitters, current sensors, temperature measuring elements, and other instruments, and are used as associated equipment for safety and explosion-proof systems. Widely used in safety and explosion-proof systems for intrinsically safe instrument products in chemical, oilfield, metallurgical, natural gas, power and other industries.
The OW-NPEX series safety barrier is used to isolate and transmit single or dual channel current or voltage signals from hazardous areas to the safety zone. The intelligent safety barrier has an online fault self diagnosis function. Users can set the input signal type and output range of this product through a dedicated handheld Chinese programmer, and perform serial communication networking in the safety zone through the configured communication interface.
2、 Characteristics of safety barriers:
1. No external power supply is required, it can be directly used in 4-20mA circuits.
2. Low power consumption and low cost.
3. Can isolate primary instruments such as transmitters with 4-20mA
4. Support Hart communication
5. Adopting a three party isolation method, there is no need for a system grounding line.
6. The requirements for instruments in hazardous areas have been significantly reduced, and there is no need to use isolated instruments on site.
7. Isolated safety barriers have stronger input signal processing capabilities and can accept and process signals from thermocouples, thermistors, frequencies, and other sources.
8. The isolated safety barrier can output two signals that are mutually isolated, providing them to two devices using the same signal source, ensuring that the signals of the two devices do not interfere with each other, and improving the electrical safety insulation performance between the connected devices.
3、 Safety barrier parameters:
Input signal: 4-20mADC, distribution voltage 18.5V-28.5VDC
Output signal: 4-20mADC (load resistance ≤ 500 Ω) or 1-5VDC (load resistance ≥ 250K Ω)
Basic error: ± 0.2% FS
Explosion proof mark: [Exib] Ⅱ CT6
Explosion proof rating: 220V (AC/DC)
Rated value of intrinsic safety circuit: maximum open circuit voltage ≤ 30V, maximum short-circuit current ≤ 30mA
Power consumption: ≤ 2W
Power supply voltage: 24VDC ± 5%
Temperature drift: ≤ 0.01% FS/℃
Environmental temperature: 0-50 ℃
Relative humidity: ≤ 85% RH
Working environment: frequency ≤ 25Hz, vibration amplitude (double) ≤ ± 0.1mm, external magnetic field ≤ 400A/M, no corrosive gases or impurities around
Installation method: Rear mounted card (DIN35 track) or rack mounted
4、 Selection of safety barriers:

Model number					Explanation
NPEX					LCD detection end safety barrier Thermal resistance input
Channel					Default is single channel
	D				Dual input channel
First output		1			4-20mA
		2			1-5V
		3			0-10mA
		4			0-5V
		5			0-10V
		6			0-20mA
		7			1: 1 Resistance signal output
second output					Default no second output
			1		4-20mA
			2		1-5V
			3		0-10mA
			4		0-5V
			5		0-10V
			6		0-20mA
Communication and alarm functions (if this option is selected, there will be no second output function)					Default is no communication function
				T1	485 communication (single output only)
				T2	232 communication (single output only)
				A1	Alarm relay output (single output only)
				A2	Alarm relay output (dual output)

The following figure shows the safety barrier at the single in and single out inspection end