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"BRI" intrinsically safe isolation unit

"BRI" intrinsically safe isolation unit


The BRI unit is a stationary continuously operating device with intrinsically safe inputs. It is designated for operation in emergency protection, alarm, and control systems of industrial facilities producing explosion- and fire hazardous products.

The BRI unit provides intrinsic safety of input electrical circuits with "ib" explosion protection category. It is intended to receive signals from serial gages with a contact output. The climatic version of the BRI unit is UHL (boreal), location category 4 as per GOST 15150-69, but for a temperature range from +5 to +40°C


The BRI unit (Figure 1) consists of: the front panel, the frame, and two side walls. The frame is covered from two sides by side walls. The front panel is fixed to the front edge of the frame and has a "POWER ON" LED. The rear frame wall has an output terminal, INTRINSICALLY SAFE CIRCUITS input terminal, and a redundant grounding clamp.

The BRI unit front panel has holes for mounting onto a switchboard as well as a screw with a seal cup for control purposes. The BRI unit is designated for providing intrinsic safety for input circuits of communication lines with contact gages by way of galvanic isolation of input intrinsically safe circuits from non-intrinsically safe power circuits and gage signal transfer output circuits.

Technical Data:

Basic parameters and specifications
Number of "intrinsically safe input – intrinsically safe output" channels
Input intrinsically safe circuit parameters:
- DC voltage on open contacts of the intrinsically safe circuits, V max.
- Short circuit current in the intrinsically safe circuit, mA max.
- Type of gage input signal
closing contact
- Overall resistance of the intrinsically safe circuit communication lines and the closed gage contact, kOhm, max.
- The intrinsically safe circuit communication line electrical capacitance and inductance correspondingly, not more than, Cmax µF and Lmax, mH
0.3 and 1
Output signal parameters
- Optocoupler photodiodes power supply voltage, V max.
- Max. output current, mA, max.
AC power supply:
- Voltage, V
- Frequency, Hz
Consumed power, V · A max.
BRI overall dimensions, mm max.:
- Height 
- Width
- Depth
BRI weight, kg
Service life, years min. 
Warranty period, months