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Power Supply Unit

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BS 9120

Product Description and Application
The power supply unit BS 9120 (as intrinsically safe power supply within a firedamp-proof enclosure or as flange-mounted intrinsically safe power supply unit) - in connection with power supply units of type SVI-12-1400-xx - serves for the power supply of intrinsically safe equipment and systems.
 
The length of the connecting leads is optional, however, it will have to be verified once again in connection with the approval of the plant.
 
Type of explosion protection: mining Ex I M2 EEx em [ib] I
Degree of enclosure protection IP 65
EC type examination certificate IBExU 99 ATEX 1016 X
Ambient temperature -20 °C to +55 °C (with power supply unit SVI-12)
Design - Technical Specifications
Inside the outer casing of the power supply unit one or several power supply units SVI-12-1400-xx (each inside its own certified enclosure) are installed.
 
The power supply unit essentially consists of a non-intrinsically safe primary regulator (DC/DC-converter) and an intrinsically safe secondary regulator.
 
In all versions the incoming and outgoing cables are conducted through openings in the lateral walls with grommets or with stuffing glands. The live parts are either insulated by a 1 mm thick hard paper plate or by a 2 mm thick sealing compound layer towards the housing.
 
The printed circuit boards are completely sealed with silicone rubber having a thickness around the components of at least 1 mm. Sealing against ingress of an explosive atmosphere through the connecting leads is provided by an at least 5 mm long blank conductor path within the sealing agent.
 
Technical Specifications BS 9120
Mains voltage AC 42 to 230 V +/- 20 % or
DC 35 to 350 V
Output voltage 12 Volt +/- 2 %
Current max. 1.4 A
Max. outside inductance (at Ca = 0) 30 µH
Max. outside capacitance (at La = 0) 30 µF
Ambient temperature -20 °C to 55 °C
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