The Oberon Flashbarrier Arc Suppression Blanket is a Voltage Rated product intended for use by trained personnel to aid in the safe handling of potential Arc Flash hazards. The blanket is placed to form a barrier between the electrician and the hazard to redirect the explosive energy from an Arc Blast. Oberon offers two blankets: 15 KA and 25 KA. Without an agreed upon industry standard for testing blankets, Oberon developed the method outlined below.
Oberon's testing method used in the development of the Flashbarrier Arc Suppression Blanket consists of the following:A 750 KCMIL cable with a 3mm splice, supported horizontally 2' off the floor on brackets and was placed 6" away from a solid vertical wall. The blanket was mounted parallel to and 12" from the back wall, with the splice 6" from the back surface of the blanket. The blanket is held in place by straps with adjustable brackets.
To create the fault, a sheetrock screw was screwed into the splice and a ground wire connected to the protruding screw. The cable was energized with 13 KV with a fault current of 7000A clearing time of 8 cycles.
The purpose of the test is to ensure that the multiple-layered arc suppression blanket redirects the energy (thermal and blast) to the sides and up – not out toward the individual. The blanket must not allow the thermal energy to burn through all layers. It must also not have particles of the splice and molten metal penetrate the blanket. Most of the damage to the blanket is in the general area of the splice, a circle 6"-12" in diameter.
The 15 KA blanket is constructed of non-combustible material. It will not ignite and burn even if flame is applied directly to the fabric. Oberon is the only company that offers a blanket from non-combustible fabric.
The 25 KA blanket is primarily made of FR Aramids. Aramids will burn only as long as there is a source of ignition, i.e., flame from arc or burning pieces of insulation.
Blankets are hung between a potential arc source and the worker or equipment to be protected. To prevent the force of the arc going downward (toward the floor and redirected up to the individual), the lower portion of the blanket can be formed in a J under the arc source and toward the wall so the arc will be deflected upward. Never wrap a blanket around a splice. The explosive force of the air expanding (the volume of air increases as it heats up) and metal vaporizing cannot be contained by the strength of even Kevlar. The force must have someplace to go. The blanket's purpose is to redirect the force, not absorb it.
Store the blanket in its storage bag to keep it clean and out of sunlight.