SCCR Testing Procedures


Our FUSION SCR power controllers have a 100kA Short Circuit Current Rating (SCCR). Here's a behind-the-scenes look at our testing procedures.

The tests were conducted at Bussman Labs, in St. Louis, MO.

The controllers passed two tests: Standard Fault, and High Fault.

For the standard fault test, fuses are calibrated to have a let-through current of the peak let-through for the recommended fuse size. The high fault test uses the recommended fuse size: fast-acting, Class T fuses.

Here is the load and shorting contactor. The metal enclosure is to be connected to the phase of the source of supply which is connected to the pole judged as having the least risk of arcing to ground.

The controller is held in a wire mesh cage sized to 150% of controller size. This simulates the minimum requirement panel size for an end user. This cage is covered in cotton mesh that is considered highly flammable. Everything is installed according to manufacturer's recommendations.

To run the test, we initiate voltage to the controller and charge up the generator to a specific level determined by the fuse size. After counting down, the short is triggered by the contactor.

The contactor, located here, is sized to allow the peak let-through current of the fuses. A smaller contacter would not provide enough let-through and would void the test.

The noise heard is the contactor closing. The flash is the arc flash of the contactor when the short is being initiated.

In order to pass the tests, controller buswork, and ground wire must remain intact. The ground wire does not open or break, and nothing in or around the controller can have burn marks showing signs of a flame.

All FUSION and Compact FUSION units have received a 100kA short circuit current rating after passing these tests.
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For more information about the rating and how SCCR impacts your business, visit, or contact the experts directly and call Control Concepts, Inc.