Film ID: YFA 4615 OPERATING `SO-HI' c.1972 Visitor TabsDescription This film is part of the C.H. Wood collection and demonstrates how to use an Oil Circuit Breaker Unit. There are shots of the man draining and earthing the machine as well as showing the safety features of the machine. Title-Operating `So Hi' There is an opening shot of the So Hi Oil Circuit Breaker Unit which the voiceover says is designed for easy, safe use. A man demonstrates how to charge, turn off and on specific sections through the use of a single leaver and some switches. The voiceover mentions how to trip the unit and also how to remove one section of the unit for positive isolation. The man presses a leaver with his foot and then pulls out the lower, front portion of the unit to reveal the automatic feeder and bus bar shutter; he demonstrates how to lock them for safety. The man uses a wrench to show how to maintain the bolts on the unit. He then lifts up the lid, unlocks the bolts on the unit inside, and removes it entirely and leaves it draining on the side of the unit. The man then replaces the unit and locks it in the same way that he opened it. Next the man demonstrates how to use the So Hi `Earthing and Testing' device. He attaches a large metal item onto the back of the main piece that he removed and he pushes it back into the main unit and unlocks the trip switch. He comes back later on and removes the section; it leaves the `Earthing and Testing' device in the unit. He then carries out a series of tests on the unit, removes the testing device and replaces the unit to its original state. Title-Yorkshire Switchgear.