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Teamwork Restores Beam in SPEAR3

(Photo - SPEAR3) Thanks to SLAC teamwork, a problem with a high voltage power supply for the SPEAR3 booster RF system was rapidly addressed last week. SSRL is indebted to all who helped facilitate the repair.

Although the exact nature and severity of the problem were not readily apparent at first, the SSRL Electrical Systems and Mechanical Services groups planned for various scenarios to make anticipated repairs. Once it was determined that the power supply needed to be replaced, activities were closely coordinated with the rigging crew (CEF) to extract the supply from its storage space in PEP Region 12 and with the SSRL facilities group who quickly arranged for a contractor to take down a wall in Building 140 in order to access the failed power supply.

Removal work was temporarily halted when an unidentified odorous gas was detected upon opening an oil inspection access port for the supply. The Industrial Safety group (ES&H) analyzed the gas and found it to be flammable, so work recommenced only after the gas had safely dissipated.

The spare supply was installed by the evening of March 8 and was left overnight to allow bubbles in the newly added insulating oil to escape. Electrical testing commenced on Thursday morning, but only after a special effort was made to liberate the variable voltage transformer (VVT) test cart from behind the jammed roll-up door to the PEP Region 2 storage area.

With SSRL users anxiously waiting for beam, those responsible for the VVT (building and labor pool, including the Capitol Equipment Project, PEP II/Accelerator Systems and CEF) quickly agreed that the VVT needed to be extracted as soon as possible, even if it meant cutting a hole in the rolling door. As it turned out, the jammed door could be opened just enough with the aid of a forklift to liberate the VVT test cart, and the power supply testing was carried out successfully.

After one last hurdle involving the update of a circuit breaker arc flash hazard label, which was quickly accommodated, the booster RF system was turned on and SPEAR3 beam was re-delivered to users on Thursday afternoon, March 9th.

SSRL is indebted to all who participated in the replacement of the RF power supply and is grateful for the close cooperation of the SLAC groups that facilitated the repair.

—Bob Hettel and Ed Guerra
    SLAC Today, March 17, 2006