VariSTAR Type Composite Light-duty Under-oil (CLU) MOV Arrester


The Cooper Power Systems VariSTAR Type CLU Under-oil MOV arrester is designed in accordance with IEEE Std C62.11™ standard light duty distribution class requirements. It is designed for either horizontal or vertical mounting inside the distribution transformer tank to eliminate the difficulties associated with externally mounted arresters.

Catalog Number CLU
Commonly Applied Voltage Rating Refer to Catalog CA235023EN
Protective Characteristics Refer to Catalog CA235023EN


  • The CLU Arrester design features a fail open or fail short option. The fail open version utilizes an isolation link as illustrated in Figures 3 and 4 on page 2 of Catalog 235-95. Since the isolation link is external of the arrester components, no components will be expelled into the transformer tank upon operation. The time-current characteristic curve is illustrated in Figure 5 in Catalog 235-95. The fail short version does not include the isolation link and will remain intact upon operation.
  • Rigid mounting plates for a stronger mounting configuration.
  • The CLU Arrester is compatible with mineral oil and Envirotemp FR3 fluid.
  • The fiberglass-reinforced epoxy composite acts as a seal against all fluids; protecting the active components within the module.