Breakers

Breakers are vital to the operation of nuclear plants, providing both control and protection of electrical components, switchgear, and circuits. NLI is the nuclear industry’s leading supplier of low and medium voltage breakers through our exclusive partnership with Square D Services. This long-standing relationship is so strong, NLI has two full-time employees assigned to Square D’s Cincinnati manufacturing facility.

One of NLI’s best selling products is the Square D Masterpact® low voltage breaker, of which literally thousands are installed at numerous sites. Quickly becoming the industry standard, the Masterpact® breaker is innovative in that it requires no overhauls for 40 years (or 10,000 operations), and needs to be cycled only once every six years.  They are smaller than all legacy designs; custom cradles are designed by NLI and Square D to meet the requirements of each facility. The cradle racks into the existing switchgear without modification and the Masterpact® racks into the cradle. The only physical change required is to the door due to differences in the size of the opening.

With Masterpact® breakers, refurbishment tasks and the associated man-hour requirements and O&M costs become a thing of the past. The cost of a new Masterpact® breaker and the required DCP is less than the cost of most breaker overhauls. Additionally, the Masterpact® PM cycle frequency is six years; maintenance tasks can be accomplished in two to four hours with no lubrication or routine replacement parts required.

For medium voltage applications, NLI supplies Square D’s Magnum™ breaker series. Magnum™ series breakers have multiple configurations to be direct replacements for all popular legacy models. Medium voltage replacement breakers utilize either vacuum or SF6 technology.

Besides offering new replacement breakers, NLI provides repair and refurbishment service for all brands of breakers.  Low voltage breakers are retrofitted with Sure-Trip solid-state trip units as required (Micrologic® trip units are specified for new Masterpact® breakers). Work is performed in our Fort Worth, TX manufacturing facility.