Delta LA303 AC Lightning Arrestor, Three Phase (3 or 4-Wire)

Delta LA303 AC Lightning Arrestor, Three Phase (3 or 4-Wire)
Delta LA303 AC Lightning Arrestor, Three Phase (3 or 4-Wire)
For 250 Volt 3 Phase 3 or 4 Wire Service.

Currently In Stock: 10

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Item code Brand name Model number
DELLA-3PHASE Delta Lightning Arrestors LA303

Untitled Document
altE Delta Lightning Arrestor LA303

AC Lightning Arrestor
3 or 4 Wire, Three Phase
LA 303

Rapid response, high current Delta Lightning Arrestors help prevent damage to computers and other electronic equipment. The Delta LA Series handles the big surges, like lightning up to 50,000 amps, passing them harmlessly to the ground.

While it is not possible to achieve 100% protection, Delta units will greatly reduce problems due to lightning, power surges and voltage spikes. The LA303 model for 110/208/250VAC, three phase systems (5 wire service) can be used for applications where three hot wires of a three phase system are to be protected.


  • employ a non-conductive base to prevent a blown arrestor from creating a shock hazard
  • do not cover adjacent equipment with carbon dust on failing, preventing damage to other equipment
  • always fail "clear" to permit continued use of the power system
  • are based on a silicon material to provide quicker operation at lower conduction resistance
  • will pass a large number of high-energy surges and half-cycle spikes prior to failing
  • feature extra long leads to ease installation
  • have locknut and bushing furnished
  • are available in a variety of voltages or number of poles

LA 303 Specifications

Rated Voltage Design Type Surge Current Max. Energy Leads Enclosure Rating Dimensions
Three Phase
3 or 4-Wire Service
Silicon Oxide Varistor™ 100,000 amps 3,000 Joules
per pole
36" #12 THHN NEMA 4 4.5" Height, 2.25" Diameter

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