Secondary level protection of sub-panels, isolated circuits and control panels.


Up to 120 KW systems in Category B locations.

The StediWatt GAR’DIAN Series is intended for industrial, commercial secondary-level protection. It provides a safe, critical surge path direct to ground, effectively isolating individual circuits and equipment from utility line hazards and internal electrical pollution. Not intended for use as primary level protection, these models are designed for applications downline from StediWatt’s Hi-Energy, Non-Degrading primary level TVSS models. Ideal for hazard-prone areas where critical, system-dependent equipment or expensive downtime risk is a factor. Don’t let internal surging deteriorate your investments, order your GAR’DIAN system protection today!

  • For 120VAC, Single Ø - up to 480VAC 3Ø applications
  • MCOV Ratings: 130/320; 320/550 VAC Max. (typ.)
  • Multi-Element Surge Capacity Per Mode: 40,000 Amps
  • Minimum Surge Current Per Phase: 80,000 Amps
  • Rated Total Surge Capacity (New): 240,000 Amps*
  • All Modes of Protection: L-L, L-N, L-G and N-G (if applies)
  • Leads are #12 Copper, Max 36" for fastest response time
  • Minimum degradation if downline from Primary TVSS Series
  • User Safe, StediWatt Safety Surge Cushion™ *Patent Pending
  • UL and CUL Listed to Standard 1449, 2nd Edition
  • Easy panel mounting options. Includes 1/2" offset nipple
  • Safety tested to ANSI/IEEE C62.11,C62.41 & C62.45 Std. 587
  • FuseLink Technology Maintains Full Rated Surge Capacity
  • LED Self-test Protection Status Monitors for each phase
  • Features Alum. Alloy NEMA Type 12 Rated Enclosures
  • Manufacturer's 10 Year Full Replacement Warranty
  • Lifetime Manufacturer’s Replacement Module Guarantee
* Some Specifications will vary depending on the voltage configuration. Refer to spec sheet for full information.
Features Multi-Element TVSS Protection That Blankets Your Downline Circuits and Equipment!
240,000 Amps of Safe, “Multi-element" Surge Capacity for Secondary Level Protection!
Protects integrity of, and isolates all branch circuits, control panels, and control modules!
Easy Mounting and Installation for efficient ‘Close-Coupled’ equipment-level protection!
Safely protects sensitive electrical equipment and total system load capacities up to 100KW!
Increases the safety, efficiency and performance of your overall electrical power system!


Model S-1120-3G S-1208-4G S-1240-3G S-1240-4G S-1480-3G S-1480-4G
AC Service Types 3Ø WYE 3Ø Delta 3Ø Hi-Leg 3Ø Delta 3Ø WYE
Nominal AC Line Voltage (VRMS) 120/240 120/208 240/240 120/208/240 480/480 277/480
Frequency Range - USA / Euro Std 50/60 Hz 50/60 Hz 50/60 Hz 50/60 Hz 50/60 Hz 50/60 Hz
Multi -Element ME* Protection Modes L-N; L-L L-N; L-L & N-G L-L L-N; L-L & N-G L-L L-N; L-L & N-G
Knock Out Size for Mounting 1/2" 1/2" 1/2" 1/2" 1/2" 1/2"
Leads: #14 AWG Stranded Copper 3+G 4+G 3+G 4+G, Hi-Leg 3+G 4+G
Max. ME* Per Mode Surge KVA 40 40 40 40 40 40
Max. Surge Current Per Phase KVA 80 80 80 80 80 80
Total Surge Capacity (KVA@ 8x20 μsec pulse) 120 240 150 240 150 240
Max. Continuous Operating Voltage (MCOV) 140/320 140/320 320 140/320/320 550 320/550
Max. Clamping Voltage - L-L 520 520 520 520 1175 1175
Max. Clamping Voltage - L-N 390 390 N/A 390 N/A 675
Max. Clamping Voltage - N-G 390 390 N/A 390 N/A 390
Warranty 15 Years per Manufacturers Warranty Guidelines
Enclosure Dimensions (HxWxD) 4 1/2" X 4 1/2" X 2 3/4"
Enclosure Type NEMA/EEMAC Type 12 Waterproof, Explosion Proof, Spark Proof with Embeded PCB and Contacts
Certifications UL / CUL Std 1449, 3rd Editi on and Full Line is ETL Certi fi ed, Safety Tested and Listed
Safety Testing UL & ANSI/IEEE C62.11,C62.41 & C62.45 Std. 587 and NEMA Std. LS-1
Protection Status Indicators Lifetime Green LED Self Test Indicators For Each Phase
Shipping Weight Lbs (Approx.) 3.2 3.85 3.5 3.85 3.8 4.25