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AC Industrial Surge Arrester
300Vac, 3 Phase, 4-wire

Silicon Oxide Varistor type arrester.  This is a very economical way to provide a degree of lightning and surge protection for a whole electrical system.   Designed to fit any load center using a 1/2 inch knockout for mounting.  Arrestor is Installation is completed by connecting the single white wire to the panel's neutral bar and the other two wires to the 240V supply in the panel.  This one device will protect your entire downstream electrical system although surge protectors are still recommended at sensitive appliances, electronic equipment and computers.  Designed for use on three-phase, four-wire 120/208 Vac or 240 Vac electrical services.  Uses Silicon Oxide Varistor design to arrest voltage surges with a low resistance path line-to-line, line-to-neutral, or line-to-ground while providing a high resistance path to the 50/60 Hz power source.  This arrester responds faster and has a lower clamping voltage than comparable gapped arresters.  Response time is 25 nanoseconds to clamp 50,000 amps.  Maximum current rating of 100,000 amps and 3,000 joules per line.  Waterproof and can be used on outdoor panels.  Made in USA  


Lightning is a major source of voltage spikes that can damage or destroy your investment.  Don't risk the damage and outage time by not installing arresters!

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Note that all arresters can fail when hit with a high surge due to a nearby lightning strike.  This arrester is designed to limit consequences of such a failure. 


* Locknut and bushing furnished for simple mounting.
* Extra long 36" #12 THHN leads for ease of installation.
* Will pass a large number of high-energy surges and half-cycle spikes prior to failing.
* Always fails "clear" to permit continued use of power system.
* Non-conductive base to prevent a blown arrester from being a shock hazard.
* Will not produce carbon dust upon failing like some other arresters, preventing
   damage to other equipment
* 4-1/4" high, 2-1/4" diameter
* PVC weatherproof case
* Locknut and washer furnished
* 1" bottom plug relieves internal pressure for any surges well above rating
* UL and cUL Recognized

Simple to install on outside of load center panel, or inside.

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- for wire lengths more than 4" twist together one turn every 4"

Conduction Characteristics

8 x 20 microsecond wave shape per IEEE 28 ANSI & NEMA C62.1
5 nanosecond response time at 1 milliamp
10 nanosecond response time at 10,000 amps
25 nanosecond response time at 50,000 amps
3000 Joules per pole
Discharge Current Clamping Voltage
Number of Operations
5,000 amps 240 V unlimited
10,000 amps 480 V unlimited
20,000 amps 840 V unlimited
40,000 amps 1300 V unlimited
60,000 amps 2000 V unlimited
80,000 amps 3000 V one time
100,000 amps 4000 V one time


Customers who purchased this product also ordered:
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Surge Capacitor CA-603-R.


Item Number: LA-303
Price: $64
Price last updated 2/10/2018
Shipping Weight: 4 lbs.
This item normally ships in approximately 3 days or less.


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