Surge Test Report Testing was performed at the Surge Suppression Incorporated test lab to determine the effects of cascade protection on let-through voltage performance of various surge protective devices. Tests Performed:

1) The input surge was an IEEE Std. C62.41.2-2002, Cat. C High 10 kA 8x20 µs pulse (6500 Vpk static test). The test was performed using three surge protectors with 5 meters of 12 AWG wire between them to simulate an installation. Surge current and let-through voltage measurements were taken at each stage.

2) The input surges were IEEE Std. C62.41.2-2002 30 ohm ring wave

pulses at 90 degrees. A 2 kV surge at 270 degrees and a 6 kV surge at 90 degrees was applied. The test was performed using three surge protectors with 5 meters of 12 AWG wire between them to simulate an installation. Let-through voltage measurements were taken at each stage.

Test Equipment Used: LeCroy Wavesurfer 42XS Digital Oscilloscope LeCroy LC534A Digital Oscilloscope SSI High Current Surge Generator Surge Generator Velonex 587E/V-2734 Surge Generator Tektronix P5100 100:1 Probes Tektronix P6015A 1000:1 Probes Pearson 1423 1000:1 Current Transformer Pearson 110A 10:1 Current Transformer

Tested Units: LSEA3Y1 CDLA3Y1 S-SPT120-30 Test Date: 3/27/08 Tests Performed by:

Ricky J. Fussell, BSET

Simplified Schematic:

Surge In Stage 1 LSEA3Y1

Stage 2 CDLA3Y1

Stage 3 S-SPT120-30

5 meters (16.4 ft) 12 AWG Stranded wire

Note: Stage 1 and 2 were connected using 15 cm (6 inch) leads. Stage 3 is a series connected device.

Test Setup Photos:

Generator and test units

Detail of first stage and current transformers.

Stage 2 detail Stage 3 detail

Oscilloscope and probes detail

Results: Test 1 (10 kA 8x20 µs input)

Total current and first stage current overlaid. (Total current 10.02 kA)

Total current and first stage current overlaid. (First stage current 9.18 kA) Notice that most of the surge current is diverted in this stage.

Total current and second stage current overlaid. (Second stage current is 960 A) Note the reduction in surge current from the first stage.

First stage let-through voltage (765 Vpk)

Second stage let-through voltage (351 Vpk) Note a 414 Vpk reduction from the first stage.

Total current and stage 3 current overlaid. (Stage 3 current is 320 A) Note the reduction in surge current from the second stage.

10 kA 8x20 µs Surge Comments:

The reduction in surge current from stage to stage in this cascade approach is dramatic. It reduces from 9,180 amps to 320 amps in these three stages. This reduction alone lowers the surge energy to safe levels for sensitive equipment. The let-through voltage reduction is most dramatic up to the second stage and then continues at about the same level in the third stage. This is due to the fact that the SPD reacts to high energy surges with clamping components that must also allow the power frequency voltage to pass. The actual surge voltage was 6,500 Vpk so the total reduction was 6,500-354=6,146 Vpk.

Third stage let-through voltage (354 Vpk)

Test 2 (6 kV/30 ohm ring wave and 2 kV/30 ohm ring wave input)

6 kV/30 Ohm Ring Wave at 90 Degrees

6kV ring wave first stage let-through voltage (490 Vpk measured from zero or 320 V from sine wave peak)

6 kV ring wave second stage let-through voltage (207 Vpk measured from zero or 37 V from sine wave peak)

6 kV ring wave third stage let-through voltage (207 Vpk measured from zero or 37 V from sine wave peak)

2 kV/30 Ohm Ring Wave at 270 Degrees

2 kV ring wave first stage let-through voltage (458 Vpk measured from the 270 degree insertion point.)

2 kV ring wave second stage let-through voltage (25 Vpk measured from the 270 degree insertion point.)

2 kV and 6 kV 30 Ohm Ring Wave Comments: The first stage is a standard clamping device so it reacts to the ring waves by clamping as it would with a combination wave. The second and third stages are sine wave tracking devices that greatly attenuate the ring waves. In both cases (2 kV and 6 kV) the surge is reduced to insignificant levels. Notice there is some upstream effect of sine wave tracking to the previous stage. This allows the first stage to get some of the benefit of the downstream sine wave tracking devices.

2 kV ring wave third stage let-through voltage (25 Vpk measured from the 270 degree insertion point.)