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
LeCroy LC534A
SSI High Current Surge Generator
Velonex 587E/V-2734
Tektronix P5100
Tektronix P6015A
Pearson 1423
Pearson 110A
Digital Oscilloscope
Digital Oscilloscope
Surge Generator
Surge Generator
100:1 Probes
1000:1 Probes
1000:1 Current Transformer
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.
First stage let-through voltage (765 Vpk)
Total current and second stage current overlaid. (Second stage current is
960 A)
Note the reduction in surge current from the first stage.
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.
Third stage let-through voltage (354 Vpk)
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.
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 ring wave third 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.