Walsin Technology (Walsin) splits its 379 metal oxide varistors into four series:
Standard (D) with 170 parts, Industrial with 101, Super High Energy (V) with 60 and High
Energy (E) with 48. Select on peak surge current, not on voltage. At 130Vac working voltage
the four series span 400 A to 80,000 A across 17 part numbers.
All figures are measured from Venatech’s extract of Walsin’s own varistor parametric data,
379 rows, no duplicates.
Which Walsin MOV series should I select?
Start from the surge energy you must absorb, then read the series off the peak current
column. Walsin’s four series overlap almost completely on voltage. Standard (D) is the only
series that reaches low voltages, from 11Vac. The other three all start at 130Vac. What
separates them is disc diameter and peak current.
| Series | Parts | Disc sizes held | Peak current range | Working voltage range |
|---|---|---|---|---|
| Standard (D Series) | 170 | 5, 7, 10, 14, 20, 25 mm | 100 A to 18,000 A | 11Vac to 680Vac |
| High Energy (E Series) | 48 | 5, 7, 18 mm | 800 A to 9,000 A | 130Vac to 680Vac |
| Super High Energy (V Series) | 60 | 10, 14, 20 mm | 4,000 A to 13,000 A | 130Vac to 680Vac |
| Industrial | 101 | 32, 34 mm square, 40, 53 mm | 30,000 A to 80,000 A | 130Vac to 750Vac |
Standard (D) is the only series covering low-voltage clamping, at 11Vac to 95Vac on the 5 mm
through 20 mm discs. High Energy (E) and Super High Energy (V) do not overlap on disc size —
E is 5, 7 and 18 mm, V is 10, 14 and 20 mm. Industrial starts where Standard’s largest disc
stops, at 30,000 A against 18,000 A.
Varistor voltage runs 18Vdc to 1068.5Vdc across the 379-part set, and every part carries the
same plus or minus 10% tolerance.
What is the difference between the E series and the V series?
Disc diameter and peak current, at the same working voltage. High Energy (E) covers 5 mm,
7 mm and 18 mm discs at 800 A, 1,750 A and 9,000 A. Super High Energy (V) covers 10 mm,
14 mm and 20 mm at 4,000 A, 8,000 A and 13,000 A. Voltage coverage is identical, 130Vac to
680Vac, 20 steps each.
There is no 10 mm High Energy (E) part and no 7 mm Super High Energy (V) part, so at a given
footprint only one series exists.
Peak current per disc size:
| Disc size | Standard (D) | High Energy (E) | Super High Energy (V) | Match / mismatch |
|---|---|---|---|---|
| 5 mm | 100 A and 400 A | 800 A | not offered | Mismatch — no V part at 5 mm |
| 7 mm | 250 A and 1,200 A | 1,750 A | not offered | Mismatch — no V part at 7 mm |
| 10 mm | 500 A and 2,500 A | not offered | 4,000 A | Mismatch — no E part at 10 mm |
| 14 mm | 1,000 A and 4,500 A | not offered | 8,000 A | Mismatch — no E part at 14 mm |
| 18 mm | not offered | 9,000 A | not offered | Match — E only size in the data |
| 20 mm | 2,000 A and 6,500 A | not offered | 13,000 A | Mismatch — no E part at 20 mm |
| 25 mm | 18,000 A | not offered | not offered | Match — D only size in the data |
Note that the Standard series carries two peak current figures at every disc size except
25 mm. On a 10 mm disc, parts from 11Vac to 40Vac are rated 500 A and parts from 50Vac up
are rated 2,500 A. The low-voltage parts are not the same surge device as the high-voltage
parts in the same size.
How do I tell a High Energy part from a Super High Energy part?
You cannot do it from the suffix letter. Both series end in E. SR201K05E is a 5 mm
High Energy (E) part rated 800 A. SR201K10E is a 10 mm Super High Energy (V) part rated
4,000 A. The two-digit size code, 05 against 10, is the only thing in the part number
that separates them.
Unique to Venatech’s data. All 60 parts Walsin lists under “Super High Energy
(V Series)” carry anEsuffix in the part number, not aV. The 48 parts under
“High Energy (E Series)” also end inE. That is 108 parts sharing one suffix letter
across two series with different energy grades. The only discriminator in the part
number is the two-digit size code:05,07and18are High Energy, while10,
14and20are Super High Energy. Anyone matching on the trailing letter alone will
merge two series. This does not appear in any Walsin published material; it comes from
crosstabbing the series column against the part number suffix in Walsin’s own export.
The Industrial series has the same trap. Split on the last character and Industrial looks
like 80 D parts and 21 R parts. The 34 mm square discs come in two grades, coded 34R
and 34RD. The 21 parts ending 34RD
are rated 80,000 A; the 21 ending 34R are rated 40,000 A. A last-character split puts
the 80,000 A parts in with the plain-D 32 mm, 40 mm and 53 mm parts, which are rated
30,000 A, 40,000 A and 70,000 A. Read the whole size code, not the final letter.
How much peak surge current does each Walsin MOV series handle?
From 100 A to 80,000 A. The clearest way to see it is to hold voltage constant. Every one
of the four series carries a part at 130Vac working voltage and 205Vdc varistor voltage.
Seventeen part numbers share that rating and nothing else.
| Part number | Series | Disc size | Peak current | Match / mismatch against SR201K10D |
|---|---|---|---|---|
| SR201K05D | Standard (D) | 5 mm | 400 A | Voltage match, 6x lower peak current |
| SR201K07D | Standard (D) | 7 mm | 1,200 A | Voltage match, 2.1x lower peak current |
| SR201K10D | Standard (D) | 10 mm | 2,500 A | Reference part |
| SR201K14D | Standard (D) | 14 mm | 4,500 A | Voltage match, 1.8x higher peak current |
| SR201K20D | Standard (D) | 20 mm | 6,500 A | Voltage match, 2.6x higher peak current |
| SR201K25D | Standard (D) | 25 mm | 18,000 A | Voltage match, 7.2x higher peak current |
| SR201K05E | High Energy (E) | 5 mm | 800 A | Voltage match, smaller disc, 3.1x lower |
| SR201K07E | High Energy (E) | 7 mm | 1,750 A | Voltage match, smaller disc, 1.4x lower |
| SR201K18E | High Energy (E) | 18 mm | 9,000 A | Voltage match, 3.6x higher peak current |
| SR201K10E | Super High Energy (V) | 10 mm | 4,000 A | Size match, 1.6x higher peak current |
| SR201K14E | Super High Energy (V) | 14 mm | 8,000 A | Voltage match, 3.2x higher peak current |
| SR201K20E | Super High Energy (V) | 20 mm | 13,000 A | Voltage match, 5.2x higher peak current |
| SR201K32D | Industrial | 32 mm | 30,000 A | Voltage match, 12x higher peak current |
| SR201K34R | Industrial | 34 mm square | 40,000 A | Voltage match, 16x higher peak current |
| SR201K40D | Industrial | 40 mm | 40,000 A | Voltage match, 16x higher peak current |
| SR201K53D | Industrial | 53 mm | 70,000 A | Voltage match, 28x higher peak current |
| SR201K34RD | Industrial | 34 mm square | 80,000 A | Voltage match, 32x higher peak current |
Compare SR201K10D and SR201K10E: same disc diameter, working voltage, varistor voltage
and tolerance, one letter apart. The E part is rated 4,000 A against 2,500 A, a 60%
increase for an identical footprint. If a 10 mm Standard part is marginal on surge, the
Super High Energy part in the same size is the first thing to try.
Note also that SR201K34R and SR201K40D both carry 40,000 A on different geometries — a
34 mm square disc and a 40 mm round disc. Peak current alone does not tell you which fits
the mechanical envelope.
What does the Industrial series add over a 25 mm Standard part?
A step change in surge capability and a wider top-end voltage. The largest Standard part,
the 25 mm disc, is rated 18,000 A. The smallest Industrial part, the 32 mm disc, is rated
30,000 A. Industrial also reaches 750Vac working voltage against 680Vac for the other three
series.
Industrial is 101 parts across four geometries: 32 mm round (19 parts, 30,000 A), 34 mm
square in two grades (21 parts at 40,000 A and 21 at 80,000 A), 40 mm round (19 parts,
40,000 A) and 53 mm round (21 parts, 70,000 A). Working voltage runs 130Vac to 750Vac, and
varistor voltage reaches 1181Vdc, the highest figure in the whole 379-part set. Treat these
as chassis or busbar components and confirm mounting against the drawing.
How do I read a Walsin MOV part number?
Five fields. Take SR431K10E: SR is the varistor prefix, 431 is the varistor voltage
code, K is the plus or minus 10% tolerance letter, 10 is the disc diameter in
millimetres, and E is the energy grade. The varistor voltage code reads as two
significant digits and a multiplier, so 431 is 43 x 10, or 430Vdc.
The same convention holds across all four series. SR180K05D is
18Vdc on a 5 mm Standard disc. SR751K34R is 750Vdc on a 34 mm square Industrial disc.
SR112K10D is the one to watch: the code rounds to 110 x 10 while the published varistor
voltage is 1068.5Vdc, so the code is a nominal marker, not the exact figure. Sort on the
varistor voltage column rather than on the part number.
Is a bigger disc always the right answer?
No. A larger disc raises peak current capability but it also raises capacitance and
physical footprint, and it does not change the clamping voltage. Two parts at the same
varistor voltage clamp at the same nominal level regardless of diameter. Oversizing buys
surge energy, not a tighter clamp.
Select in order: working voltage, which sets the varistor voltage; then surge energy, which
sets disc size and series; then whether that combination exists.
Does the varistor data tell me packing, SPQ or MOQ?
No. The Packing, SPQ and MOQ columns are present in Walsin’s varistor export and
empty on all 379 rows. The export gives part number, series, size, maximum working
voltage, varistor voltage, tolerance and peak current, and nothing about how the part
ships.
Unique to Venatech’s data. Walsin’s varistor parametric export carries
Packing,
SPQandMOQas named columns and fills none of them, on any of the 379 rows. A buyer
pulling this file expecting reel or bag information, standard pack quantity or minimum
order quantity gets three empty columns. Venatech resolves those against the current
packing specification on request.
Ask for the position on the specific part number rather than reading a quantity off any
published table.
FAQ
How many MOV varistors does Walsin list?
Walsin Technology (Walsin) lists 379 metal oxide varistors in four series: Standard (D Series) with 170 parts, Industrial with 101, Super High Energy (V Series) with 60 and High Energy (E Series) with 48. Walsin’s own product counter says 380, because it counts the header row of the export.
What is the difference between Walsin’s E series and V series varistors?
Disc diameter and peak current, at identical voltage coverage. High Energy (E) covers 5 mm, 7 mm and 18 mm discs at 800 A, 1,750 A and 9,000 A. Super High Energy (V) covers 10 mm, 14 mm and 20 mm at 4,000 A, 8,000 A and 13,000 A. Neither series shares a disc size with the other.
Why do Walsin’s V series varistors end in E?
Walsin’s export assigns an E suffix to every one of the 60 Super High Energy (V Series) parts as well as to all 48 High Energy (E Series) parts. Only the two-digit size code separates them: 05, 07 and 18 are High Energy, 10, 14 and 20 are Super High Energy. Match on the size code, not the suffix.
Which Walsin varistor has the highest peak current?
The 21 Industrial parts coded 34RD are rated 80,000 A, the highest figure in the 379-part extract. SR201K34RD is one of them, at 130Vac working voltage and 205Vdc varistor voltage on a 34 mm square disc. The 53 mm round Industrial parts follow at 70,000 A.
Can I use a 10 mm varistor where a 14 mm part is specified?
Only if the peak current still covers the surge. A 10 mm Standard part is rated 2,500 A against 4,500 A for the 14 mm Standard part at the same voltage. The Super High Energy part at 10 mm gives 4,000 A, which closes most of the gap but does not match it.
What tolerance do Walsin varistors come in?
One. All 379 parts in the extract carry a plus or minus 10% tolerance on varistor voltage. There is no tolerance selection to make and no tighter grade listed. The tolerance letter K appears in every part number in the set.
Does Walsin publish a joule rating for its varistors?
Not in the parametric export. The export gives peak current in amps, working voltage, varistor voltage and tolerance. Energy in joules, clamping voltage, leakage current and capacitance are not columns in the file. Those figures have to come from the series datasheet drawing tables.
Are UL or VDE approvals listed in Walsin’s varistor data?
No. No safety-agency approval appears anywhere in the 379-row export — not UL, not VDE, not ENEC, not CQC. Any approval claim for a Walsin varistor must be confirmed against the current certificate or the series datasheet before it goes into a compliance file.
Next step
Selecting a varistor is a two-column problem: fix the working voltage, then fix the peak
current. Send the surge requirement and the footprint you have and Venatech Limited, an
authorised Walsin distributor in Hong Kong, will return the series, the disc size, the
peak current figure and whether the combination exists in Walsin’s range at all.
Send your BOM to Venatech · Browse the
Walsin varistor range · Read
How to choose an MOV varistor and
Walsin passive components in Hong Kong stock.
Cross it yourself. The cross-reference tool takes a single part number or a whole BOM column and returns the Walsin candidates with every field that differs stated plainly — qualification stays with you. Ready stock shows what is held in Hong Kong today, with an RFQ against any line.