Safety Capacitor Certificate Number: Zero of Walsin’s 929 Disc Rows Name One

We searched every cell of Walsin’s 929-row disc capacitor export for a safety capacitor certificate number. Zero rows contain one. 367 rows do state a safety class — X1, Y1 or Y2 — but only inside the series name and a rating column, never in a dedicated field, and never alongside a standard or a certificate.

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Venatech Limited, an authorised Walsin distributor in Hong Kong, holds Walsin Technology (Walsin)’s disc capacitor export, Walsin_DiscCap_ALL.xlsx, 929 rows and 11 columns, and the chip safety export, 15_Safety_X1Y2_S2.xlsx, 173 rows. Every part number below is real, and every count is a count of part numbers, not pieces.

How many of Walsin’s 929 disc capacitor rows name a safety class, a standard, or a certificate?

367 name a class. Zero name a standard. Zero name a certificate. We searched all 929 rows, cell by cell, for the words TUV, CQC, UL, IEC, for the standard number 60384, and for all five certificate numbers Venatech holds — TUV R50381780 and R50195920, UL file E182369, CQC20001280137 and CQC20001280136. Every one of those searches returned zero rows. A prior measurement found none of the five certificates has a matching row in any export file, and this disc file reproduces that finding exactly.

What we searched for	Rows matched, of 929	Where it lives
A safety class (X1, Y1 or Y2)	367	Series column and UR column, both free text
A test standard (60384 in any form)	0	Nowhere
Any of the five certificate numbers	0	Nowhere
The words TUV, CQC or UL	0	Nowhere
No safety class at all	562	—

The safety class is real and it is on 39.5% of the file. The standard and the certificate are real too, and they are on 0% of it.

Which column actually carries the safety class, and how reliable is it?

Two columns, and they agree with each other on every single row. We checked the Series column and the UR column independently: 367 rows have “Safety” in Series, and the identical 367 rows have a Y1, Y2 or X1 token in UR. Zero rows disagree between the two. That sounds reassuring until you notice neither column was built to carry the class — Series is a marketing-style product name and UR is a rated-voltage field that happens to spell the class out because the voltage and the class are issued together.

Part number	Series says safety?	UR string	Match / mismatch vs a dedicated “Safety class” column
YP0AC101K060	Yes	X1-440Vac/Y2-250Vac	Mismatch — class is embedded in a voltage string, not a class field
SL602101J090	No	6000Vdc	Match on absence — no class anywhere, correctly
YP0AH101K060	Yes	X1-400Vac/Y1-250Vac	Mismatch — same problem, different class
ZV500203Z070	No	50Vdc	Match on absence
YP0AS101K070	Yes	X1-760Vac/Y1-500Vac	Mismatch — highest X1 rating in the file, still no class field

Two free-text columns agreeing perfectly is not the same as one structured field. A filter built on either column is reading a product name or a voltage string and inferring a class from it — correctly, so far, but by inference rather than by a flag Walsin declared as a class.

Does the digit inside the part number predict the exact rating, with no column at all?

Yes, on all 367 rows, and we have not seen this decode published anywhere. We split each safety part number into its two-letter dielectric prefix, the digit that follows it, and the two-letter family code — AH, AC or AS. Grouping by just the digit and the family code gives 8 distinct combinations, and every one maps to exactly one UR string, with zero exceptions across all 367 rows.

Digit + family	UR string it always means
0 + AH	X1-400Vac/Y1-250Vac
1 + AH	X1-400Vac/Y1-400Vac
5 + AH	X1-500Vac/Y1-500Vac 1500Vdc
0 + AC	X1-440Vac/Y2-250Vac
1 + AC	X1-440Vac/Y2-300Vac
5 + AC	X1-500Vac/Y2-500Vac 1500Vdc
7 + AC	X1-440Vac/Y2-300Vac 1500Vdc
0 + AS	X1-760Vac/Y1-500Vac

So the rating is not missing information — it is redundant information, printed once in the part number and once in UR, and never in a column you could filter on by name. YP0AC101K060 and YP1AC101K060 differ by exactly that one digit and nothing else in the part number, and it is the only thing telling you 250 Vac from 300 Vac on the Y side.

Does the same gap exist on the chip S2 safety export?

Yes, identically. We ran the same cell-by-cell search against 15_Safety_X1Y2_S2.xlsx, 173 rows and 16 columns. Zero rows contain any of the five certificate numbers, the words TUV, CQC or UL, or the standard number 60384 — the same zero we found on the disc file. The difference is what backs it up: we hold a 14-page approval sheet for the chip S2 series, 16_Safety_X1Y2_General_S2.pdf, and its General Electrical Data page prints TUV R50381780, UL file E182369 and CQC20001280137 next to the series name. For the disc file we hold no datasheet at all, so the same zero-in-the-export result means something worse on the disc side: there is no document anywhere in our library that ties a certificate number to an AH, AC or AS part number.

Why can a cross-reference tool filter for safety certified but never show a certificate number?

Because the filter and the certificate are two different things, and only one of them is a column. A “safety certified” filter works by matching the Series text, exactly the way we just showed it can be read — reliably, but by inference. The certificate number is never a column in any of the 929 disc rows or the 173 chip rows, so no selector, ours included, can display one automatically. We send the approval sheet that carries the number on request, and for the disc line we say plainly that no such sheet exists in what we hold.

What happens to the 562 non-safety rows that write a Y5-style dielectric code?

They are not Y-class parts, and the class-free rows in this file are the majority, not the exception. 562 of 929 disc rows — Class I Temperature Compensation, Class II HI-K, and the two Low Dissipation series — carry no safety class token anywhere, in Series or in UR. Some of them do carry a dielectric code that starts with the letter Y, such as Y5R on 47 Low Dissipation rows, which is an EIA temperature-characteristic code, not a mains safety class. Reading “Y” in the dielectric column as a safety signal would be a mistake on every one of those 47 rows; the only reliable signal is the Series and UR pair we measured above, and neither of those is the dielectric field.

What should a buyer verifying a safety capacitor certificate number actually do?

Ask for the document, not the column. Of the 1,125 part numbers on the Venatech ready stock snapshot as at 23 September 2026, three sit in the safety capacitor line and all three are chip S2 parts with a certificate behind them on paper. None of the 367 disc safety rows is on that snapshot, and none has a certificate-bearing document in our library at all.

1. Check us first. UL file E182369 is searchable in UL’s own public database in about thirty seconds. Ask for the approval sheet that names it for your exact series.
2. Cross the whole BOM in one pass. Paste up to 500 part numbers or drop your Excel or CSV into the free cross-reference tool, and use the safety-certified filter — it matches Walsin’s published catalogue by series name, which is the honest description of what it does.
3. Check what is physically in Hong Kong on ready stock before you commit to a slot — a dated snapshot as at 23 September 2026, not a live feed.

For the field-by-field comparison between the two safety shelves, see Y capacitor safety selection: disc covers 400-760 Vac, chip S2 stops at 310. For the dual rating system inside the UR column itself, see the disc capacitor UR column holds two incompatible rating systems. The range sits on the Walsin disc capacitor page.

The short version

A safety capacitor certificate number does not live in Walsin’s disc capacitor export, or in its chip S2 export, or in any of the 929 plus 173 rows we searched cell by cell. The safety class does live there, on 367 of 929 disc rows, carried redundantly by the Series name and the UR string, and — we found this ourselves — by a single digit inside the part number that predicts the exact rating across all 367 rows with zero exceptions. The certificate itself exists only in a document: a 14-page sheet for chip S2, and nothing at all for the disc line. Qualification stays with you.

Send us the safety capacitor off your BOM and we will tell you plainly whether a certificate-bearing document exists for it — and if it is a disc part, we will tell you that one does not, rather than let a filter imply otherwise.

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Frequently asked questions

<!– wp:rank-math/faq-block {"questions":[{"id":"faq-question-01","title":"Does Walsin's disc capacitor export contain a certificate number?","content":"No. We searched all 929 rows, cell by cell, for TUV, CQC, UL, the standard number 60384, and all five certificate numbers Venatech holds. Every search returned zero rows. The export has no column for a certificate, a standard or a safety class at all.","visible":true},{"id":"faq-question-02","title":"How many Walsin disc capacitors state a safety class, and where?","content":"367 of 929. The class appears in the Series column as free text — for example \”Safety Certificated Caps X1/Y1_(AH series)\” — and again in the UR rated-voltage column, such as X1-400Vac/Y1-250Vac. The two columns agree on all 367 rows with zero disagreement, but neither is a dedicated class field.”,”visible”:true},{“id”:”faq-question-03″,”title”:”Can the exact safety rating be read from the part number alone?”,”content”:”Yes, on the disc safety parts. The digit immediately after the two-letter dielectric prefix, combined with the AH, AC or AS family code, predicts the exact UR string on all 367 rows with zero exceptions — eight combinations, eight distinct outcomes. This is a measurement from the export, not a published Walsin rule, so it is flagged for confirmation.”,”visible”:true},{“id”:”faq-question-04″,”title”:”Does the chip S2 safety capacitor export name its own certificates?”,”content”:”No, the export does not — the same cell-by-cell search returns zero on all 173 rows. The difference is that Venatech holds a 14-page approval sheet for the S2 series that prints TUV R50381780, UL file E182369 and CQC20001280137 on its electrical data page. No such document exists for the disc line.”,”visible”:true},{“id”:”faq-question-05″,”title”:”Why does a dielectric code starting with Y not mean Y-class safety?”,”content”:”Because disc capacitors use two unrelated systems that both start with the letter Y. Y5R, Y5P, Y5U and Y5V are EIA temperature-characteristic codes for Class II ceramic dielectric, written in the Dielectric column. The mains safety Y1 and Y2 classes are a different system entirely, written in Series and UR. 47 rows carry the Y5R dielectric code and none of them is a safety-certified part.”,”visible”:true},{“id”:”faq-question-06″,”title”:”Can a cross-reference tool show a safety capacitor’s certificate number automatically?”,”content”:”No selector can, because the certificate number is not a column in any export Venatech holds, 929 disc rows or 173 chip rows. A safety-certified filter works by matching the series name, which is reliable for identifying the class but cannot display a certificate that was never in the data.”,”visible”:true},{“id”:”faq-question-07″,”title”:”What is actually in Hong Kong stock for certified safety capacitors?”,”content”:”Three chip S2 part numbers, as at the 23 September 2026 snapshot, each backed by the S2 approval sheet. None of the 367 disc safety rows is on that snapshot, and none has a certificate-bearing document behind it in anything Venatech holds.”,”visible”:true}],”listStyle”:””,”titleWrapper”:”h3″,”titleCssClasses”:””,”contentCssClasses”:””,”sizeSlug”:””} –>

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