Mining electronics for Australia put surge protection on high-voltage supplies, and the Walsin Technology (Walsin) varistor export shows how thin that top end is. We counted it: 34 of 101 Industrial-series rows reach 460 volts AC or more, exactly 1 of 379 rows goes above 680 volts AC, and none is on our Hong Kong shelf as at 23 September 2026.
Venatech Limited, an authorised Walsin distributor in Hong Kong, holds the Walsin varistor export of 379 rows and a stock list dated 23 September 2026. This post is for a design or procurement engineer at an Australian maker of mining drives, power equipment or control gear who has a surge-protection varistor on a bill of materials and an incumbent part number to cross. Every part number is real, every count is ours, and each news item names its source and the day we fetched it, 23 October 2026.
What do Australian mining export forecasts mean for equipment makers?
Large numbers, falling in places. A secondary summary of the September 2026 Resources and Energy Quarterly says Australian resources and energy export earnings were 403 billion Australian dollars in 2025-26 and are forecast at 422 billion in 2026-27, with iron ore at 123 billion falling to 107 billion and gold at almost 72 billion falling to 68 billion.
The detail, from the source we fetched. An article on the ima-api.org site dated 5 October 2026 reproduces the headline figures of the quarterly and adds forecasts for 2027-28 and 2030-31, including copper at 14 billion in 2025-26 and critical minerals at about 17 billion rising to 26 billion in 2026-27. We tried the government’s own publication page and its site disallows automated access, so we could not read the primary release and we report that. We draw one conclusion, and it is ours: export earnings are an operator’s revenue, not an equipment maker’s order book, so none of these numbers tells you a varistor will be bought. We have no relationship with any mining company.
How tall is the Walsin varistor ladder at the top?
Short. Across all 379 Walsin varistor rows the maximum working voltage steps from 11 volts AC to 750 volts AC, and above 680 volts AC there is exactly one row: SR122K53D, Industrial series, 53 millimetre, 750 volts AC and 70,000 amperes peak current.
We parsed the varistor export, Walsin_MOV_ALL.xlsx, one row at a time. The Industrial series has 101 rows in five body sizes: 19 at 32 millimetre and 30,000 amperes, 21 at 34 millimetre square and 40,000 amperes, 21 at 34 millimetre square and 80,000 amperes, 19 at 40 millimetre and 40,000 amperes, and 21 at 53 millimetre and 70,000 amperes. Of those 101 rows, 34 are rated 460 volts AC or more, across 8 working-voltage steps: 460, 485, 510, 550, 575, 625, 680 and 750. We have not seen this counted anywhere. The export gives the working voltage as AC only, so a DC bus needs the Walsin datasheet, which we do not hold for varistors.
Which Walsin parts cross a 460 volt AC, 34 millimetre square, 40 kiloampere brief?
One part matches, and it is not on the shelf. Take a varistor with 460 volts AC maximum working voltage, 34 millimetre square body and 40,000 amperes peak current: SR751K34R matches on all four fields, and five neighbours differ in size, surge rating or working voltage.
| Walsin part | Body, working voltage, varistor voltage, peak current | On shelf 23 Sep 2026 | Match / mismatch with the brief | Your incumbent |
|---|---|---|---|---|
SR751K34R |
34 mm square, 460 Vac, 750 Vdc, 40,000 A | No | Match on body, working voltage and peak current | |
SR751K34RD |
34 mm square, 460 Vac, 750 Vdc, 80,000 A | No | Mismatch: peak current doubled; same body and voltage | |
SR751K32D |
32 mm, 460 Vac, 750 Vdc, 30,000 A | No | Mismatch: smaller body, lower peak current | |
SR751K40D |
40 mm, 460 Vac, 750 Vdc, 40,000 A | No | Mismatch: different body; voltage and peak current match | |
SR751K53D |
53 mm, 460 Vac, 750 Vdc, 70,000 A | No | Mismatch: much larger body, higher peak current | |
SR112K34R |
34 mm square, 680 Vac, 1068.5 Vdc, 40,000 A | No | Mismatch: 680 volts AC working voltage |
In the export the R and RD suffixes mark the 40,000 and 80,000 ampere versions of the 34 millimetre square body, so the 80,000 ampere twin is the only way to double the listed rating at the same body and voltage; see our post on MOV energy ratings at 40,000 and 80,000 amperes. Confirm against both datasheets and qualify in your own circuit. Our post on how to choose an MOV varistor sets out the selection steps, and the varistor range lists the series.
What does a Hong Kong shelf hold in varistors for an Australian mining customer?
Nothing. As at 23 September 2026, 0 of the 379 Walsin varistor part numbers are on our stock list, so every varistor line, including the 34 high-voltage Industrial rows, is a quote.
That is a straight answer for a procurement engineer: for varistors the ready stock list shows nothing today, and the route is to paste your incumbent into the cross-reference tool and request a quote through the site. Stock moves; the list is a dated snapshot, never live-synced. We hold lot and date-code traceability, a certificate of conformity per shipment on request and original sealed Walsin packaging.
What will we not tell you about mining equipment?
Anything about suitability. We make no claim that any Walsin part is suitable for mining equipment or hazardous areas, none of the 28 datasheets we hold names mining, underground use or a mine site, and for varistors we hold no datasheet at all.
Every specification in this post comes from the Walsin export, not a datasheet, so treat each as unconfirmed until Walsin’s sheet is in your hands; it is on our request list. We hold no office, entity or stock in Australia. Our locations are Hong Kong, Shenzhen, Singapore and Jiangmen, with Chengdu in preparation. We give no legal, customs or conformity advice; confirm with your compliance team. Qualification stays with you.
How Venatech helps
Paste your incumbent into the free cross-reference tool, which decodes 18 manufacturers’ part numbers across 800,000+ crossable parts, and read the Walsin candidates with each field marked match or mismatch. Load a whole BOM, up to 500 part numbers or an Excel or CSV file, to run every line. The ready-stock list is a Hong Kong snapshot dated 23 September 2026, never live. Worked example from our own export: the Industrial series of 101 rows narrows to 34 at 460 volts AC or more, and the single row above 680 volts AC is SR122K53D; none of the 379 varistor lines is on the shelf, so each is quoted. Walsin is the only line we are authorised for; Stackpole and Viking are lines we supply. We serve from Hong Kong in small lots, we help with cross-referencing by hand when the tool returns no clean candidate, and a quote is requested through the site. The 28 datasheets, 451 pages, we hold are sent on request.
The short version
For an Australian mining equipment maker, the high-voltage varistor choice is narrow: 34 of 101 Industrial rows reach 460 volts AC or more, 1 of 379 rows exceeds 680 volts AC, and 0 are on the shelf. The cross is quick and the datasheet is the gap you have to close.
Send us one surge-protection line from your BOM and we will return the Walsin candidates with the differences stated and the stock position named. If your highest working voltage sits on the last step of a ladder, what is your plan when that step has one part?
Sources
Fetched 23 October 2026.
- ima-api.org article, “Resources earnings forecast to rise as global uncertainty persists”, 5 October 2026, summarising the September 2026 Resources and Energy Quarterly: https://ima-api.org/resources-earnings-forecast-to-rise-as-global-uncertainty-persists/
- Blocked: the primary release at https://www.industry.gov.au/REQSeptember2026 disallows automated access, so we did not read it.
Frequently asked questions
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What are Australia’s forecast resources and energy export earnings?
A 5 October 2026 article summarising the September 2026 Resources and Energy Quarterly reports 403 billion Australian dollars in 2025-26 and a forecast of 422 billion in 2026-27. These are the source’s figures, not ours, and we could not read the primary release.
How many Walsin Industrial varistor rows reach 460 volts AC?
34 of the 101 Industrial-series rows in the export, across 8 working-voltage steps from 460 to 750 volts AC. We counted them ourselves from the 379-row varistor export. Confirm against the Walsin datasheet, which we do not hold.
Is there a Walsin varistor above 680 volts AC?
Exactly one in the export: SR122K53D, Industrial series, 53 millimetre, 750 volts AC working voltage and 70,000 amperes peak current. It is not on our shelf as at 23 September 2026. Request a quote through the site.
Which Walsin part crosses a 460 V AC, 34 mm square, 40 kA brief?
SR751K34R matches on body, working voltage and peak current. SR751K34RD has an 80,000 ampere rating and mismatches on peak current. Neither is on our shelf. Confirm against both datasheets and qualify in your own circuit.
Do you stock varistors in Hong Kong?
No. As at 23 September 2026 none of the 379 Walsin varistor part numbers is on our stock list, so every varistor is a quote. The ready stock list is a dated snapshot and is never live-synced.
Do you claim your varistors suit mining equipment?
No. We make no claim that any Walsin part is suitable for mining equipment or hazardous areas, none of our 28 datasheets names mining, and we hold no varistor datasheet. We hold no office or stock in Australia and give no compliance advice.