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Short answer: for PV projects that need UL-listed DC disconnects, the ten manufacturers to know in 2026 are ABB, Eaton, Socomec, Mersen, Littelfuse, Santon, Kraus & Naimer, IMO Precision Controls, Benedikt & Jäger and ZJBENY. The first five dominate large UL 98B disconnects for combiner and recombiner boxes, rated up to 1,500 VDC and hundreds of amps. The last five specialise in small UL 508i isolators of the kind built into string inverters and rooftop enclosures. Picking the right standard is more important than picking the brand.

Last updated: October 2026. For every product named below we checked the maker’s datasheet or certificate page for the UL standard and, where published, the UL file number. A UL file number lets anyone confirm a listing in UL Product iQ, so we include them where available.

UL 508i or UL 98B: which one your drawing needs

UL 508iUL 98B
What it coversManual disconnect switches for PV, derived from industrial control switch rulesEnclosed and dead-front switches for PV systems
Typical current13 to 85 A30 to 2,000 A
Typical voltage600 to 1,500 VDC (model dependent)600, 1,000 or 1,500 VDC
Where it goesInside string inverters, rooftop isolators, small combinersCombiner and recombiner boxes, inverter DC input, storage
Who buys itInverter OEMs, residential and small commercial installersEPCs, utility and C&I contractors, box builders

The two are not interchangeable. An inspector who expects a UL 98B disconnect on a 400 A recombiner will reject a UL 508i part, however well made. The reverse is also true for inverter OEMs, where UL 98B parts are too big and too costly.

Comparison of the ten manufacturers

ManufacturerProduct lineUL standardPublished ratingUL file
ABBOTDCUL 508i (16 to 32 A); UL 98B (100 to 1,000 A)600 VDC (small); 1,000 VDC (large)E4466875; E354681
EatonSolar safety switchesUL 98B30 to 1,200 A; 600 / 1,000 / 1,500 VDCAsk
SocomecINOSYS LBS; SIRCO PVUL 98B100 to 1,200 A (INOSYS); up to 2,000 A (SIRCO PV); 1,500 VDCE346418
MersenMD seriesUL 98B100 to 400 A; 1,000 / 1,500 VDCE466972
LittelfuseLS6R / LS7RUL 98B250 A, 1,500 VDC, 10 kAE511898
SantonX-type (XBUE, XBU, XBUHP, XC)UL 508iUp to 1,500 V at 30 A (XC)Ask
Kraus & NaimerKGD40 / KGD40BUL 508i600 V / 40 A (UL)E365898
IMO Precision ControlsSI / SIMUL 508iModel dependentE362605
Benedikt & JägerLS16 to LS65UL 508iUp to 85 AE359344
ZJBENYBYS / BYSS; BH-250UL 508i; UL listing on BH-2501,000 V at 16 to 30 A; 1,500 V at 13 A; BH-250: 1,500 V / 250 AAsk

Large UL 98B disconnects

1. ABB

ABB’s OTDC family is the only range here that spans both standards. The small 16 to 32 A OTDC units are UL 508i listed at 600 VDC under file E4466875. Note the voltage: they are not 1,000 V parts in UL terms, even though IEC ratings are higher. The 100 to 1,000 A OTDC disconnects are UL 98B listed (file E354681) at 1,000 VDC. ABB markets 1,500 V versions too, but describes that rating as self-certified, so check what your inspector will accept.

2. Eaton

Eaton offers solar safety switches from 30 to 1,200 A at 600, 1,000 and 1,500 VDC, all to UL 98B, bidirectional for storage applications, and made in America. Eaton describes its 1,500 VDC switch as an industry first. For US utility and C&I contractors who standardise on Eaton switchgear, these switches keep the whole AC and DC side under one supplier.

3. Socomec

Socomec’s INOSYS LBS load-break switches are UL 98B listed (Guide WHVA, file E346418) from 100 to 1,200 A at 1,500 VDC, with the current certificate dated 27 June 2025. Its SIRCO PV range goes higher, up to 2,000 A at 1,500 VDC under the same file, and a motorised SIRCO MOT DC version allows remote switching. Socomec is a frequent pick for central-inverter and battery container builders.

4. Mersen

Mersen, better known for fuses, makes the MD series of UL 98B PV disconnects (file E466972), rated 100 to 400 A under UL at 1,000 or 1,500 VDC. One warning from Mersen’s own catalogue: its UL 98 fusible switches are not rated for PV, so make sure the order code is from the MD series.

5. Littelfuse

Littelfuse’s LS6R (grounded systems) and LS7R (ungrounded) DC disconnects are rated 250 A at 1,500 VDC with a 10 kA short-circuit rating, listed to UL 98B under Guide WHVA, file E511898. The datasheet gives Spain as the country of origin. The range also covers battery disconnection in storage containers, which makes it useful for hybrid PV and storage sites.

Small UL 508i isolators

6. Santon

Santon, part of the UK-listed discoverIE group, is one of the biggest names in inverter-mounted DC switches. It reports more than 12 million units in use and about 2 million shipped each year to inverter OEMs. Its X-type OEM switches (XBUE, XBU, XBUHP, XC) are UL 508i: the XBUHP reaches 1,500 V at 13 A, and the XC reaches 1,500 V at 30 A or 1,000 V at 50 A. Santon’s Silios D enclosed isolator, by contrast, is IEC 60947 only, so it is not a UL part.

7. Kraus & Naimer

The Austrian switch maker lists its KGD40 and KGD40B PV switches under UL file E365898. Under IEC they reach 50 A at 1,000 VDC, but the UL 508i rating is 600 V at 40 A. That gap between IEC and UL ratings is common, and it is the reason to read the UL certificate rather than the headline datasheet figure.

8. IMO Precision Controls

UK-based IMO launched its SI and SIM true-DC isolators in 2010 and reports more than 6 million units installed (its UK site says 8 million). They are UL listed under file E362605. IMO is a common choice for rooftop isolators in markets that require a separate DC switch next to the array.

9. Benedikt & Jäger

Benedikt & Jäger (B&J), also from Austria, makes the LS16 to LS65 range, UL 508i listed under file E359344, with ratings up to 85 A. The company claims it received the first UL 508i approval worldwide. Higher current per pole makes the range useful for small commercial combiners.

10. ZJBENY

ZJBENY (BENY) of Zhejiang is the Chinese name that belongs on a global list. Its BYS series received UL 508i certification in July 2016, which BENY announced in October 2017 as the first UL 508i DC switch from a Chinese maker. Current BYSS models are rated 1,000 V at 16 to 30 A and 1,500 V at 13 A, and the BH-250-2P is UL listed at 1,500 V and 250 A. For more Chinese options, and how to check their claims, see our guide to China UL isolation switch suppliers.

How to verify a UL listing in two minutes

  1. Ask the supplier for the UL file number (it starts with E) and the exact model code.
  2. Search the file number in UL Product iQ (productiq.ulprospector.com).
  3. Check that the listing names the same company, the same model family, and the voltage and current you need, under the UL standard your design calls for.
  4. If the file belongs to another company, ask whether the product is listed under a multiple-listing arrangement. Without that, the marking may not be valid.

ShineTong supplies DC isolator switches and combiner boxes for distributors and EPCs. We state the certification of each model on request and do not quote UL ratings we cannot document. For related protection devices, see our rankings of surge protection device manufacturers, GFCI breaker manufacturers and DC contactor manufacturers.

Frequently asked questions

What is the difference between UL 508i and UL 98B?

UL 508i covers manual disconnect switches for PV, usually small units up to about 85 A built into inverters or rooftop enclosures. UL 98B covers larger enclosed and dead-front PV switches, typically 30 A to 2,000 A, used in combiner and recombiner boxes. Inspectors expect the standard that matches the application.

Is an IEC 60947-3 DC isolator acceptable in the US?

Not on its own. US installations under NEC Article 690 need listed equipment, which in practice means UL 508i or UL 98B for PV disconnects. IEC certification does not substitute for a UL listing.

Which UL DC disconnects are rated for 1,500 VDC?

Among the products above: Eaton solar safety switches, Socomec INOSYS LBS and SIRCO PV, Mersen MD, Littelfuse LS6R/LS7R, Santon XBUHP and XC, and ZJBENY BYSS 1,500 V and BH-250. ABB describes its 1,500 V OTDC rating as self-certified.

How do I check if a disconnect switch is really UL listed?

Get the UL file number and model code, search the file in UL Product iQ, and confirm the company name, model family and ratings match. A UL logo on a website or datasheet is not proof.

Why is the UL voltage rating lower than the IEC rating on the same switch?

UL and IEC test differently, so the same switch can carry, for example, 1,000 VDC under IEC but 600 VDC under UL 508i. Use the UL rating for any North American design.

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