20 mm square MOVs by Guiyang High-Tech Yige Electronic — UL 1449 Recognized, File E335803, with 22 recognized model grades from 100 V to 820 V varistor voltage.
The 20S series is a line of 20 mm square, epoxy-encapsulated zinc oxide varistors made by Guiyang High-Tech Yige Electronic Co., Ltd. for surge protective device (SPD) manufacturers and OEMs. Rated In 7 kA / Imax 15 kA (8/20 µs), the range covers varistor voltages from 100 V to 820 V in 22 model grades. The varistor discs are pressed, sintered, metallized, coated and tested in our own Guiyang plant — not bought in — which is how tolerances and surge ratings stay consistent from batch to batch. In North America, the series is supported by Flyboat Electronic LLC, the factory's sales and engineering center in Bellevue, WA.
| Certification wording | UL 1449 Recognized, File E335803 |
| Standards | UL 1449; CSA C22.2 No. 269.5-17 (Type 5 component recognition) |
| Certificate holder | GUIYANG YIGE HI-TEC ELECTRONIC CO LTD |
| UL Product iQ category | VZCA2 (United States), VZCA8 (Canada) |
| 20S coverage | 22 recognized grades, varistor voltages 100–820 V |
How to verify: go to UL Product iQ (productiq.ulprospector.com) and search file number E335803 — the public record lists every covered model. Our MOVs are UL Recognized components for building into end products such as SPDs; they are not "UL Listed" end products. Full coverage for all series is on the Certifications page.
Models are designated 20SK followed by a three-digit code. The code gives the varistor voltage: the first two digits, followed by as many zeros as the third digit says — 431 = 430 V, 122 = 1,200 V. (The maximum continuous working voltage of each grade is a separate, lower datasheet value.)
| Model | Varistor voltage | Model | Varistor voltage |
|---|---|---|---|
| 20SK101 | 100 V | 20SK121 | 120 V |
| 20SK151 | 150 V | 20SK181 | 180 V |
| 20SK201 | 200 V | 20SK221 | 220 V |
| 20SK241 | 240 V | 20SK271 | 270 V |
| 20SK301 | 300 V | 20SK331 | 330 V |
| 20SK361 | 360 V | 20SK391 | 390 V |
| 20SK431 | 430 V | 20SK471 | 470 V |
| 20SK511 | 510 V | 20SK561 | 560 V |
| 20SK621 | 620 V | 20SK681 | 680 V |
| 20SK711 | 710 V | 20SK751 | 750 V |
| 20SK781 | 780 V | 20SK821 | 820 V |
Column definitions: U1mA = varistor voltage at DC 1 mA; ΔU1mA = varistor-voltage tolerance; UAC / UDC = maximum continuous operating voltage; In = nominal discharge current (8/20 µs); Imax = maximum discharge current (8/20 µs); UP = clamping voltage at In, shown as reference value–ratio; ETM = maximum energy absorption (2 ms). Certification marks reproduce the catalog ratings tables.
| Model | U1mA (V) | ΔU1mA (%) | UAC (V) | UDC (V) | In (kA) | Imax (kA) | UP (V) | ETM (J) | UL | C-UL | TÜV |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 20SK101 | 100 | ±10 | 60 | 85 | 7 | 15 | 360-3.6 | 70 | ✓ | ✓ | — |
| 20SK121 | 120 | ±10 | 75 | 100 | 7 | 15 | 400-3.6 | 85 | ✓ | ✓ | — |
| 20SK151 | 150 | ±10 | 95 | 125 | 7 | 15 | 450-3.0 | 108 | ✓ | ✓ | — |
| 20SK181 | 180 | ±10 | 115 | 150 | 7 | 15 | 490-2.8 | 125 | ✓ | ✓ | — |
| 20SK201 | 200 | ±10 | 130 | 170 | 7 | 15 | 520-2.6 | 140 | ✓ | ✓ | — |
| 20SK221 | 220 | ±10 | 140 | 180 | 7 | 15 | 550-2.6 | 160 | ✓ | ✓ | — |
| 20SK241 | 240 | ±10 | 150 | 200 | 7 | 15 | 600-2.6 | 170 | ✓ | ✓ | — |
| 20SK271 | 270 | ±10 | 175 | 225 | 7 | 15 | 680-2.6 | 200 | ✓ | ✓ | — |
| 20SK301 | 300 | ±10 | 195 | 250 | 7 | 15 | 770-2.6 | 220 | ✓ | ✓ | — |
| 20SK331 | 330 | ±10 | 210 | 270 | 7 | 15 | 830-2.55 | 240 | ✓ | ✓ | — |
| 20SK361 | 360 | ±10 | 230 | 300 | 7 | 15 | 910-2.55 | 270 | ✓ | ✓ | — |
| 20SK391 | 390 | ±10 | 250 | 320 | 7 | 15 | 1000-2.55 | 300 | ✓ | ✓ | — |
| 20SK431 | 430 | ±10 | 275 | 350 | 7 | 15 | 1050-2.45 | 340 | ✓ | ✓ | — |
| 20SK471 | 470 | ±10 | 300 | 385 | 7 | 15 | 1100-2.4 | 360 | ✓ | ✓ | — |
| 20SK511 | 510 | ±10 | 320 | 410 | 7 | 15 | 1150-2.35 | 390 | ✓ | ✓ | — |
| 20SK561 | 560 | ±10 | 350 | 450 | 7 | 15 | 1250-2.35 | 420 | ✓ | ✓ | — |
| 20SK621 | 620 | ±10 | 385 | 505 | 7 | 15 | 1450-2.3 | 460 | ✓ | ✓ | — |
| 20SK681 | 680 | ±10 | 420 | 560 | 7 | 15 | 1600-2.3 | 460 | ✓ | ✓ | — |
| 20SK711 | 710 | ±10 | 440 | 585 | 7 | 15 | 1650-2.3 | 470 | ✓ | ✓ | — |
| 20SK751 | 750 | ±10 | 460 | 615 | 7 | 15 | 1700-2.3 | 475 | ✓ | ✓ | — |
| 20SK781 | 780 | ±10 | 485 | 640 | 7 | 15 | 1750-2.3 | 480 | ✓ | ✓ | — |
| 20SK821 | 820 | ±10 | 510 | 670 | 7 | 15 | 1800-2.3 | 485 | ✓ | ✓ | — |
Low-clamping range, optimised for lower clamping voltage at In. Same column definitions as the standard table above.
| Model | U1mA (V) | ΔU1mA (%) | UAC (V) | UDC (V) | In (kA) | Imax (kA) | UP (V) | ETM (J) | UL | C-UL | TÜV |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 20SK431 | 430 | ±10 | 275 | 350 | 7 | 15 | 990-2.2 | 340 | ✓ | ✓ | — |
| 20SK471 | 470 | ±10 | 300 | 385 | 7 | 15 | 1070-2.2 | 360 | ✓ | ✓ | — |
| 20SK511 | 510 | ±10 | 320 | 410 | 7 | 15 | 1150-2.2 | 390 | ✓ | ✓ | — |
| 20SK561 | 560 | ±10 | 350 | 450 | 7 | 15 | 1250-2.15 | 420 | ✓ | ✓ | — |
| 20SK621 | 620 | ±10 | 385 | 505 | 7 | 15 | 1350-2.1 | 460 | ✓ | ✓ | — |
| 20SK681 | 680 | ±10 | 420 | 560 | 7 | 15 | 1520-2.1 | 460 | ✓ | ✓ | — |
| 20SK711 | 710 | ±10 | 440 | 585 | 7 | 15 | 1600-2.1 | 470 | ✓ | ✓ | — |
| 20SK751 | 750 | ±10 | 460 | 615 | 7 | 15 | 1700-2.1 | 475 | ✓ | ✓ | — |
| 22SK781 | 780 | ±10 | 485 | 640 | 7 | 15 | 1760-2.1 | 480 | ✓ | ✓ | — |
| 22SK821 | 820 | ±10 | 510 | 670 | 7 | 15 | 1800-2.08 | 485 | ✓ | ✓ | — |
Notes: the last two rows of this table are misprinted in the catalog with a 22SK prefix (“22SK781” / “22SK821”); by position and values they are the 20S rows — shown as printed.
Every grade has a full datasheet (electrical parameters, surge ratings, dimensions), available on request. For samples and design-in support: North America — Thomas Dong, Flyboat Electronic LLC; China — Colin Fei. See the Contact page or the buyer FAQ.
One boundary worth stating plainly: these are bare MOV components with no integrated thermal protection, and they are not drop-in replacements for thermally protected TMOV devices. Disconnection belongs to the SPD design; where a design calls for it at the device level, we supply protection modules with built-in disconnectors — see Products.
