{"product_id":"mov20d201k-20ohm-4a-20mm-radial-leaded-varistor","title":"MOV-20D201K 20ohm 4A 20mm Radial Leaded Varistor - Avalon PSU","description":"\u003ch2\u003eMOV-20D201K Metal-Oxide Varistor | 20mm Radial-Leaded Surge Suppressor for Avalon Miner PSU\u003c\/h2\u003e\n\u003cp\u003eThe \u003cstrong\u003eMOV-20D201K\u003c\/strong\u003e is a \u003cstrong\u003e20mm radial-leaded metal-oxide varistor (MOV)\u003c\/strong\u003e used on \u003cstrong\u003eAvalon Miner power supplies\u003c\/strong\u003e for AC-line surge protection. Defends downstream PSU circuitry against transient overvoltages — lightning strikes, power contact events, and inductive transients on the mains supply. \u003cstrong\u003eFast response time\u003c\/strong\u003e, \u003cstrong\u003ehigh energy absorption\u003c\/strong\u003e, low clamping ratio, and no freewheeling current after clamp release.\u003c\/p\u003e\n\u003cp\u003eDrop-in replacement when the original sacrifices itself absorbing a surge (its job) or degrades from years of mains transients. The 20mm disc has higher energy capacity than the smaller 14mm class — better for the Avalon PSU input stage where surge tolerance matters across multi-kW switching.\u003c\/p\u003e\n\u003ch3\u003eWhen to Replace the MOV-20D201K\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePSU dead after a known voltage event\u003c\/strong\u003e — surge, lightning, utility transient — varistor often sacrifices itself and shorts to protect downstream circuitry.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInput fuse blown\u003c\/strong\u003e with no other visible damage — varistor shorted, took out the fuse on the next surge.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVisible cracking, blackening, or charring\u003c\/strong\u003e on the disc body or epoxy coating.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBurn marks on the PCB\u003c\/strong\u003e around the varistor footprint after a fault event.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePreventive replacement\u003c\/strong\u003e on Avalon PSUs returning from sites with poor mains quality.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eMOV-20D201K Specifications\u003c\/h4\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eFeature\u003c\/th\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003ePart Number\u003c\/td\u003e\n\u003ctd\u003eMOV-20D201K\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCategory\u003c\/td\u003e\n\u003ctd\u003eMetal Oxide Varistor (MOV)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDisc Diameter\u003c\/td\u003e\n\u003ctd\u003e20mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMounting\u003c\/td\u003e\n\u003ctd\u003eRadial-leaded through-hole\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Voltage (V1mA) Range\u003c\/td\u003e\n\u003ctd\u003e8V to 1800V (family)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eResponse Time\u003c\/td\u003e\n\u003ctd\u003eFast\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEnergy Absorption\u003c\/td\u003e\n\u003ctd\u003eHigh\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Temperature\u003c\/td\u003e\n\u003ctd\u003e-55°C to +85°C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eStorage Temperature\u003c\/td\u003e\n\u003ctd\u003e-55°C to +125°C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBody Finish\u003c\/td\u003e\n\u003ctd\u003eNickel-plated\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompatible PSU\u003c\/td\u003e\n\u003ctd\u003eAvalon Miner power supplies\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003e\u003c\/h3\u003e\n\u003ch3\u003eFAQ — MOV-20D201K Varistor\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eQ: Why does the varistor short when it absorbs a surge?\u003c\/strong\u003e\u003cbr\u003eA: That's its design behaviour — a MOV clamps overvoltage by conducting the surge to neutral. Big surges fuse the internal granular structure into a low-impedance path, sacrificing the part to save the rest of the PSU. Always replace a sacrificed varistor along with the input fuse.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: 20mm vs 14mm MOV — does the size matter?\u003c\/strong\u003e\u003cbr\u003eA: Yes — disc diameter sets the energy capacity. The 20mm class handles higher single-event energy than the 14mm equivalent. For the Avalon PSU input stage, stick with 20mm — substituting smaller risks under-rated protection.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: How do I test if the existing varistor is still healthy?\u003c\/strong\u003e\u003cbr\u003eA: Power off and isolated, measure resistance across the leads with a high-range DMM. Healthy MOV reads OL (megohms+). Shorted or partially-conducting reading = degraded varistor, replace.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: Bulk pricing for Avalon PSU repair benches?\u003c\/strong\u003e\u003cbr\u003eA: Yes — email contact@lys-sz.com for volume pricing on MOV-20D201K plus matched input fuses for Avalon PSU repair kits.\u003c\/p\u003e\n\u003ch3\u003eRelated products\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"\/products\/14d681k-varistor-replacement-avalon-avalonminer-psu3300-03-power-supply\"\u003e14D681K Varistor (Avalon PSU3300-03)\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/s14k300-metal-oxide-varistor-bitmain-power-supply-unit-apw9-repair\"\u003eS14K300 Varistor (Bitmain APW9)\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/tvr14511-surge-protection-varistor-antminer-bitmain-apw12-power-supply-repair\"\u003eTVR 14511 Varistor (Bitmain APW12)\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/avalon-psu-3300w-canaan-power-supply-a1166-a1166pro-a1246\"\u003eAvalon PSU3300-03 Plus (A1066 \/ A1166 \/ A1246)\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eAvalon PSU repair benches stocking MOV-20D201K varistors by the strip? Email \u003ca href=\"mailto:contact@lys-sz.com\"\u003econtact@lys-sz.com\u003c\/a\u003e for bulk pricing. Worldwide shipping from our Shenzhen warehouse.\u003c\/p\u003e","brand":"LYS Shenzhen","offers":[{"title":"Default Title","offer_id":42637389430963,"sku":null,"price":0.18,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0627\/6710\/4179\/files\/MOV-20D201K-20ohm-4A-Radial-Leaded-Varistor.webp?v=1774225745","url":"https:\/\/lys-sz.com\/products\/mov20d201k-20ohm-4a-20mm-radial-leaded-varistor","provider":"LYS Shenzhen","version":"1.0","type":"link"}