![\"\u03a3\u03c5\u03c3\u03ba\u03b5\u03c5\u03ae](\"https:\/\/www.britecelectric.com\/wp-content\/uploads\/2024\/08\/BR-25M-4P.jpg\")
<\/a>\r\n\u25cf \u03a4\u03cd\u03c0\u03bf\u03c2 1<\/strong> \u2014 fitted at the incoming service entrance to drain a direct lightning strike.<\/p>\r\n \r\n \u25cf \u03a4\u03cd\u03c0\u03bf\u03c2 2<\/strong> \u2014 fitted at distribution boards to limit surges as they spread through the building.<\/p>\r\n \u25cf \u03a4\u03cd\u03c0\u03bf\u03c2 3<\/strong> \u2014 fitted at the equipment to cut the last residual overvoltage the load sees.<\/p>\r\n\r\n Cascading is not optional on exposed or lightning-prone sites. A single Type 2 device at the main board cannot survive a direct strike, and a Type 1 alone leaves too much residual voltage for sensitive loads. The cascade closes both gaps: Type 1 drains the lightning current, Type 2 limits propagation through the board, and Type 3 finishes the job at the socket. The result is a lower voltage protection level (Up) at the equipment than any single stage could deliver. See our guide on when a Type 1 SPD is required<\/a> for site-risk triggers.<\/p>\r\n\r\n Follow this sequence when you lay out a coordinated protection scheme:<\/p>\r\n \u25cf Start at the origin<\/strong> \u2014 fit a Type 1 (or Type 1+2) SPD at the incoming service entrance, as close to the main switch as the wiring allows.<\/p>\r\n \u25cf Add Type 2 at each distribution board<\/strong> \u2014 every sub-board that feeds sensitive areas gets its own Type 2 SPD so surges are limited as they spread.<\/p>\r\n \u25cf Finish at the equipment<\/strong> \u2014 mount a Type 3 SPD within 10 m of the load, ideally at the socket or DIN position next to it.<\/p>\r\n \u25cf Keep the decoupling distance<\/strong> \u2014 leave roughly 10 m of wiring between stages, or insert a coordination inductor<\/a> when space is tight so the stages do not trip each other.<\/p>\r\n \u25cf Coordinate the backup protection<\/strong> \u2014 pair each SPD with the correct fuse or circuit breaker so a shorted SPD is isolated without dropping the feeder (see SPD and circuit breaker coordination<\/a>).<\/p>\r\n\r\n Need A Coordinated SPD Layout For Your Project?<\/p>\r\n Send Britec your single-line diagram and we will return a Type 1+2+3 cascade proposal with backup protection sized to IEC 61643.<\/p>\r\n Request A Coordination Quote<\/a><\/p>\r\n\r\n<\/div>\r\n SPDs must share the surge current, not compete for it. IEC 61643-12 defines energy coordination by the discharge capacity (Iimp for Type 1, In or Imax for Type 2 and Type 3) and the wiring impedance between stages. When the physical distance is below the decoupling rule, a coordination inductor adds the impedance artificially, letting the Type 1 fire first and the Type 3 stay dormant until needed. Skipping this step is the most common cause of nuisance tripping we see in the field.<\/p>\r\n\r\n Every SPD needs a backup device that clears a follow current but does not open on a normal surge. Britec supplies dedicated backup protectors and combined SPD plus MCB units, and our Type 1 design considerations<\/a> article covers sizing in detail. The backup must be coordinated with the SPD\u2019s short-circuit rating so the feeder stays live after a fault.<\/p>\r\n\r\n A coordinated scheme is only as good as the standard behind it. Design to IEC 61643-11 for SPD construction, IEC 61643-12 for selection and application, and IEC 62305 for the overall lightning-protection system. Specifying to these standards also keeps your project auditable for insurers and regulators. Our surge protector ratings guide<\/a> explains which numbers to quote in a tender.<\/p>\r\n\r\n \u25cf One SPD for the whole building<\/strong> \u2014 a single device cannot cover both a direct strike and point-of-use let-through.<\/p>\r\n \u25cf Ignoring the decoupling gap<\/strong> \u2014 stacking Type 1 and Type 3 with no distance or inductor causes both to trip.<\/p>\r\n \u25cf Wrong backup rating<\/strong> \u2014 an oversized fuse lets a failed SPD burn; an undersized one drops the feeder on every storm.<\/p>\r\n \u25cf Mixing brands without coordination data<\/strong> \u2014 only cascade devices whose manufacturer publishes coordination tables.<\/p>\r\n\r\n Britec Electric is a Wenzhou-based SPD manufacturer established in 2003, certified by Intertek SEMKO, TUV, and CE, and supplying Type 1, Type 1+2, Type 2, and Type 3 devices plus coordination inductors and backup protectors from one catalogue. That single-source coordination data is what lets your cascade actually work on paper and in the field. Explore the full Type 1, Type 2, and Type 3 ranges, or read how SPDs clamp transient overvoltage<\/a> before you specify.<\/p>\r\n\r\n Talk To A Britec SPD Engineer<\/p>\r\n Get a coordinated Type 1+2+3 SPD schedule, coordination inductor sizing, and backup-protector selection for your next project.<\/p>\r\n Contact Britec<\/a><\/p>\r\n\r\n<\/div>\r\n 1. What is surge protection coordination?<\/p>\r\n It is the layered arrangement of SPDs so each stage handles the surge energy it is rated for, preventing one device from being overloaded while the others stay idle.<\/p>\r\n 2. Can I install a Type 1, Type 2, and Type 3 SPD together?<\/p>\r\n Yes. That is the standard cascade for exposed sites: Type 1 at the entrance, Type 2 at sub-boards, and Type 3 at the equipment, with correct decoupling between them.<\/p>\r\n 3. What is the decoupling distance between SPD stages?<\/p>\r\n IEC 61643-12 typically calls for about 10 m of wiring between stages so the upstream device acts first. Where space is tight, a coordination inductor replaces that distance.<\/p>\r\n 4. Do I need a Type 1 SPD if I already have a Type 2?<\/p>\r\n On lightning-prone or directly struck sites, yes. A Type 2 cannot survive the 10\/350 \u00b5s lightning current that a Type 1 is built to drain.<\/p>\r\n 5. What does a coordination inductor do?<\/p>\r\n It adds artificial impedance between SPD stages so they trip in the right order when physical wiring distance is too short, avoiding nuisance operation.<\/p>\r\n 6. How do I coordinate an SPD with its backup fuse?<\/p>\r\n Size the backup (fuse or MCB) so it clears a failed SPD under short circuit but does not open during a normal surge, matching the SPD\u2019s discharge and short-circuit ratings.<\/p>\r\n 7. Which standard covers SPD coordination?<\/p>\r\n Coordination and application are covered by IEC 61643-12, with construction in IEC 61643-11 and the wider lightning system in IEC 62305.<\/p>\r\n 8. Can I mix SPD brands in one cascade?<\/p>\r\n Only if both manufacturers publish coordination data for the combination. Otherwise the stages may not share current correctly and could trip together.<\/p>\r\n 9. Where should a Type 3 SPD be installed?<\/p>\r\n As close as possible to the protected equipment, ideally within 10 m and at the final socket or DIN position feeding the load.<\/p>\r\n 10. How do I know my cascade is sized correctly?<\/p>\r\n Check Iimp for Type 1, In or Imax for Type 2 and 3, the voltage protection level Up against your equipment\u2019s withstand, and the backup rating against the prospective short-circuit current.<\/p>\r\n\r\n \u25cf Type 1 vs Type 1+2 vs Type 2 vs Type 3 SPD \u2014 Which to Choose<\/a><\/p>\r\n \u25cf What Is a Type 1 SPD and When Is It Required?<\/a><\/p>\r\n \u25cf SPD Type 1 Design Considerations For Electrical Engineers<\/a><\/p>\r\n \u25cf AC SPD Single Phase Coordination with Circuit Breakers<\/a><\/p>\r\n \u25cf How SPD Surge Protective Devices Handle Transient Overvoltage<\/a><\/p>","protected":false},"featured_media":2636,"parent":0,"menu_order":8,"template":"","meta":{"_acf_changed":false},"blog_category":[9],"class_list":["post-2635","blog","type-blog","status-publish","has-post-thumbnail","hentry","blog_category-industry-news"],"acf":{"des":"A practical guide to surge protection coordination: how to cascade Type 1, 2, and 3 SPDs with correct decoupling, backup protection, and IEC 61643 compliance.","txt":" Britec Electric has manufactured surge protective devices (SPDs) since 2003, and one question comes up in almost every panel-design review: how do you combine a Type 1 SPD<\/a>, a Type 2 SPD<\/a>, and a Type 3 SPD<\/a> so they protect each other instead of fighting each other? This guide explains surge protection coordination in plain engineering terms and gives you a repeatable cascade method you can apply to low-voltage systems.<\/p>\r\n\r\n Surge protection coordination is the practice of arranging SPDs in layers so that each device handles the surge energy it was built for, and no single device is asked to do the whole job. A direct lightning strike on the service entrance needs a heavy-duty Type 1 surge arrester<\/a>, while the sensitive PLC next to a socket needs a low-let-through Type 3 SPD<\/a>. Coordination makes sure the big device takes the hit first and the small device only cleans up what is left.<\/p>\r\n\r\n Before cascading, it helps to recall what each type is built for. The table below maps the type to its position in the installation.<\/p>\r\n\r\n![\"BR-T3](\"https:\/\/www.britecelectric.com\/wp-content\/uploads\/2024\/09\/BR-230-1.jpg\")
<\/a>\r\nWhy Cascade Type 1, 2, And 3 SPDs?<\/h2>\r\n
How To Cascade Type 1, 2, 3 SPDs (Step By Step)<\/h2>\r\n
Energy Coordination And Decoupling<\/h2>\r\n
Coordinating SPDs With Backup Protection And Circuit Breakers<\/h2>\r\n
Standards You Should Design To<\/h2>\r\n
Common Coordination Mistakes To Avoid<\/h2>\r\n
Why Specify Coordinated SPDs From Britec<\/h2>\r\n
\u03a3\u03c5\u03c7\u03bd\u03ad\u03c2 \u0395\u03c1\u03c9\u03c4\u03ae\u03c3\u03b5\u03b9\u03c2<\/h2>\r\n
Related Resources<\/h2>\r\n
What Is Surge Protection Coordination?<\/h2>\r\n
The Three SPD Types In A Cascade<\/h2>\r\n