{"id":3458,"date":"2026-05-19T09:00:00","date_gmt":"2026-05-19T01:00:00","guid":{"rendered":"https:\/\/eqsvq3fzct.wpdns.site\/blog\/best-lsig-circuit-breaker-for-your-needs\/"},"modified":"2026-10-20T10:46:00","modified_gmt":"2026-10-20T02:46:00","slug":"best-lsig-circuit-breaker-for-your-needs","status":"publish","type":"post","link":"https:\/\/w9-group.com\/ja\/blog\/best-lsig-circuit-breaker-for-your-needs\/","title":{"rendered":"\u304a\u5ba2\u69d8\u306e\u30cb\u30fc\u30ba\u306b\u6700\u9069\u306aLsig\u30b5\u30fc\u30ad\u30c3\u30c8\u30d6\u30ec\u30fc\u30ab\u306f\u4f55\u3067\u3059\u304b\uff1f"},"content":{"rendered":"

LSIG is often used to describe long-time, short-time, instantaneous and ground-fault protection in an electronic trip unit. A buyer asking for the best LSIG circuit breaker needs a settings and coordination answer, not an unsupported product ranking. <\/p>\n

Quick answer: define each protection function, its adjustable range, delay, tolerances, sensing arrangement and coordination target. Confirm whether the model actually provides L, S, I and G, because not every electronic trip unit includes every function. Ground-fault protection is also not the same as every residual-current protection method.<\/p>\n

\"\u304a\u5ba2\u69d8\u306e\u30cb\u30fc\u30ba\u306b\u6700\u9069\u306aLsig\u30b5\u30fc\u30ad\u30c3\u30c8\u30d6\u30ec\u30fc\u30ab\u306f\u4f55\u3067\u3059\u304b\uff1f\"<\/figure>\n

LSIG Protection Functions<\/h2>\n

Long-time protection addresses sustained overload; short-time protection supports selective coordination for higher fault levels; instantaneous protection responds quickly to very high current; ground-fault protection detects the configured ground-fault condition. must be mapped to the project protection study and not copied as a generic label.<\/p>\n

\"\u304a\u5ba2\u69d8\u306e\u30cb\u30fc\u30ba\u306b\u6700\u9069\u306aLsig\u30b5\u30fc\u30ad\u30c3\u30c8\u30d6\u30ec\u30fc\u30ab\u306f\u4f55\u3067\u3059\u304b\uff1f\"<\/figure>\n

Settings and selectivity<\/h2>\n

Pickup and delay settings interact with upstream and downstream breakers. A lower pickup may protect conductors but reduce selectivity; a longer delay may improve coordination but increase withstand requirements. Record the approved setting file, adjustment authority and test method.<\/p>\n

\"\u4e2d\u56fd\u306e\u30d9\u30b9\u30c8Lsig\u30b5\u30fc\u30ad\u30c3\u30c8\u30d6\u30ec\u30fc\u30ab\u306e\u7279\u9577\u3068\u5229\u70b9\u306f\u4f55\u3067\u3059\u304b\uff1f\"<\/figure>\n

Ground-Fault Protection Scope<\/h2>\n

Ground-fault protection can use a sensing and trip arrangement defined by the breaker. It should not be presented as a universal substitute for \u6b8b\u7559\u96fb\u6d41\u4fdd\u8b77<\/strong>, insulation monitoring or an earthing design. See MCCB\u306e\u30ab\u30c6\u30b4\u30ea\u30fc<\/a> \u8a72\u5f53\u3059\u308b\u88fd\u54c1\u307e\u305f\u306f\u30ac\u30a4\u30c9\u30e9\u30a4\u30f3\u306b\u3064\u3044\u3066\u3002.<\/p>\n

\"\u73fe\u4ee3\u306e\u96fb\u6c17\u30b7\u30b9\u30c6\u30e0\u306b\u304a\u3051\u308bLsig\u906e\u65ad\u5668\u306e\u5229\u70b9\u3092\u63a2\u308b\"<\/figure>\n
\"\u4e2d\u56fd\u5927\u624b\u30e1\u30fc\u30ab\u30fc\u306e\u6700\u9ad8\u54c1\u8cea\u306eICB\u9ad8\u51fa\u529b\u30b3\u30f3\u30c7\u30f3\u30b5\u3092\u4e16\u754c\u4e2d\u306e\u30d0\u30a4\u30e4\u30fc\u306b\u63d0\u4f9b\"<\/figure>\n

Define what best means for an LSIG feeder<\/h2>\n

The best fit is the release whose permitted functions and ranges meet the approved study and can be tested and maintained by the facility. Check the sensor arrangement, neutral treatment and any dependency on auxiliary power. A release with more menu options can still be unsuitable if its minimum pickup or delay does not meet the circuit duty.<\/p>\n\n\n\n\n\n\n\n\n\n
\u6c7a\u5b9a<\/th>\n\u8a3c\u62e0<\/th>\n<\/tr>\n<\/thead>\n
\u9577\u671f\u7684\u306a\u4fdd\u8b77<\/td>\nLoad, conductor limit and curve<\/td>\n<\/tr>\n
Short-time coordination<\/td>\nDownstream curves and withstand<\/td>\n<\/tr>\n
Instantaneous response<\/td>\n\u30a4\u30f3\u30c0\u30fc\u30b9\u30a4\u30c3\u30c1\u30f3\u30b0\u96fb\u6d41\u304a\u3088\u3073\u53ef\u7528\u4e0d\u826f\u96fb\u6d41<\/td>\n<\/tr>\n
Ground-fault function<\/td>\nEarthing and sensing diagram<\/td>\n<\/tr>\n
\u78ba\u8a8d<\/td>\nExact test method and setting record<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Do not assume that every electronic release includes G or that the ground-fault function supplies required additional shock protection. Obtain the exact W9 model and release manual and compare it with the intended protection objective.<\/p>\n

\"Ultimate<\/figure>\n

LSIG Configuration Evidence<\/h2>\n

Request the exact trip-unit manual, setting table, sensor arrangement, accessory list and test documentation. W9’s electronic and LCD MCCB<\/a> ranges should be evaluated by model code and rating; the category page is a starting point, not a blanket specification. See electronic MCCB information for the relevant product or guidance.<\/p>\n

\"How<\/figure>\n

Selection checklist<\/h2>\n

List \u5b9a\u683c\u96fb\u6d41<\/strong>, voltage, poles, fault current, coordination target, L\/S\/I\/G ranges, ground-fault sensing, auxiliary supply, communications and commissioning records. See request LSIG documentation for the relevant product or guidance.<\/p>\n

\"10<\/figure>\n

LSIG Selection Records<\/h2>\n

\u8a2d\u8a08\u6bb5\u968e\u3067\u306f\u3001\u30ab\u30bf\u30ed\u30b0\u756a\u53f7\u3092\u9078\u629e\u3059\u308b\u524d\u306b\u3001\u96fb\u6c17\u8ca0\u8377\u3068\u672a\u89e3\u6c7a\u306e\u4eee\u5b9a\u3092\u66f8\u304d\u7559\u3081\u3066\u304f\u3060\u3055\u3044\u3002\u30b7\u30b9\u30c6\u30e0\u96fb\u5727\u3001\u5468\u6ce2\u6570\u3001\u9023\u7d9a\u96fb\u6d41\u3001\u30dd\u30fc\u30eb\u6570\u3092\u8a18\u8f09\u3057\u3066\u304f\u3060\u3055\u3044\u3002, \u5c06\u6765\u7684\u306a\u6545\u969c\u96fb\u6d41<\/strong>, \u30ed\u30fc\u30c9\u30d7\u30ed\u30d5\u30a1\u30a4\u30eb\u3001\u5468\u56f2\u6761\u4ef6\u3001\u304a\u3088\u3073\u7b50\u4f53\u69cb\u6210\u3002\u3053\u308c\u306b\u3088\u308a\u3001\u3059\u3079\u3066\u306e\u898b\u7a4d\u66f8\u306b\u5171\u901a\u306e\u57fa\u6e96\u304c\u8a2d\u5b9a\u3055\u308c\u3001\u7570\u306a\u308b\u69cb\u6210\u3067\u7570\u306a\u308b\u8cea\u554f\u306b\u56de\u7b54\u3059\u308b\u3088\u3046\u306a\u30b5\u30d7\u30e9\u30a4\u30e4\u30fc\u3092\u9632\u6b62\u3057\u307e\u3059\u3002.<\/p>\n

\u898b\u7a4d\u3082\u308a\u6bb5\u968e\u3067\u306f\u3001\u5236\u5fa1\u3055\u308c\u305f\u30c7\u30fc\u30bf\u30b7\u30fc\u30c8\u3001\u30e2\u30c7\u30eb\u30b3\u30fc\u30c9\u3001\u6982\u8981\u56f3\u9762\u3001\u7aef\u672b\u914d\u7f6e\u3001\u4ed8\u5c5e\u54c1\u306e\u30b9\u30b1\u30b8\u30e5\u30fc\u30eb\u3001\u8a2d\u5b9a\u7bc4\u56f2\u3001\u30c6\u30b9\u30c8\u7bc4\u56f2\u3001\u304a\u3088\u3073\u30c9\u30ad\u30e5\u30e1\u30f3\u30c8\u306e\u6539\u8a02\u306b\u3064\u3044\u3066\u3054\u4f9d\u983c\u304f\u3060\u3055\u3044\u3002\u56fa\u5b9a\u88c5\u7f6e\u3001\u53d6\u308a\u5916\u3057\u53ef\u80fd\u306a\u88c5\u7f6e\u3001\u901a\u4fe1\u6a5f\u80fd\u3092\u6301\u3064\u88c5\u7f6e\u306f\u3001\u4e3b\u96fb\u6e90\u96fb\u5727\u304c\u540c\u3058\u5834\u5408\u3067\u3082\u3001\u7570\u306a\u308b\u7bc4\u56f2\u3068\u306a\u308a\u307e\u3059\u3002\u30d1\u30cd\u30eb\u30e1\u30fc\u30ab\u30fc\u304c\u63d0\u4f9b\u3059\u3079\u304d\u9805\u76ee\u3001\u30aa\u30d7\u30b7\u30e7\u30f3\u9805\u76ee\u3001\u304a\u3088\u3073\u5fc5\u9808\u9805\u76ee\u3092\u8a18\u9332\u3057\u3066\u304f\u3060\u3055\u3044\u3002.<\/p>\n

\u30a2\u30bb\u30f3\u30d6\u30ea\u304a\u3088\u3073\u8a66\u904b\u8ee2\u6bb5\u968e\u3067\u306f\u3001\u7269\u7406\u7684\u7279\u6027\u3001\u53d6\u308a\u4ed8\u3051\u3001\u914d\u7dda\u3001\u30e9\u30d9\u30eb\u3001\u30c8\u30eb\u30af\u3001\u8a2d\u5b9a\u3001\u304a\u3088\u3073\u6a5f\u80fd\u30c1\u30a7\u30c3\u30af\u3092\u627f\u8a8d\u6e08\u307f\u306e\u30d5\u30a1\u30a4\u30eb\u3068\u6bd4\u8f03\u3057\u3066\u78ba\u8a8d\u3057\u307e\u3059\u3002\u7533\u8acb\u304c\u516c\u958b\u3055\u308c\u305f\u88fd\u54c1\u306e\u7bc4\u56f2\u5916\u3067\u3042\u308b\u5834\u5408\u306f\u3001\u30ea\u30ea\u30fc\u30b9\u3092\u505c\u6b62\u3057\u3001\u6280\u8853\u7684\u306a\u8aac\u660e\u3092\u5f97\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002\u3053\u306e\u8a3c\u62e0\u306f\u3001\u4e00\u822c\u7684\u306a\u300c\u30c8\u30c3\u30d7\u300d\u30e9\u30d9\u30eb\u3088\u308a\u3082\u4fa1\u5024\u304c\u9ad8\u3044\u305f\u3081\u3001\u6b21\u306e\u6280\u8853\u8005\u304c\u305d\u306e\u30c7\u30d0\u30a4\u30b9\u304c\u306a\u305c\u627f\u8a8d\u3055\u308c\u305f\u306e\u304b\u3092\u7406\u89e3\u3059\u308b\u306e\u306b\u5f79\u7acb\u3061\u307e\u3059\u3002.<\/p>\n\n\n\n\n\n\n\n\n
\u30d7\u30ed\u30b8\u30a7\u30af\u30c8\u6bb5\u968e<\/th>\n\u7de0\u3081\u304f\u304f\u308b\u8cea\u554f<\/th>\n\u4fdd\u6301\u3059\u3079\u304d\u8a3c\u62e0<\/th>\n<\/tr>\n<\/thead>\n
\u30c7\u30b6\u30a4\u30f3<\/td>\n\u3069\u306e\u3088\u3046\u306a\u7fa9\u52d9\u304a\u3088\u3073\u904e\u5931\u30ec\u30d9\u30eb\u3092\u4fdd\u8b77\u3057\u306a\u3051\u308c\u3070\u306a\u3089\u306a\u3044\u306e\u3067\u3057\u3087\u3046\u304b\uff1f<\/td>\n\u30ed\u30fc\u30c9\u30b9\u30b1\u30b8\u30e5\u30fc\u30eb\u3068\u4fdd\u8b77\u306b\u95a2\u3059\u308b\u8abf\u67fb<\/td>\n<\/tr>\n
\u898b\u7a4d\u3082\u308a<\/td>\n\u3069\u306e\u30e2\u30c7\u30eb\u3068\u4ed8\u5c5e\u54c1\u304c\u540c\u68b1\u3055\u308c\u3066\u3044\u307e\u3059\u304b\uff1f<\/td>\n\u69cb\u6210\u30b7\u30fc\u30c8\u304a\u3088\u3073\u6539\u8a02\u7ba1\u7406\u30c7\u30fc\u30bf\u30b7\u30fc\u30c8<\/td>\n<\/tr>\n
\u30a2\u30bb\u30f3\u30d6\u30ea<\/td>\n\u3053\u306e\u30c7\u30d0\u30a4\u30b9\u306f\u691c\u8a3c\u6e08\u307f\u306e\u30dc\u30fc\u30c9\u69cb\u6210\u306b\u9069\u5408\u3057\u307e\u3059\u304b\uff1f<\/td>\n\u56f3\u9762\u3001\u914d\u7dda\u304a\u3088\u3073\u7d44\u7acb\u8a18\u9332<\/td>\n<\/tr>\n
\u7a3c\u50cd\u958b\u59cb<\/td>\n\u8a2d\u5b9a\u3084\u6a5f\u80fd\u306f\u627f\u8a8d\u3055\u308c\u305f\u8a2d\u8a08\u3068\u4e00\u81f4\u3057\u3066\u3044\u307e\u3059\u304b\uff1f<\/td>\n\u30c6\u30b9\u30c8\u8a18\u9332\u3001\u8a2d\u5b9a\u30d5\u30a1\u30a4\u30eb\u3001\u304a\u3088\u3073\u69cb\u7bc9\u6e08\u307f\u30b9\u30b1\u30b8\u30e5\u30fc\u30eb<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\u3042\u3089\u3086\u308b\u8acb\u6c42\u306b\u5bfe\u3057\u3066\u66f8\u9762\u306b\u3088\u308b\u5883\u754c\u7dda\u3092\u8a2d\u5b9a\u3057\u3066\u304f\u3060\u3055\u3044\u3002\u88fd\u54c1\u898f\u683c\u306f\u8a2d\u7f6e\u8a3c\u660e\u66f8\u3067\u306f\u3042\u308a\u307e\u305b\u3093\u3002\u8868\u793a\u88c5\u7f6e\u306f\u81ea\u52d5\u7684\u306b\u901a\u4fe1\u30b7\u30b9\u30c6\u30e0\u3067\u306f\u3042\u308a\u307e\u305b\u3093\u3002AC\u5b9a\u683c\u306fDC\u5b9a\u683c\u3067\u306f\u3042\u308a\u307e\u305b\u3093\u3002\u307e\u305f\u3001\u30b5\u30d7\u30e9\u30a4\u30e4\u30fc\u30ab\u30c6\u30b4\u30ea\u30fc\u30da\u30fc\u30b8\u306f\u30d7\u30ed\u30b8\u30a7\u30af\u30c8\u56fa\u6709\u306e\u627f\u8a8d\u3067\u306f\u3042\u308a\u307e\u305b\u3093\u3002\u8a3c\u62e0\u304c\u4e0d\u8db3\u3057\u3066\u3044\u308b\u5834\u5408\u306f\u3001\u305d\u306e\u8a18\u8ff0\u3092\u6587\u66f8\u307e\u305f\u306f\u6280\u8853\u78ba\u8a8d\u306e\u8981\u6c42\u306b\u5909\u63db\u3057\u3066\u304f\u3060\u3055\u3044\u3002\u3053\u306e\u6163\u884c\u306b\u3088\u308a\u3001\u672a\u56de\u7b54\u9805\u76ee\u304c\u8cfc\u5165\u767a\u6ce8\u524d\u306b\u78ba\u8a8d\u3067\u304d\u308b\u305f\u3081\u3001\u8abf\u9054\u304c\u3088\u308a\u8fc5\u901f\u306b\u306a\u308a\u307e\u3059\u3002.<\/p>\n

\u3088\u304f\u3042\u308b\u8cea\u554f<\/h2>\n

Which LSIG breaker is best for my feeder?<\/h3>\n

Select from the system study, required functions, setting ranges and installation conditions. No universal ranking applies without those inputs.<\/p>\n

Does every electronic MCCB include all LSIG functions?<\/h3>\n

No. Confirm the exact supplied release and optional functions in its manual and order code.<\/p>\n

Can longer delay always improve protection?<\/h3>\n

No. It may support discrimination but increases the period of fault exposure. Review withstand and fault-energy consequences.<\/p>\n

What evidence is needed for ground-fault settings?<\/h3>\n

Use the earthing design, sensing and neutral diagram, required sensitivity and \u8abf\u6574\u7814\u7a76<\/strong>. Confirm the test procedure for that release.<\/p>\n

\u53c2\u8003\u6587\u732e\u3068\u6b21\u306e\u30b9\u30c6\u30c3\u30d7<\/h2>\n