{"product_id":"ac-4-pole-mcb-20a-32a-40a-63a","title":"AC 4 Pole MCB 20A, 32A, 40A, 63A","description":"\u003ch2\u003eCNC 4 Pole MCB — Three-Phase Plus Neutral Miniature Circuit Breaker\u003c\/h2\u003e\n\u003cp\u003eThe CNC YCB7-63N 4 pole MCB is a three-phase plus neutral (3P+N) miniature circuit breaker. It disconnects all four conductors — L1, L2, L3, and N — together in a single trip mechanism, giving complete isolation of a three-phase circuit. This is the standard choice for three-phase main incoming breakers in commercial, industrial, and large residential installations across Pakistan.\u003c\/p\u003e\n\u003cp\u003eUnlike the\u003cspan\u003e \u003c\/span\u003e\u003ca href=\"https:\/\/www.cncelectric.pk\/products\/cnc-3p-mcb-ac-circuits-breaker-ycb7h-63\"\u003e3 Pole MCB\u003c\/a\u003e\u003cspan\u003e \u003c\/span\u003ewhich only switches the three phases, the 4 Pole version also switches the neutral — essential for true isolation during maintenance, for three-phase solar inverter AC output, and for star-connected loads where the neutral carries unbalanced current. A fault on any phase trips all four poles simultaneously, preventing the dangerous single-phasing condition that destroys three-phase motors and compressors.\u003c\/p\u003e\n\u003cp\u003eRated at 400V AC with C-curve trip response and 6kA breaking capacity per IEC 60898-1, the YCB7-63N 4P handles three-phase DB feeders, motor circuits with neutral, 3-phase pump starters, and solar inverter AC output protection. CNC Electric is a trusted MCB brand in Pakistan with a\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e5-year replacement warranty\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eon all circuit breakers.\u003c\/p\u003e\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eProduct Type\u003c\/td\u003e\n\u003ctd\u003e4 Pole MCB — Three-phase + Neutral Miniature Circuit Breaker\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel\u003c\/td\u003e\n\u003ctd\u003eYCB7-63N (4P)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePoles\u003c\/td\u003e\n\u003ctd\u003e4P (L1 + L2 + L3 + N — all four switched together)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCurrent Ratings\u003c\/td\u003e\n\u003ctd\u003e20A, 32A, 40A, 63A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRated Voltage\u003c\/td\u003e\n\u003ctd\u003e400V AC, 50Hz (3-phase)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBreaking Capacity\u003c\/td\u003e\n\u003ctd\u003e6kA at 400V AC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTrip Curve\u003c\/td\u003e\n\u003ctd\u003eC-curve (trips at 5-10× rated current)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eStandard\u003c\/td\u003e\n\u003ctd\u003eIEC 60898-1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMounting\u003c\/td\u003e\n\u003ctd\u003e35mm DIN rail\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModule Width\u003c\/td\u003e\n\u003ctd\u003e4 modules (72mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTerminal Capacity\u003c\/td\u003e\n\u003ctd\u003eUp to 25mm² cable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMechanical Life\u003c\/td\u003e\n\u003ctd\u003e20,000 operations\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eElectrical Life\u003c\/td\u003e\n\u003ctd\u003e10,000 operations\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003e5-year replacement warranty\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch2\u003eWhy 4 Pole (3P+N) Over 3 Pole?\u003c\/h2\u003e\n\u003cp\u003eThe key difference between a 3 Pole and a 4 Pole MCB is whether the neutral is switched together with the phases. For Pakistani installations, the 4 Pole version is preferred in these situations:\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eThree-phase main incoming breaker.\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eWhen WAPDA supply arrives on four conductors (3 phases + neutral), the main breaker should disconnect all four during maintenance or fault. A 3 Pole leaves the neutral connected; a 4 Pole fully de-energises the DB. Safety personnel can service the downstream panel only after full isolation — that requires a 4 Pole.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eThree-phase solar inverter AC output.\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eHybrid and on-grid 3-phase solar inverters generate their own live-and-neutral AC output. When the inverter is off, the neutral from the inverter side must be isolated from the neutral from WAPDA to prevent parallel-path issues. A 4 Pole MCB on the inverter output ensures the inverter neutral is switched together with the three phases.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eStar-connected three-phase loads.\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eLoads wired in star configuration (heating elements, some motors, unbalanced lighting systems) use the neutral as a return path. The neutral can carry significant current under unbalanced conditions, so it must be switched with the phases during fault or maintenance.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eGenerator and ATS panels.\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eWhen WAPDA and generator supplies are alternated via an\u003cspan\u003e \u003c\/span\u003e\u003ca href=\"https:\/\/www.cncelectric.pk\/collections\/ats\"\u003eAutomatic Transfer Switch\u003c\/a\u003e\u003cspan\u003e \u003c\/span\u003eor manual\u003cspan\u003e \u003c\/span\u003e\u003ca href=\"https:\/\/www.cncelectric.pk\/collections\/changeovers\"\u003echangeover\u003c\/a\u003e, the neutral from each source is typically separate. The 4 Pole MCB on each source ensures the neutral of one source never conflicts with the neutral of the other.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eUse a 3 Pole instead\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eif the load has no neutral (delta-connected motors, pumps, compressors), or if the neutral is handled separately via a common busbar.\u003c\/p\u003e\n\u003ch2\u003e4P MCB — Amperage Selection Guide\u003c\/h2\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eRating\u003c\/th\u003e\n\u003cth\u003eCable Size\u003c\/th\u003e\n\u003cth\u003eTypical Application in Pakistan\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e20A\u003c\/td\u003e\n\u003ctd\u003e2.5mm²\u003c\/td\u003e\n\u003ctd\u003eSmall 3-phase sub-DB, 5 HP motor feeder\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e32A\u003c\/td\u003e\n\u003ctd\u003e6mm²\u003c\/td\u003e\n\u003ctd\u003e10 HP motor, 10 kW 3-phase solar inverter output, commercial sub-main\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e40A\u003c\/td\u003e\n\u003ctd\u003e10mm²\u003c\/td\u003e\n\u003ctd\u003e15 HP motor, 15 kW solar inverter output, medium commercial main\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e63A\u003c\/td\u003e\n\u003ctd\u003e16mm²\u003c\/td\u003e\n\u003ctd\u003e\n\u003cstrong\u003eThree-phase main incomer\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003efor shop\/office, 20-25 HP motor, 20 kW solar inverter\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003e\u003cstrong\u003eAbove 63A:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003emove to a\u003cspan\u003e \u003c\/span\u003e\u003ca href=\"https:\/\/www.cncelectric.pk\/collections\/ac-mccb-breakers\"\u003e4-Pole MCCB\u003c\/a\u003e\u003cspan\u003e \u003c\/span\u003erated 100A–1600A for larger commercial and industrial installations.\u003c\/p\u003e\n\u003ch2\u003eThree-Phase Motor Sizing with 4 Pole MCB\u003c\/h2\u003e\n\u003cp\u003eFor motor feeders, select the 4 Pole MCB at approximately 1.25× the motor full-load current on 400V 3-phase:\u003c\/p\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eMotor Size\u003c\/th\u003e\n\u003cth\u003eApprox FLC\u003c\/th\u003e\n\u003cth\u003e4P MCB\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e5 HP (3.7 kW)\u003c\/td\u003e\n\u003ctd\u003e~9A\u003c\/td\u003e\n\u003ctd\u003e20A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e10 HP (7.5 kW)\u003c\/td\u003e\n\u003ctd\u003e~18A\u003c\/td\u003e\n\u003ctd\u003e32A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e15 HP (11 kW)\u003c\/td\u003e\n\u003ctd\u003e~27A\u003c\/td\u003e\n\u003ctd\u003e40A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e20 HP (15 kW)\u003c\/td\u003e\n\u003ctd\u003e~37A\u003c\/td\u003e\n\u003ctd\u003e63A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAbove 20 HP\u003c\/td\u003e\n\u003ctd\u003eOver 37A\u003c\/td\u003e\n\u003ctd\u003e\u003ca href=\"https:\/\/www.cncelectric.pk\/collections\/ac-mccb-breakers\"\u003e4P MCCB 100A+\u003c\/a\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003eFor motors with heavy starting inrush (star-delta starter, DOL on 15 HP+), consider a D-curve MCB variant or pair this C-curve with a dedicated motor-protection relay. For 3-phase solar inverter AC output, size the MCB at approximately 1.25× the inverter rated AC output current.\u003c\/p\u003e\n\u003ch2\u003eTypical Applications\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003e3-phase main incoming breaker.\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eCommercial shops, offices, small factories, large homes with 3-phase WAPDA supply. The 63A 4P sits at the top of the DB — all power flows through it first. Install a\u003cspan\u003e \u003c\/span\u003e\u003ca href=\"https:\/\/www.cncelectric.pk\/collections\/phase-sequence-relay\"\u003ephase sequence relay\u003c\/a\u003e\u003cspan\u003e \u003c\/span\u003eimmediately after for phase-reversal protection.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e3-phase solar inverter AC output.\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eOn-grid and hybrid 3-phase solar inverters up to 22 kW. The 4P on the inverter output ensures the inverter (its live and neutral) can be completely isolated from the house DB during maintenance. For 25 kW+, use a 4P MCCB.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e3-phase motor feeder with neutral.\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eStar-connected 3-phase motors and loads (unbalanced lighting, heating elements, some HVAC systems) where the neutral carries actual current.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eGenerator 4-wire changeover panel.\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eWhen the generator and WAPDA each provide their own neutral, the 4P MCB on each source ensures proper isolation during\u003cspan\u003e \u003c\/span\u003e\u003ca href=\"https:\/\/www.cncelectric.pk\/collections\/ats\"\u003eATS\u003c\/a\u003e\u003cspan\u003e \u003c\/span\u003eor manual switching.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eAgricultural tube-well panels.\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eSubmersible pumps with 3-phase star-connected motors, especially when the panel is remote and requires full isolation for safe servicing.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCommercial kitchen panels.\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e3-phase sub-DBs feeding ovens, heaters, chillers — often unbalanced loads with significant neutral current.\u003c\/p\u003e\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eWire the neutral through the 4th pole.\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eConnect L1 to pole 1, L2 to pole 2, L3 to pole 3, and neutral to pole 4. All four poles trip together on a fault anywhere in the circuit.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eUse 6mm² copper for 32A and below; 10mm² for 40A; 16mm² for 63A.\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eSize the neutral conductor the same as the phase conductors (not reduced) for unbalanced loads.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eTorque terminal screws to 2.5 Nm.\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eRe-check tightness after 3 months of service. At 63A continuous, a loose terminal overheats and is a major cause of panel failures in Pakistan.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003ePlan DB space:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003ethis 4 Pole MCB is 72mm wide (4 modules). An 18-way DB with one 4P main incomer uses 4 modules, leaving 14 for branch circuits.\u003c\/p\u003e\n\u003ch2\u003eRelated Products\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eThree-phase without neutral →\u003cspan\u003e \u003c\/span\u003e\u003ca href=\"https:\/\/www.cncelectric.pk\/products\/cnc-3p-mcb-ac-circuits-breaker-ycb7h-63\"\u003e3 Pole MCB 16A-63A (Rs.1,350)\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003eSingle-phase branch circuits →\u003cspan\u003e \u003c\/span\u003e\u003ca href=\"https:\/\/www.cncelectric.pk\/products\/cnc-1-pole-mcb-ac-breaker-ycb7-63a\"\u003e1 Pole MCB 2A-63A (Rs.425)\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003eSingle-phase main incomer →\u003cspan\u003e \u003c\/span\u003e\u003ca href=\"https:\/\/www.cncelectric.pk\/products\/cnc-2p-mcb-ac-circuit-breaker-500v-ycb7h-63\"\u003e2 Pole MCB 10A-63A (Rs.850)\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003eAbove 63A or industrial fault levels →\u003cspan\u003e \u003c\/span\u003e\u003ca href=\"https:\/\/www.cncelectric.pk\/collections\/ac-mccb-breakers\"\u003eMCCB 4P 100A-1600A\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003e3-phase generator auto-switching →\u003cspan\u003e \u003c\/span\u003e\u003ca href=\"https:\/\/www.cncelectric.pk\/collections\/ats\"\u003eATS 4-pole\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003e3-phase manual changeover →\u003cspan\u003e \u003c\/span\u003e\u003ca href=\"https:\/\/www.cncelectric.pk\/collections\/changeovers\"\u003eChangeover switches 4P\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003ePhase-sequence \/ reversal protection →\u003cspan\u003e \u003c\/span\u003e\u003ca href=\"https:\/\/www.cncelectric.pk\/collections\/phase-sequence-relay\"\u003ePhase Sequence Relay\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003e3-phase voltage protection →\u003cspan\u003e \u003c\/span\u003e\u003ca href=\"https:\/\/www.cncelectric.pk\/pages\/voltage-protector-finder\"\u003eVA Voltage Protector\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003eMotor contactor for start\/stop →\u003cspan\u003e \u003c\/span\u003e\u003ca href=\"https:\/\/www.cncelectric.pk\/collections\/magnetic-contactors\"\u003eMagnetic contactors\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003e3-phase SPD \/ surge protection →\u003cspan\u003e \u003c\/span\u003e\u003ca href=\"https:\/\/www.cncelectric.pk\/collections\/spd\"\u003eSPD 4-pole\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003eComplete 3-phase DB →\u003cspan\u003e \u003c\/span\u003e\u003ca href=\"https:\/\/www.cncelectric.pk\/collections\/db-boxes\"\u003eDB boxes\u003c\/a\u003e\u003cspan\u003e \u003c\/span\u003e+ breakers\u003c\/li\u003e\n\u003cli\u003eRead our guide →\u003cspan\u003e \u003c\/span\u003e\u003ca href=\"https:\/\/www.cncelectric.pk\/blogs\/guides\/types-of-circuit-breakers\"\u003eTypes of Circuit Breakers in Pakistan\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003ch3\u003eWhat is a 4 Pole MCB?\u003c\/h3\u003e\n\u003cp\u003eA 4 Pole MCB is a miniature circuit breaker that protects a three-phase plus neutral (3P+N) circuit by disconnecting all four conductors — L1, L2, L3, and neutral — together on overload or short circuit. The four poles are mechanically linked so a fault on any phase or on the neutral trips all four. This gives complete isolation of the three-phase circuit, essential for main incomers and star-connected loads.\u003c\/p\u003e\n\u003ch3\u003eWhat is the difference between 3 Pole and 4 Pole MCB?\u003c\/h3\u003e\n\u003cp\u003eA 3 Pole MCB switches only the three phase conductors. A 4 Pole MCB switches all three phases plus the neutral. Use 3P for circuits without neutral (delta-connected motors) or where the neutral is handled by a separate busbar. Use 4P for three-phase main incomers, solar inverter 3-phase outputs, star-connected loads, and generator changeover panels that need complete isolation.\u003c\/p\u003e\n\u003ch3\u003eWhat size 4 Pole MCB for a three-phase main incomer?\u003c\/h3\u003e\n\u003cp\u003eFor a typical 3-phase commercial or residential main incomer in Pakistan, use a\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e63A 4 Pole MCB\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003ewith 16mm² copper cable. This handles roughly 20-25 HP total load. For larger loads, move to a\u003cspan\u003e \u003c\/span\u003e\u003ca href=\"https:\/\/www.cncelectric.pk\/collections\/ac-mccb-breakers\"\u003e4 Pole MCCB\u003c\/a\u003e\u003cspan\u003e \u003c\/span\u003erated 100A or higher. Pair the main 4P with a phase sequence relay for phase-reversal protection.\u003c\/p\u003e\n\u003ch3\u003eWhat is the 4 Pole 63A MCB price in Pakistan?\u003c\/h3\u003e\n\u003cp\u003eThe CNC YCB7-63N 4 Pole 63A MCB is available at Rs.1,900 at CNC Electric Pakistan. Competitor brands: Schneider iC60N 4P 63A typically costs Rs.7,500-10,000, and Chint NB1 4P 63A costs Rs.2,800-3,500. CNC offers equivalent IEC 60898-1 certified performance at a significantly lower price with a 5-year replacement warranty.\u003c\/p\u003e\n\u003ch3\u003eCan I use a 4 Pole MCB for my 3-phase solar inverter?\u003c\/h3\u003e\n\u003cp\u003eYes — for the AC output side of a 3-phase solar inverter, a 4 Pole MCB is the correct choice. It ensures the inverter's live and neutral are fully isolated from the house DB during maintenance. Size it at approximately 1.25× the inverter's rated AC output current. For the DC side (panels to inverter), never use an AC MCB — use\u003cspan\u003e \u003c\/span\u003e\u003ca href=\"https:\/\/www.cncelectric.pk\/collections\/dc-breaker\"\u003eDC circuit breakers\u003c\/a\u003e\u003cspan\u003e \u003c\/span\u003erated for your system voltage (500V, 1000V, or 1500V).\u003c\/p\u003e\n\u003ch3\u003eDoes the 4 Pole MCB provide motor overload protection?\u003c\/h3\u003e\n\u003cp\u003ePartially. The 4 Pole MCB protects the cable and panel against short circuit and trips on sustained overload. It does NOT detect motor-specific issues like stalled rotor, unbalanced phases, or phase reversal. For complete three-phase motor protection, combine this 4P MCB with (a) a thermal overload relay set to the motor FLC, (b) a phase sequence relay, and\/or (c) a motor-protection circuit breaker (MPCB) or VFD with built-in motor protection.\u003c\/p\u003e\n\u003ch3\u003eWhat breaking capacity does the CNC 4 Pole MCB have?\u003c\/h3\u003e\n\u003cp\u003e6kA at 400V AC per IEC 60898-1. This is adequate for residential, commercial, and small industrial 3-phase panels where the prospective short-circuit current is under 6 kA. For installations close to a large transformer where fault levels exceed 6 kA, move up to a 4P\u003cspan\u003e \u003c\/span\u003e\u003ca href=\"https:\/\/www.cncelectric.pk\/collections\/ac-mccb-breakers\"\u003eMCCB\u003c\/a\u003e\u003cspan\u003e \u003c\/span\u003ewith 15-50 kA breaking capacity.\u003c\/p\u003e\n\u003ch3\u003eHow wide is the 4 Pole MCB on the DIN rail?\u003c\/h3\u003e\n\u003cp\u003eThe CNC YCB7-63N 4 Pole MCB is 72mm wide — four DIN-rail modules. Plan your DB box capacity accordingly: an 18-way DB with one 4P main incomer uses 4 modules, leaving 14 modules for branch circuits (single pole or 1P+N MCBs).\u003c\/p\u003e","brand":"Solarleaf.pk","offers":[{"title":"Default Title","offer_id":53465450053997,"sku":null,"price":0.0,"currency_code":"PKR","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1007\/8280\/1261\/files\/Screenshot2026-06-18224201.png?v=1781804624","url":"https:\/\/solarleaf.pk\/products\/ac-4-pole-mcb-20a-32a-40a-63a","provider":"Solarleaf.pk","version":"1.0","type":"link"}