Mitsubishi NV125-SV 3P 63A Earth Leakage Circuit Breaker

NV = Earth Leakage Circuit Breaker (BELCB); NF = standard MCCB without earth leakage protection; 125 = Frame size AF125A; SV = Standard S model; 3P = 3-pole; 63A = rated operational current In=63A

✅ Core Electrical Specifications

Articolo	Parametro
Modello completo n.	NV125‑SV 3P 63A with adjustable earth leakage 100/200/500mA
Rated Voltage Ue	AC100~440V, suitable for 3-phase 3-wire / single-phase 2-wire circuits
Corrente nominale in	63UN
Poli	3P (3 fasi, neutral not switched)
Short-circuit Breaking Capacity Icu/Ics@AC400V	30IL / 30IL
Earth Leakage Sensitivity	3-level adjustable: 100mA / 200mA / 500mA
Tipo di perdita	Tipo CA, surge resistant, anti-harmonic, suppresses nuisance tripping
Tempo di funzionamento	Massimo. 0.04S
Dimensione complessiva (L×A×P)	90mm × 130mm × 90mm
Peso	ca. 1.1kg

📌 Model Code Breakdown

NV: Earth Leakage Circuit Breaker (BELCB, moulded case type with leakage protection)
125: Frame rating 125A (dimensione del telaio, this unit rated 63A)
SV: Tipo S standard (New WS-V generation); CV = Economy type, HV = High breaking capacity type
3P: 3-palo, protects 3 live phases, neutral line does not pass through breaker
63UN: Continuous rated circuit current 63A

Common suffix: 1.2.500MA = 100/200/500mA adjustable earth leakage

🛠️ Application Scenarios

Industrial control panels, pompe dell'acqua, tifosi, small 3-phase power circuits

Integrated protection for equipment: dispersione verso terra, sovraccarico & protezione da cortocircuito

Suitable for harmonic-rich environments (VFD, servoazionamenti), less prone to nuisance tripping than older generations

Montaggio a pannello, standard screw terminals; accessori opzionali: Alarm switch AL, Auxiliary switch AX, Viaggio di derivazione / Under-voltage coil

⚠️ Selection & Note di sostituzione

Distinguish NV (ELCB with leakage) vs NF (standard MCCB without leakage). Similar appearance, NON direttamente intercambiabili.
3P version does NOT disconnect neutral conductor. Select 4P model NV125-SV 4P if neutral switching is required.
Earth leakage threshold is preset at factory and adjustable via rotary knob on site; 100mA per la protezione personale, 200/500mA for equipment fire protection.
Domestic alternatives reference: CHNT NM1LE-125S/3P 63A, Delixi CDM1LE-125/3P 63A; verify breaking capacity and adjustable leakage range.
Within the same frame size, current rating can be changed directly (63/75/80/100/125UN), mounting dimensions remain unchanged.

🧰 Troubleshooting Quick Reference

Trips immediately upon closing: Priority check for earth leakage or damaged load insulation; try higher leakage threshold.

Intervento per sovraccarico: Continuous load current >63UN; inspect motor / cable loading.

Short-circuit tripping: Severe short circuit; power off and inspect for phase-to-phase short circuit.

Leakage protection fails to operate: Press red TEST button periodically; verify leakage function monthly.

Mitsubishi NV125-SV (WS-V Series) Built-in Accessory List (ASCIA / AL / SHT / UVT)

All accessories are clip-on built-in modules, field mountable; compatible for NV125-SV / NF125-SV same frame; accessories installed in the right-side compartment of breaker.

AX Auxiliary Switch

Modello: ASCIA-03SVU

Funzione: Reports ON/OFF status of main contacts, cannot distinguish manual opening or fault tripping

Valutazione dei contatti: 1a1b (1NO +1NC)

Applicazione: Send breaker position signal to PLC / spie luminose

Cablaggio: Lead wire type; SLT version available with terminal block

AL Alarm Switch

Modello: AL-03SVU

Funzione: Activates ONLY when tripped by fault (sovraccarico, cortocircuito, dispersione verso terra); no action during manual opening

Valutazione dei contatti: 1a1b

Applicazione: Fault trip alarm, SCADA signal upload, udibile & allarme visivo

Combined module: ALAX-03SVU = integrated AX+AL module (provides both position feedback and fault trip signal, più ampiamente utilizzato)

SHT Shunt Trip

Voltage variants:

SHTA240-03SVU: AC100～240V AC shunt trip

SHTA440-03SVU: AC200～440V AC shunt trip

SHTD100-03SVU: DC24V DC shunt trip

Suffix U: built-in module; L = extended lead; S = special spec

Funzione: Remote electrical trip via control signal; used for emergency stop, fire linkage circuit cut-off

Nota importante: Short-time energized type, continuous power supply is prohibited.

UVT Under Voltage Trip

Two types:

UVTN-03SVU Non-synchronous UVT: Instant trip upon voltage drop

UVTS-03SVU Synchronous UVT: Trip at voltage zero-crossing during voltage drop, for large inductive loads to reduce breaking surge

Voltage ratings: AC100/200/240/400V optional

Funzione: Automatic trip when main circuit voltage drops or power loss; will NOT auto-reclose after voltage recovery, manual closing required on site.

External Accessories for NV125-SV

Modello accessorio	Nome	Descrizione
TC‑1SV	Copertura terminale	Insulation protection for exposed terminals
LC‑1SV	Padlock device	Handle lockout, prevent accidental closing
MI‑05SV3	Interblocco meccanico	Mechanical interlock for 2 interruttori automatici (dual power switching)
HLF‑1SV	External rotary handle	Panel mounted operating handle, with door interlock

⚠️ Selection & Limitazioni all'installazione (Critico)

One NV125-SV breaker can be fitted with max. one built-in accessory module only. SHT + ALAX cannot be installed together.

Opzione A: ALAX (posizione + fault signal)

Opzione B: SHT (intervento remoto)

Option C: UVT (under-voltage protection)

Built-in accessories occupy space on the right side of breaker. Do not mount breakers side-by-side with zero clearance when fitted with internal accessories (UVT needs extra space).
Two ordering options:

Breaker pre-fitted with accessories at factory (complete unit order)

Purchase accessory modules separately and assemble on site

ELCB NV125-SV supports SHT/UVT installation for fire linkage and loss-of-voltage protection; accessories are interchangeable with NF125-SV standard MCCB.

Ordering Examples

NV125-SV 3P 63A + ALAX-03SVU (with switch position & fault alarm contacts)

NV125-SV 3P 63A + SHTA240-03SVU (AC220V remote shunt trip)

Full Model List of Mitsubishi NV125-SV (WS-V ELCB)

Frame AF125, Icu=30kA / Ics=30kA @AC400V; Standard AC type leakage 100/200/500mA adjustable; 3P /4P; viaggio magnetotermico; dimension W90×H130×D90mm

Naming format: NV125-SV [3P/4P] [Rated Current A]

✅ Rated Current Range (In)

16UN, 20UN, 25UN, 32UN, 40UN, 50UN, 63UN, 75UN, 80UN, 100UN, 125UN

✅ Full Model Matrix

3P (3-fase, neutral not switched)

NV125-SV 3P 16A

NV125-SV 3P 20A

NV125-SV 3P 25A

NV125-SV 3P 32A

NV125-SV 3P 40A

NV125-SV 3P 50A

NV125-SV 3P 63A (target model)

NV125-SV 3P 75A

NV125-SV 3P 80A

NV125-SV 3P 100A

NV125-SV 3P 125A

4P (3-fase + polo neutro, neutral can be disconnected)

NV125-SV 4P 16A

NV125-SV 4P 20A

NV125-SV 4P 25A

NV125-SV 4P 32A

NV125-SV 4P 40A

NV125-SV 4P 50A

NV125-SV 4P 63A

NV125-SV 4P 75A

NV125-SV 4P 80A

NV125-SV 4P 100A

NV125-SV 4P 125A

Derived variants on same WS-V platform

NV125-CV: Versione economica, Icu=10kA @AC400V

NV125-HV: Elevato potere di interruzione, Icu=50kA @AC400V

NV125-SEV/HEV: Electronic trip ELCB (electronic protection, long/short time delay available)

Suffix explanation: 1.2.500MA = 100/200/500mA adjustable leakage (standard for China market); 30mA high-speed leakage variant available for personal protection.

Cross-brand Equivalent Reference (Reference target: NV125-SV 3P 63A, AC400V, Icu≥30kA, adjustable leakage 100/200/500mA, magnetotermico)

⚠️ Important note: Physical size and accessories are NOT interchangeable; only electrical equivalent. Verify cabinet cutout, wiring and accessory interface for site retrofit. Table based on 63A/3P.

Marca	Modello equivalente	Parametri chiave	Osservazioni
Mitsubishi Original	NV125-SV 3P 63A	3P63A, Icu=30kA@400V, AC leakage 100/200/500mA adjustable, viaggio magnetotermico	Reference unit, WS-V series
Schneider	EZD125E 3P 63A Vigi (modulo perdite)	3P63A, Icu=30kA, adjustable residual current	EZD125E + separate Vigi module; split type leakage, not integrated ELCB; different dimension
Schneider	NSX100N 3P 63A Vigi	Icu=36kA, adjustable leakage	NSX higher performance, prezzo più alto, modular leakage
ABB	T2N160 3P 63A RCD	Icu=36kA, adjustable AC residual current	MCCB body + external RCD module, integrated solution Tmax T2N
Siemens	3VT8106-1AA03-0AA0 + leakage trip module	3P63A, Icu=25kA, optional leakage module	Breaking capacity slightly lower than Mitsubishi; check short-circuit capacity
CHNT	NM1LE-125S/3P 63A	3P63A, Icu=35kA, leakage 100/200/500mA adjustable	Main domestic alternative, integrated ELCB, magnetotermico, similar mounting size
Delizioso	CDM1LE-125/3P 63A	3P63A, Icu=35kA, multi-level adjustable leakage	Alternativa domestica, 125AF frame, integrated leakage
Persone elettriche	RMM1LE-125/3P 63A	3P63A, Icu=35kA, adjustable leakage	Alternativa domestica economica

Key Differences for Replacement Engineering

Leakage construction: Mitsubishi NV125-SV is integrated built-in leakage. Schneider NSX/EZD and ABB Tmax mostly adopt separate external leakage modules, more failure points.
Potere di interruzione: NV125-SV Icu=30kA; Icu cannot be downgraded during replacement, risk of breaker failure under bus short-circuit.
Compatibilità accessori: Mitsubishi AX/AL/SHT/UVT are right-side clip-on modules; Schneider/ABB accessories are independent modules. Mitsubishi old accessories cannot be reused, new accessories must be purchased for retrofit.
Selezione del palo: 3P only switches 3 live conductors, neutral passes through. Select 4P if neutral protection is required.
Leakage type: Above are all AC type, suitable for standard power frequency loads. For VFD-heavy systems, A/F type leakage is recommended.

Mitsubishi Legacy to WS-V Upgrade

Old NV125-SW / NV125-SVL (old WS series) → NV125-SV (WS-V)

Same outer dimension, mounting hole compatible

Higher short-circuit breaking capacity (old 25kA upgraded to 30kA)

Updated accessory model: old SW accessories incompatible with SV; must use -03SVU series (ASCIA-03SVU / AL-03SVU)

Recommended Replacement Priority

Cabinet space & accessory reuse preferred: Original Mitsubishi NV125-SV
Import equivalent upgrade: ABB T2N160 / Schneider NSX100N Vigi
Cost-effective domestic engineering replacement: CHNT NM1LE-125S / Delixi CDM1LE-125

NV125-SV 3P 63A Replacement Retrofit Risk Checklist

Ambito: Replace Mitsubishi NV125-SV 3P 63A (BELCB, AC400V, Icu=30kA, 100/200/500mA adjustable leakage) with identical model, imported equivalent (ABB/Schneider/Siemens) or domestic alternative (CHNT/Delixi/People). Used for ECN, technical briefing, incoming inspection and pre-commissioning check. ✅=Pass; ❌=Fail; ⚠️=Requires confirmation/rectification

Electrical Parameter Verification (Highest Priority, No Icu Downgrade)

NO.	Controlla l'articolo	Requisito / Criterio
1	Corrente nominale in	New device ≥ 63A and matches circuit design; continuous load ≤0.8×In
2	Pole Consistency	Original 3P must use 3P; if changing to 4P for neutral switching, rework wiring & cabinet cutout
3	Rated Voltage Ue	New device rated voltage ≥ AC400V, compatible with system voltage
4	Short-circuit Breaking Icu@AC400V	New Icu ≥ 30kA (must not be lower than original NV125-SV 30kA), risk of breaker damage under bus short-circuit
5	IC (Potere di interruzione del servizio)	≥30kA, same as Icu, allows reclose after short-circuit event
6	Earth Leakage Protection Type	Tipo CA (or A/F type); adjustable leakage range 100/200/500mA must be retained
7	Leakage Operating Time	≤0,04 s (ad alta velocità); separately verify for 30mA personal protection version
8	Thermal-Magnetic Trip Characteristic	Sovraccarico / short-circuit trip curve must match original coordination; electronic trip requires setting verification
9	Short-circuit Selectivity	Recheck selectivity coordination with upstream and downstream protective devices

⚠️ Red Line Rule①: Do NOT energize any replacement unit with Icu <30IL. Leave panel de-energized rather than downgrade breaking capacity.

Installazione meccanica & Dimension Check

NO.	Controlla l'articolo	Requisito / Criterio
1	Ritaglio di montaggio	Compare original NV125-SV (W90×H130×D90mm) with cabinet cutout; re-cut or use adapter plate if dimension mismatch
2	Tipo di montaggio	TH35 DIN rail or panel bolt mounting compatible with original bracket
3	Spazio di cablaggio	In/out terminal clearance sufficient for cable stripping and crimping (meet minimum cable bending radius)
4	Phase Clearance	Creepage & air clearance between phase terminals comply with new device specification
5	Dissipazione del calore	Panel spacing meets thermal requirement; no tight side-by-side mounting with internal accessories fitted (UVT especially)
6	Maniglia / Door Cutout	Door opening and handle projection match new device; confirm if external rotary handle needs replacement
7	Torque for Terminals	Tightening torque follows manufacturer manual; conductor cross-section adequate, crimping secure

⚠️ Red Line Rule②: Do not force oversized cutout or suspend breaker without proper support. Use manufacturer drawing or adapter plate.

Accessory Compatibility Check (High Risk, Frequently Missed)

NO.	Controlla l'articolo	Requisito / Criterio
1	Accessory Interface	Original AX-03SVU / AL-03SVU / SHTA/D / UVTN/S cannot be fitted to other brands; purchase new accessories matching new breaker brand
2	Allarme / Position Signal	Re-select equivalent ALAX accessory for new breaker and rewire secondary circuit
3	Shunt Trip SHT	Reconfigure remote trip, verify AC/DC voltage rating
4	Under Voltage Trip UVT	Reconfigure UVT; verify trip characteristic (sincrono / non-synchronous) against load type
5	Mechanical Interlock MI	Dual power interlock must be matched accessory from new brand; interlocks from different brands are incompatible
6	Terminal Cover / Lockout	Fit TC/LC protective accessories as per new device spec
7	External Leakage Module (Import Split Type)	Schneider NSX/EZD, ABB T2N use separate leakage module; confirm module installed and wired correctly

⚠️ Red Line Rule③: Do NOT reuse old Mitsubishi accessories on new breakers. Mismatched assembly causes poor contact, loss of alarm or protection function.

Principale & Secondary Wiring Check

NO.	Controlla l'articolo	Requisito / Criterio
1	Cablaggio del circuito principale	Phase sequence matches busbar, terminals fully tightened
2	Neutral Handling	3P version neutral passes through unswitched; rewire neutral if replaced with 4P
3	Zero-sequence CT / Leakage Transformer	Integrated ELCB has built-in CT, no external CT needed; check CT cable passing direction for split leakage module
4	Secondary Control Wires	AX/AL contacts to PLC / indicator circuit; verify contact type (1a1b) and voltage rating
5	Shunt / UVT Coil Wiring	SHT is short-time energized, continuous power forbidden; UVT coil voltage matches supply
6	Wiring Marking	Phase labels and accessory terminal numbers clear and consistent with drawing
7	Coppia terminale	Follow manufacturer torque specification to avoid overheating / connessione allentata

⚠️ Red Line Rule④: SHT coil is short-time energized, continuous supply burns coil. UVT will not auto-close after voltage recovery; manual closing required in commissioning procedure.

Pre-commissioning Test & Acceptance

NO.	Controlla l'articolo	Requisito / Criterio
1	Prova di isolamento	Phase-to-phase / phase-earth insulation resistance meets requirement; disconnect secondary / electronic accessories before test
2	Prova di perdita (TEST Button)	Press red TEST button; breaker must trip reliably to validate leakage protection
3	Leakage Threshold Verification	Test tripping at 100/200/500mA if site conditions permit
4	Sovraccarico / Short-circuit Simulation	Verify thermal-magnetic trip if test available; otherwise confirm factory trip characteristic
5	Accessory Function Test	Test ALAX alarm contact, SHT remote trip, UVT under-voltage trip one by one
6	Mechanical Operation	ON/OFF manuale regolare, no jamming, no missing phase
7	Senza carico & Load Trial Run	Close breaker under no-load first; then energize load, monitor temperature and nuisance tripping
8	Earthing Continuity	Equipment and cabinet protective earth secure
9	Setting Record Filing	Document new breaker rating, leakage setting and accessory configuration

⚠️ Red Line Rule⑤: Do NOT put into formal operation before passing TEST button leakage verification. ELCB without working leakage protection functions only as ordinary MCCB, no personnel protection.

Inapplicable Conditions & Operazioni proibite

Scenario / Operazione	Sentenza
Frequent ON/OFF cycling	⚠️ Thermal-magnetic trip not suitable for high cycle rate; use motor protector or add contactor
Heavy corrosion, polvere, condensazione	❌ Standard model not suitable; IP rated enclosure + anti-condensation heater required
VFD & servo heavy harmonic environment	⚠️ AC type may nuisance trip; upgrade to A/F type leakage or surge-resistant model
Replace breaker with upstream live	❌ Live working prohibited. Spegnimento, test dead, lockout-tagout (CUORE) necessario
Reset immediately after leakage trip without investigation	❌ Do not repeatedly reclose; troubleshoot insulation/earth fault first
Replace ELCB with standard MCCB (NF)	❌ Loss of earth leakage protection, severamente proibito
Replace with lower Icu rating	❌ Not allowed