(Codice articolo standard: FWP-25A22F. The suffix FA is a trade designation; AMP25 means 25A and is not part of the original Eaton model number.)
Tipo di prodotto: aR IEC cylindrical high-speed semiconductor fusibile (ceramic tube, ferrule terminals), 22×58mm size
Spiegazione del codice modello
FWP: Bussmann IEC high-speed semiconductor fuse series
25: Corrente nominale 25A
UN: aR (semiconductor protection, solo protezione da cortocircuito; not suitable for sustained overload)
22: Size code for 22×58mm
F: No striker / no fuse indication (FI = with striker, can actuate microswitch)
FA: Mercato / customs alias; official part number is FWP-25A22F
AMP25: Simple current marking of 25A, not part of original model
Specifiche elettriche principali
Tensione nominale: 700V e / 700A DC (IEC/UL)
Corrente nominale: 25UN
Capacità di interruzione: AC 200kA (symmetrical rms); DC 50kA @700Vdc
Fuse Class: aR (semiconductor short-circuit protection)
Pre-arcing I²t: 37; Total clearing I²t @700VAC: 530
Rated Power Dissipation: 6W
Fattore di forma: 22×58mm, ceramic tube, copper ferrules at both ends
Peso netto: ca. 62.6G
Certificazioni & Conformità
UL Recognized JFHR2, CSA, CE, RoHS
Compatible Fuse Holder: JM70100 (matching safety fuse base)
Applicazioni tipiche
Short-circuit protection for DC busbars, DC drives, convertitori di frequenza, rectifiers / convertitori di potenza, SCR and IGBT semiconductor devices. Widely used in PV energy storage, servo power supplies and UPS DC sides.
Nota: aR provides short-circuit protection only and cannot replace gR overload protection.
Confronto con modelli simili
FWP-25A22F: No striker (questo modello)
FWP-25A22FI: With striker, triggers microswitch for alarm upon melting
FWP-25G22F: gR class (sovraccarico + protezione da cortocircuito), 600Versione V
FWP-25A22F / FWP-25A22FI (22×58mm FWP aR Cylindrical High-Speed Fuse)
Modelli applicabili: FWP-25A22F (no striker) / FWP-25A22FI (with striker)
Basic Electrical Table
| Parametro | FWP-25A22F | FWP-25A22FI |
| Definizione del suffisso | F = No striker | FI = F + IO, fitted with striker |
| Classe di protezione | aR (semiconductor short-circuit protection, nessuna protezione da sovraccarico) | aR |
| Rated AC Voltage | 700V IEC | 700V IEC |
| Rated DC Voltage | 700A DC | 500A DC (critical difference!) |
| Corrente nominale in | 25UN | 25UN |
| AC Breaking Capacity | 200kA rms symmetrical | 200kA rms symmetrical |
| DC Breaking Capacity | 50kA @700Vdc | 50kA @500Vdc |
| Pre-arcing I²t | 37 A²·s | 37 A²·s |
| Total clearing I²t (700V e, pf=0.15) | 530 A²·s | 530 A²·s |
| Power Dissipation @In | 6W | 6W |
| Dimensioni | 22×58mm ceramic ferrule fuse | 22×58mm ceramic ferrule fuse |
| Peso | 62.6G | 61.6G |
| Fuse Holder | JM70100 (compatible with microswitch version) | JM70100 (microswitch version required) |
| Certificazioni | Riconosciuto UL, CSA, CE, RoHS | Riconosciuto UL, CE, RoHS |
| Striker Function | No fuse alarm output | Striker pops on melting, actuates microswitch for dry contact alarm |
Promemoria importante: The FI model is derated to 500V DC. Do not use FI for DC bus >500V; use F version only. For AC operation, both versions have identical characteristics, I²t and time-current curves.
Time-Current (T-C) Characteristic Notes (Datasheet 720026)
Curves shown are nominal melt curves for aR fuses:
- Almost no operation under low-magnitude overload: aR is designed exclusively for semiconductor short-circuit protection, not conventional overload protection. Melting time is extremely long at 1.6×In (40UN), so it cannot be relied on for overload protection.
- Short-circuit region (ca. 10×In): Fast current-limiting melting with low I²t to protect IGBT/SCR. This is its intended operating range.
- Reference melt points (shared by FWP-25A22F / FI):
100UN: Melting time ~10ms
250UN: Melting time ~1ms
>500UN: Sub-millisecond current-limiting operation
Curve feature: The T-C curve of aR fuse is very steep. It operates extremely fast under large short-circuit current while tolerating low multiple overloads for a long time.
The original T-C diagram is log-log plotted. F and FI of the same current rating share identical melt curves; differences are limited to DC voltage rating and striker construction.
I²t Correction Rule (Mandatory for Semiconductor I²t Coordination Check)
IL 530 A²·s value above is total clearing I²t under 700V AC, fattore di potenza 0.15.
When operating voltage is lower than 700V AC, actual total clearing I²t reduces, multiplied by correction factor K:
Eg=700Vac → K=1.0
Eg=600Vac → K≈0.82
Eg=480Vac → K≈0.64
DC I²t verification cannot directly reuse AC I²t values. Separate DC curve check is required, especially for FI limited to 500Vdc.
Striker FI Wiring & Fuse Holder Description
JM70100 has two configurations:
- Standard JM70100: For F version only, no microswitch
- JM70100 + microswitch module: For FI version. Striker triggers microswitch, typically 1NO+1NC for PLC alarm or trip interlock.
⚠️ The striker provides only a mechanical alarm signal. It does not change fuse protection characteristics or increase breaking capacity.
FWP-25A22F vs FWP-25A22FI Application Selection Table
| Scenario applicativo | Modello consigliato | Motivo |
| DC bus 550~700V (accumulo di energia, PV DC side) | FWP-25A22F | FI limited to 500V DC, not permitted above |
| AC 690V frequency converter / rectifier, alarm required | FWP-25A22FI | Same AC parameters + funzione di allarme |
| AC application, no fault signal required, sensibile ai costi | FWP-25A22F | Costo inferiore, simpler construction |
| DC ≤500V with fuse trip reporting | FWP-25A22FI | Meets DC voltage and alarm requirement |
Coordination & Linee guida per la sostituzione (Engineering Reference)
- Semiconductor protection check sequence: Device withstand I²t ≥ fuse corrected total clearing I²t
- Do not replace with gG general-purpose fuses; gG has much higher I²t and may destroy IGBTs.
- Domestic replacement must satisfy three criteria: 22×58mm size, aR class, 700Vdc rating (if DC circuit), and I²t close to 530. Many domestic aR fuses are only rated 500Vdc and cannot directly substitute F version.
- Temperature derating: 25A rating is based on 25℃ ambient temperature. Derate to 0.85In typically for 40℃ cabinet ambient.
FWP-25A22FA (FWP-25A22F, aR 700VAC/700VDC, 25UN) Ambito di applicazione
Posizionamento centrale: aR high-speed semiconductor short-circuit fuse, low I²t current-limiting protection for IGBT, SCR, diode power devices, nessuna protezione da sovraccarico.
- Original Datasheet Listed Applications
- DC Common Bus
Shared DC bus for multi-drive systems, busbar short-circuit protection. Widely used in energy storage, multi-servo and multi-inverter common-bus schemes. 700Vdc rating supports high-voltage DC bus.
- DC Drives
DC motor drives, high-power DC speed controllers, short-circuit protection for rectifier bridges and SCR thyristors.
- Power Converters / Rectifiers
AC-DC rectifier modules, SCR rectifier cabinets, active / passive rectifier units.
- Reduced Voltage Solid-State Starters
Thyristor circuit short-circuit protection inside solid-state soft starters.
- Extended Industry Applications
PV & Stoccaggio dell'energia
PV inverter DC side, string inverter power loops
PCS DC bus, post battery cluster power circuit protection (≤700Vdc)
Vantaggio: 700Vdc rating, strong DC breaking capacity, low I²t, ideal for DC side.
Variable Frequency & Servoazionamenti
690V class three-phase inverter rectifier and IGBT module protection
High-power servo drives, multi-axis servo DC bus
Crane, metallurgia, conveyor multi-drive common DC bus systems
UPS & Alimentatori industriali
Industrial online UPS, bidirectional DC/DC converters
High-frequency switching power supplies, galvanica & electrolysis power supplies
High-power SSR solid-state relay circuit protection
Saldatura & Special Power Supplies
Inverter welding machines, plasma power supplies, high-frequency heat treatment power supplies, IGBT power board protection
Other Power Electronic Equipment
Active Power Filter APF, Static Var Generator SVG power modules
Energy feedback units, unità di frenatura (braking IGBT protection)
- Differenziazione della selezione (F vs FI)
FWP-25A22F (questo modello, no striker): Preferred for DC bus >500V, no alarm demand, vantaggio di costo.
FWP-25A22FI (with striker): For AC or DC ≤500V, when fuse alarm, PLC interlock and fault reporting are required.
- Applicazioni vietate
- General distribution circuits, illuminazione, heating loads (aR does not protect overload; low overload will not melt and may damage downstream equipment)
- Tensione CC >700V
- Circuits requiring overload protection without separate thermal / protezione elettronica da sovraccarico
- Direct replacement of gG distribution fuses (gG high I²t risks IGBT destruction)
Eaton Bussmann FWP Cylindrical High-Speed Fuse List (22×58mm series, matching FWP-25A22FA)
Nota: A = aR (semiconductor short-circuit, 700VAC/700VDC); G = gR (full range, sovraccarico + cortocircuito, 690VCA); suffix F = no striker, FI = with striker. FA in trade name refers to original F; AMPxx is only current marking.
- FWP-xxA22F / FWP-xxA22FI (aR, 700VAC/700VDC, 22×58mm)
| Corrente nominale | No Striker Model | With Striker Model | Pre-arcing I²t | Total I²t @700VAC | Power Dissipation W |
| 20UN | FWP-20A22F | FWP-20A22FI | 22 | 310 | 5.2 |
| 25UN | FWP-25A22F | FWP-25A22FI | 37 | 530 | 6 |
| 32UN | FWP-32A22F | FWP-32A22FI | 55 | 780 | 8 |
| 40UN | FWP-40A22F | FWP-40A22FI | 68 | 960 | 12 |
| 50UN | FWP-50A22F | FWP-50A22FI | 155 | 2200 | 12.5 |
| 63UN | FWP-63A22F | FWP-63A22FI | 280 | 4000 | 15 |
| 80UN | FWP-80A22F | FWP-80A22FI | 550 | 7800 | 15 |
| 100UN | FWP-100A22F | FWP-100A22FI | 1100 | 15600 | 16.5 |
⚠️ FI version DC rating derated to 500V. Do not use FI for DC >500V; use F version.
- FWP-xxG22F / FWP-xxG22FI (gR, 690VCA, 22×58mm, sovraccarico + cortocircuito)
| Corrente nominale | No Striker Model | With Striker Model | Pre-arcing I²t | Total I²t @690VAC | Power Dissipation W |
| 20UN | FWP-20G22F | FWP-20G22FI | 26 | 165 | 4 |
| 25UN | FWP-25G22F | FWP-25G22FI | 43 | 274 | 3.7 |
| 32UN | FWP-32G22F | FWP-32G22FI | 97 | 616 | 4.9 |
| 40UN | FWP-40G22F | FWP-40G22FI | 180 | 899 | 4.5 |
| 50UN | FWP-50G22F | FWP-50G22FI | 283 | 1362 | 6.3 |
| 63UN | FWP-63G22F | FWP-63G22FI | 516 | 2575 | 7.4 |
| 80UN | FWP-80G22F | FWP-80G22FI | 1092 | 5448 | 8.4 |
| 100UN | FWP-100G22F | FWP-100G22FI | 2065 | 10300 | 9.4 |
- Other FWP Cylindrical Ferrule Sizes
- 10×38mm: FWP-xxA10F / FWP-xxG10F, current range 4~32A
- 14×51mm: FWP-xxA14F / FWP-xxG14F, current range 4~50A
Protection class aR / gR same as above; voltaggio: 700V(aR) / 690V(gR)
- Other Eaton Bussmann High-Speed Semiconductor Fuse Series (Bolt / Blade Style, Corrente elevata)
FWP (bolt-on): 700V, 35~600A, aR, busbar and high-power converter
FWJ: 1000V, high-voltage DC, PV & energy storage high-power
FWH: 1000Vdc high-voltage DC fuse
FWA: 500V, small cylindrical high-speed
FWX: 250V, North American blade high-current
DFJ: Drive dedicated high-speed fuse
- Matching Fuse Holders (22×58)
JM70100: Standard holder (for F version)
JM70100 + microswitch module: For FI striker version, dry contact alarm output
- Model Code Summary
FWP Current + A/G + Codice taglia + F/FI
FWP: Bussmann IEC high-speed semiconductor fuse
UN: aR (short-circuit only, IGBT/SCR protection)
G: gR (full range, sovraccarico + cortocircuito)
22 = 22×58mm; 14 = 14×51mm; 10 = 10×38mm
F: No striker; FI: With striker
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