300A DC odklopnik MCCB za DIY baterijske škatle | 2-polni baterijski izolator, zaloga EU

A 300A DC circuit breaker does one job your BMS cannot do on its own: it gives you a physical break in the circuit. Vaš BMS ščiti celice pred prekomernim tokom in kratkimi stiki, vendar ko morate delati na paketu, izolirati inverter ali izklopiti napajanje v sili, potrebujete nekaj, kar lahko dejansko izklopite. Ta 2-polni DC odklopnik sedi med vašo baterijo in inverterjem, doda zaščito pred kratkim stikom poleg BMS in vam daje vidno točko za odklop.

Why a 300A DC Circuit Breaker Beats Relying on the BMS Alone

BMS je zaščitna naprava, ne stikalo. Prekine tok, ko nekaj ni v redu, vendar vam ne omogoča, da po potrebi izolirate paket — in ne bo odpravil trdega kratkega stika na glavni DC napajalni liniji tako kot odklopnik. Dodajanje odklopnika vam prinese tri stvari, ki jih BMS sam ne more:

• Ročni odklop za vzdrževanje, nadgradnje in nujne primere
• Odpravljanje kratkega stika ocenjeno na 7,5kA
• Napaka, ki jo lahko vidite — sprožen odklopnik vam pokaže, da se je nekaj zgodilo, namesto da bi vas pustil ugibati

AC odklopniki ne sodijo v baterijsko vezje

To je največja napaka. Izmenični tok prehaja skozi ničlo 50-60 krat na sekundo, in ta ničelni prehod omogoča AC odklopniku, da ugasne oblok, ko se sproži. Enosmerni tok nima ničelnega prehoda, zato oblok še naprej gori. AC odklopnik lahko ne uspe odpraviti napake v baterijskem sistemu, kar je prav situacija, ki jo mora odklopnik rešiti.

Choosing a 300A DC Circuit Breaker for High-Output Systems

300A is the top of this series. Choose it when your system genuinely runs at that level:

• You run a 300A BMS
• You have an inverter drawing close to the BMS limit on a continuous basis
• You are running more than one inverter, or plan to add one
• Your load profile is high and sustained rather than short bursts
• You want no margin compromise — the breaker stays above everything downstream

One warning that matters more than the table: at 300A the cable becomes the bottleneck. A 300A breaker does not make an undersized cable safe — size the cable for the current first, and make sure your terminals and busbars are rated for it too.

Branje etikete: DC ocena in zmogljivost prekinjanja

Fitting a DC Circuit Breaker Into a DIY Battery Box

At 78 × 38 × 63mm and 225g, this breaker fits inside a battery enclosure or a tight cabinet instead of needing its own panel.

1. Mount it where you can reach it. A breaker you cannot access is decoration.
2. Follow the LINE and LOAD markings, and confirm the wiring diagram in the manual before connecting.
3. Torque the terminals to spec and re-check after the first thermal cycle.
4. Keep AC and DC separate. This device goes on the DC side between battery and inverter; the AC output side needs its own AC breakers.
5. Check heat at full load. High-current builds warm up; leave airflow around the breaker and check terminal temperature after the first hour at full load.

Specifikacije

Ni vključeno: the battery box, the BMS and the battery cells. This listing is the circuit breaker only.

Pogosta vprašanja

Which systems need a 300A DC circuit breaker?
300A BMS builds, systems with inverter loads running close to the BMS limit, and installations with more than one inverter.

Can I use a smaller breaker to save money?
No. A breaker rated below your system’s continuous current will nuisance-trip. Size at or just above your continuous current.

Can I use an AC breaker on a battery circuit instead?
No. DC arcs do not self-extinguish, so an AC breaker may fail to clear a fault. This device is DC-rated at 125/250V DC.

How much short-circuit current can it clear?
7.5kA (Icu/Ics).

Will it fit inside my battery box?
At 78 × 38 × 63mm and 225g it fits most DIY enclosures. Send us the mounting space if you are unsure.

Do you make other ratings?
Yes — 220A (BCPS2DM220) and 250A (BCPS2DM250) in the same series.

Does it come with the box, BMS or cells?
No. This listing is the breaker only.

Related: Battery Box Parts and Accessories

Building a complete pack? Pair the breaker with a DIY battery box kit, a battery box base, a set of battery box wheels, and a JK BMS heating pad if you charge in cold weather. Cells in 280Ah, 314Ah and 320Ah are available from the same warehouse.