English
Español
| Categories | Economic 4.5KA, 6kA Regular Series Circuit Breaker |
| Model | SFM3-125 DC 125A |
| Rated current(A) | 1,2,3,4,6,10,16,20,25,32,40,50,63 |
| Frame size Rated current(A) | 63A, 125A |
| Number of poles | 1P, 2P |
| Breaking current | 10000 |
| Time costant | 10 |
Application
● The maximum ambient air temperature does not exceed +40C, minimum is not less than -5C,and the average value does not exceed +35C.
● The altitude of the installation site does not exceed 2000m.
● The relative humidity of the atmosphere does not exceed 50% at the maximum ambient temperature of +40C. Relative humidily at high temperatures can be relatively high. The monthly average maximum relative humidity of the wettest month is 90%, and the monthly average of the month The minimum temperature is +25C and takes into account condensation that occurs on
● Pollution levelis 2.
● Installation categories are I, II.
● Use TH35- 7.5 steel mounting rails for installation.
● The inclination of the mounting surface and the vertical surface does not exceed 5°.
● Screw the wire tight.
Construction and Feature
SFM3-DC DC circuit breaker is composed of outer casing, operating mechanism, thermal release，electromagnetic tripping contact system, arc extinguishing system, etc. It has overload and short circuit protection functions, unique design structure and powerful permanent magnet arc extinguishing system. The product has a short circuit capability of 10kA and a mechanical life of more than 20,000 times. The appearance of the product is beautiful. The mounting rail is a TH35-7.5 standard steel mounting rail, and has the following features: the handle is designed on the front side of the front end, and the operation is safe and strong. Feel comfortable, be sure to pay attention to the "+, -" polarity when wiring, the power supply goes in and out, in line with the characteristics of the power supply line, easy to install, saves the wire.
Technical Data
| Table 1 | ||||||
| Frame size rated current | Pole | Rated voltage | Rated current | Rated ultimate short circuit capability | Instantaneous release current | |
| Breaking current | Time constant | |||||
| 63 | 1 | DC250V | 1,2,3,4,6,10,16,20,25,32,40,50,63 | 10000 | 10 | 8ln-12ln |
| 2 | DC500V | |||||
| 125 | 1 | DC250V | 80,100,125 | 10000 | 10 | 8ln-12ln |
| 2 | DC500V | |||||
Standard time-current
| Table 2 | ||||||
| Test | DC test current | Initial state | Time limit | Expected result | Remark | |
| a | 1.05ln | Cold state |
t≥1h(ln≤63A) t≥2h(ln>63A) |
No tripping | ||
| b | 1.3ln | Right after test number a |
t<2h(ln>63A) t<1h(ln≤63A) |
tripping | ||
| c | 8ln | Cold state | t≥0.2s | No tripping | ||
| 12ln | t<0.2s | tripping | ||||
Wiring diagram
Dimensions
> Application Guide for Hydraulic Magnetic Circuit Breakers in Sensitive Electronic Equipment
Why use hydraulic magnetic breakers for medical, IT or telecom equipment? Temperature stability, delay curves, and selection tips.
> What Is a Shunt Trip and How Does It Work with MCCB?
Learn what a shunt trip is, how it remotely trips an MCCB, typical voltages, and common applications like emergency stop systems.
> Guide to Selecting a Surge Protective Device (SPD) for EV Charging Stations
Protect EV chargers from lightning and switching surges. Learn how to choose the right SPD type, voltage protection level, and coordination.
> How to Fix a Tripping RCBO in Commercial Distribution Boards
RCBO tripping repeatedly? Learn 6 common causes and practical fixes for commercial panels. No more nuisance trips.