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    3 Pole Molded Case Circuit Breaker, 250A/ 300A/ 350A/ 400A

    5 out of 5 based on 3 reviews | Write a review
    3 pole molded case circuit breaker for sales online. Mccb circuit breaker with rated operating voltage 380/415V AC, 50Hz/ 60Hz, operating temperature from -25℃ to 50℃. The 400 amp mccb can be used for conversion of line and infrequent starting motor.
    SKU: ATO-MCCB-4003P
    30-day Returns
    Free Shipping
    Delivery date: 6-12 days

    Factory price molded circuit breaker with 50 kA short circuit interrupting capacity, max. rated surrent 400A, IP 20 protection grade. Mccb breaker has advantages of high reliability, low failure rate, long overhaul period and low maintenance workload.

    Molded Case Circuit Breaker Information

    • Model: ATO-ABE-403b
    • Max. rated Current: 400 amp
    • Rated Voltage: 380/415V AC, 50Hz/ 60Hz
    • Number of poles: Three pole
    • 50 kA short circuit interrupting capacity


    Standard Certifications IEC60947 GB14048
    Electrical Parameters Model ATO-ABE-403b
    Rated Current 250A, 300A, 350A, 400A
    Numbers of Poles 3 Pole
    Rated Operating Voltage 400V
    Rated Insulated Voltage (Ui) 800V
    Rated Frequency 50Hz/ 60Hz
    Ultimate Short Circuit Breaking Capacity, Icu DC 125V 20kA
    250V 10kA
    AC 50Hz/ 60Hz 230V 35kA
    380V 30kA
    415V 25kA
    440V 25kA
    480V 18kA
    600V 18kA
    Mechanical Parameters Electrical Life 1500 times
    Mechanical Life 8500 times
    Protection Degree IP20
    Operating Temperature -25℃~+50℃
    Weight 7.5kg

    Dimension (Unit: mm)

     Diemension of molded case circuit breaker      Diemension of molded case circuit breaker 1 Diemension of molded case circuit breaker 2     

    Model Dimensions Mounting Dimensions
    C C1 E F G G1 H H1 H2 H3 H4 H5 L L1 L2 W W1 W2 A B Φd
    ATO-ABE-403b 128 174 89 66 31 12 107 162 38 6 5 4.5 257 459 224 150 48 195 44 194 7


    3 Pole Molded Case Circuit Breaker,250A-400A Details

    Tips: Troubleshooting of Molded Case Circuit Breaker.

    If there is no short circuit or direct grounding in the system, and the relay protection does not act, the circuit breaker will automatically trip, which is called "mistrip" of the circuit breaker. The analysis, judgment and treatment of "misjumping" are generally divided into the following three steps.

    1. According to the following characteristics of the accident phenomenon, it can be judged as "misjumping".
    (1) Before the trip, the meter and signal indicate normal, indicating that there is no short-circuit fault in the system.
    (2) After the trip, the green light flashes continuously and the red light goes out. The ammeter and active and reactive power meters of the circuit breaker circuit indicate zero.

    2. Find out the reasons and deal with them separately.
    (1) If the protection panel is automatically tripped due to accidental touch, misoperation, or mechanical vibration caused by external force vibration, the cause of the switch failure should be eliminated and the power should be sent immediately.
    (2) For other electrical or mechanical part failures, and the power transmission cannot be restored immediately, the dispatcher and relevant leaders should be contacted to stop the "mistrip" circuit breaker and transfer it to overhaul.

    3. Check and analyze electrical and mechanical faults of the "false trip" circuit breakers.
    (1) The causes of electrical faults include:
    a. Protection malfunction or improper positioning, or current and voltage transformer loop failure;
    b. The insulation of the secondary circuit is poor, and the DC system is grounded at two points (the trip circuit is grounded at two points).
    (2) The causes of mechanical failures include:
    a. The closing maintenance bracket and the opening lock cannot be maintained, causing a trip;
    b. Hydraulic machinery a branch gate valve and check valve at the first level of poor sealing, leakage, should have been closed to maintain the oil supply from the hole to the upper end of the second valve in order to maintain the broken senator in the closed position, but when the amount of oil leakage exceeds the amount of supplementary oil, the pressure at the upper and lower ends of the second valve caused by different. When the pressure in the upper part of the second stage of the study is less than the pressure in the lower part, the second stage valve will automatically return, and the return of the second stage valve will cause the work cylinder to close the high pressure oil in the cavity to drain, so that the circuit breaker tripped.

    Existing reviews of 3 Pole Molded Case Circuit Breaker, 250A/ 300A/ 350A/ 400A
    High quality molded case circuit breaker
    These remain a trusted molded case circuit breaker because of how easy they are to install and how durable they are. In all the years they've been around, we've never replaced a single one that we previously installed.
    From: Monzer | Date: 07/12/2022
    Was this review helpful? Yes No (0/0)
    Works great. So far so good.
    The 3P MCCB was new in the box and arrived in two days. It was easy to install and is performing its intended task. So far so good. Better price than big box store.
    From: Stults | Date: 29/06/2022
    Was this review helpful? Yes No (0/0)
    The mccb worked Very Well!!
    The 250A 3P MCCB was new in the box and arrived in two days. It was easy to install and is performing its intended task.
    From: lzs | Date: 13/05/2022
    Was this review helpful? Yes No (0/0)
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