High accuracy current transformer light weight, small size and cheap price, current ratio 30:5A, 75:5A, 200;5A, 500:5A to 800:5A. Current transformer is mainly used for indoor or distribution box, rated frequency 50/60Hz.
Note: The installation method of current transformer can be fixed by busbar and fixed by the bottom plate, suitable for installation in any direction. The primary conductor can be busbar or cable.
Specification:
| Model | ATO-CT-40I | |||
| Weight | 1kg | |||
| Current Ratio (A) | VA Secondary load/ Burden (VA) | Cross-core Turn Number | ||
| 0.2 | 0.5S | 0.2S | ||
| 200-300/5 | 2.5 | 2.5 | 2.5 | 1 |
| 300-450/5 | 2.5 | 2.5 | 2.5 | 1 |
| 500-800-5 | 5 | 5 | 5 | 1 |
| Rated Frequency | 50/60Hz | |||
| Rated Test Voltage | 3kV AC (1min) | |||
| Rated Short-Time Thermal Current (ith) | 60 in | |||
| Rated Dynamic Current (idyn) | 2.5 lth | |||
| Rated Voltage (Um) | 0.66 kV AC | |||
| Continuous Overload (ld) | 1.2 in | |||
| Operating Temperature | -10℃~50℃ | |||
| Housing Self-Extinguishing Class | VO | |||
| Safety Factor | FS 5 | |||
| Secondary Current | 5A/ 1A | |||
| Bus Specification (mm)/Number | / |
Dimension (unit: mm)
| Model | Dimensions | Perforation size | Installation size | |||||
| W | H | D | a | e | φ | M | N | |
| ATO-CT-30I | 62 | 78 | 45 | 32 | 11 | 22 | 40 | 57.5 |
| ATO-CT-3030I | 85 | 102 | 50 | 32 | 11 | 28 | 57.5 | |
| ATO-CT-40I | 75 | 95 | 45 | 42 | 11 | 31 | 40 | 57.5 |
| ATO-CT-60I | 102 | 130 | 45 | 61.5 | 21 | 45 | 42 | 57.5 |
| ATO-CT-60II | 102 | 125 | 45 | 31 | 33 | / | 42 | 57.5 |
| ATO-CT-80I | 118 | 140 | 45 | 82 | 11 | 52 | 60 | 57.5 |
| ATO-CT-100II | 145 | 125 | 45 | 103 | 35 | / | 80 | 57.5 |
Tips: How to measure the polarity of current transformer?
- DC MethodConnect the positive and negative electrode of a 1.5～3V battery with the primary coil L1 and L2 of the transformer respectively, connect the transformer’s secondary side K1, K2 respectively with the positive and negative electrode of a milliammeter. After the loop is well connected, the indicator of milliammeter turns clockwise while connecting K, and turns anticlockwise while disconnecting K, that means the transformer’s terminal connecting with the positive electrode of the battery has the same polarity with the terminal connecting with the positive end of the milliammeter, namely L1 and K1 have a same polarity and the transformer is a subtractive polarity. If the indicator turns conversely to the above, the transformer is an additive polarity.
- AC MethodConnect the L2 and secondary side K2 of the current transformer’s primary and secondary coil with wires, then add an 1～5V AC voltage to the secondary side, measure the U2 and U3 with a voltmeter below 10V, if U3=U1-U2, the transformer is a subtractive polarity; if U3=U1 U2, the transformer is an additive polarity.
- Meter MethodGenerally, the transformer calibrator is equipped with a polarity indicator, it can test the polarity in advance before measuring the current transformer error. If the indicator has no indication, meaning that the polarity of the tested current transformer is correct. (subtractive polarity)
