The technical data of an iUCB-DC4820-01 circuit breaker being tested are as follows:
Absolute Maximum Ratings
| Parameter |
Value |
Unit |
| Maximum Input Voltage |
-75 |
VDC |
| Minimum Input Voltage |
-18 |
VDC |
| Maximum Voltage between the ON/OFF and COM.I leads |
75 |
VDC |
| Maximum Voltage between the ACTIVE and COM.O leads |
75 |
VDC |
| Maximum ACTIVE lead Current |
5 |
mADC |
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Electrical Characteristics at 25 °C
| Parameter |
Min |
Type |
Max |
Unit |
| Operating Voltage Range |
-18 |
|
-60 |
VDC |
| Max. Load Current |
|
|
20 |
A |
| Current Limiting Level |
24 |
|
26 |
A |
| Max On-state Resistance |
|
0.008 |
0.01 |
Ohms |
| Max. On-State Voltage Drop |
|
0.16 |
0.2 |
VDC |
| Max. Off-State Leakage Current |
|
0.1 |
0.3 |
mA |
| Under-voltage Threshold LOW to activate Protective Cut-Off |
35 |
|
36 |
VDC |
| Under-voltage Threshold HIGH to inactivate Protective Cut-Off |
40 |
|
41 |
VDC |
| Over-voltage Threshold HIGH to activate Protective Cut-Off |
57 |
|
58 |
VDC |
| Over-voltage Threshold LOW to inactivate Protective Cut-Off |
56 |
|
57 |
VDC |
| Soft Turn-On Time |
|
500 |
|
µs |
| Soft Turn-Off Time |
|
500 |
|
µs |
| Current Limiting Response Time |
|
50 |
|
ns |
|
Fig. 1 illustrates a circuit diagram designed for testing the iUCB-DC4820-01 device.
To carry out the test, the following tools and components should be provided:
- Variable Voltage Regulated Power Supply capable of providing an output voltage from
30 to 60 VDC and output current greater than 30 Amps
- Capacitor C of 22,000 µF rated for 63 VDC
- Load Resistor RL of 100 Ohms rated for 25 Watts to simulate a constant load
- Non-inductive Load Resistors ROL of 1.0 Ohm, 1.6 Ohm and 2.4 Ohm rated for 25 Watts each
- Micro-ohmic resistor RSH of 0.002 Ohm ±1%
- MOSFET Q1 type IRF2807
- Double-channel Pulse Oscillator (Ch1 & Ch2)
- Double-channel Oscilloscope type THS720P
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Fig. 1 - Test Circuit
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An output of Variable Voltage Regulated Power Supply should be set for 48 Vdc.
Since iUCB-DC4820- 01 device is tested in a pulse way, then Pulse Oscillator controls should be set for pulse
duration and inter-channel time-shift as shown in Fig. 2. A period of pulses should be set for 2…3 sec.
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Fig. 2 - Pulse Oscillator Waveforms
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Pulse Oscillator output Ch2 enables the circuit-breaker for 15 ms.
Past 3 ms after the circuit-breaker has been enabled, Pulse Oscillator output Ch1 enables the MOSFET Q1
to connect an additional Load Resistor ROL to the output of the circuit-breaker for 3 ms.
During the test, Oscilloscope channel 1 monitors a value of current consumed from the Variable Voltage Regulated
Power Supply as a voltage drop across the resistor RSH, and its channel 2 monitors a value of voltage
drop across the POWER IN and POWER OUT leads.
The testing procedure is carried out for various values of resistor RSH, i.e. 2.4 Ohm corresponds to
nominal load, 1.6 Ohm and 1.0 Ohm correspond to over-current condition, 0 Ohm corresponds to short-circuit
condition.
Figs. 3…6 illustrates the duty waveforms according to the tests.
In every figure, a right-hand picture is provided to more clearly illustrate a turn-on transition of the MOSFET Q1.
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Fig. 3 - ROL=2.4 Ohm. No Current Limiting
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Fig. 4 - ROL=1.6 Ohm. Current Limitation at approximately 25A
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Fig. 5 - ROL=1 Ohm. Current Limitation at approximately 23A
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Fig. 6 - Short Circuit ROL=0 Ohm. Current Limitation at approximately 20A
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Circuit Breaker Test bed Configuration and Results
