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Standard Surge Inrush Current Limiter NTC Thermistor 2D-9 for Residential Commercial Industrial Healthcare Electric Vehicle
Overview
When you switch on an electrical device, it goes through an initial surge of current, also called inrush current. If this surge is too strong, it can harm the device. Inrush Current Limiters (ICLs) work by raising the circuit’s resistance when there’s a lot of current. This reduces the current flow and shields the device. Many applications, including power supplies, motors, and other devices that experience high inrush currents, frequently rely on ICLs. They play a critical role in safeguarding various electrical devices, preventing damage, and keeping power surges in check.
Aadvantages of using inrush current limiters
1. Shield devices from damage caused by inrush current.
2.Stop power surges.
3. Power supplies work more efficiently.
4. Act as cost-effective protection.
If you’re designing an electrical device that’s susceptible to high inrush current, it’s a good idea to include an inrush current limiter. It’s a straightforward and effective way to guard your device against potential harm
Specification
| Name | NTC Thermistor |
| Series | MF72/MF71/AS |
| P/N | 2D-9 |
| Resistance @25C | 2 Ohms |
| Resistance tolerance | 20% |
| Max stable current | 4.5A |
| Operating temperature | -40~+170C |
| B25/85 | 2700K |
| Color | Black |
| Coating | PF Resin |
Solution – Inrush Current Limiter
Use an Inrush Current Limiting Thermistor.) to address the overload scenario of the sample problem:
- As per Step 3 above, the inverter wattage needed including the overload condition > 1500W
- Since max output power allowed is 1000W
- Allowed current: 8.0A, 50 # 2 at 120V
- Normal continuous current per appliance = 300W/120V = 2.50A
- Due to inrush current = 2.50A x 3 = 7.50A
- Duration of inrush = one cycle = 1 x 1/50 sec = 0.02 sec
- Energy of the thermistor = 120V x 7.50A 0.02 sec = 18.0 J
- Note: The energy requirement, mentioned above, is needed to handle without self destruction.
- So, for three appliances that start up at the same time, we need 3.0 x 18.0 J = 54 J
- Minimum resistance: 120 V x 1.414/8.0A = 21.21Ω (This ensures that the current does not exceed 8.0 A.)
- So if we assume Ambient of 50°C, Min Resistance = 40Ω, so we can reconnect
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