Product Description
The 5D, 7D, 10D, 14D and 20D metal oxide varistors (MOVs) protect electrical and electronic equipment against lightning surges, switching surges and other transient overvoltages.
When the applied voltage remains below the varistor threshold, only a very small leakage current passes through the component. When the voltage exceeds the threshold, the varistor’s resistance decreases rapidly, allowing it to absorb and divert surge energy to protect downstream circuits.
Product Types
Surge Suppression Type
Designed to suppress random, non-periodic transient overvoltages caused by lightning strikes, switching operations and similar events. These surges may produce very high peak voltage and current.
High-Power Type
Designed to absorb repetitive pulse groups, such as periodic switching spikes generated by switch-mode power converters. Although each voltage peak may be moderate, the high repetition rate can produce substantial average power.
High-Energy Type
Designed to absorb magnetic energy released by large inductive loads, including generator excitation coils, lifting electromagnets and other high-inductance coils. Energy-absorption capability is the primary selection factor.
Key Features
- Fast response to transient overvoltage.
- High surge-current handling capability.
- Wide varistor-voltage selection.
- Excellent energy-absorption performance.
- Low standby leakage current.
- Compact radial-leaded disc construction.
- Available in 5 mm, 7 mm, 10 mm, 14 mm and 20 mm disc sizes.
- Suitable for power supplies, appliances, industrial equipment and automotive electronics.
Working Principle
When the applied voltage is lower than the varistor voltage, the current flowing through the MOV is extremely small and the device behaves like a high-resistance component.
When the applied voltage exceeds the varistor threshold, the current increases rapidly and the resistance drops sharply. The MOV then diverts the surge current and clamps the voltage to a safer level.
Electrical Parameter Definitions
| Parameter | Description |
|---|---|
| Varistor Voltage V1mA | Voltage measured when a DC current of 1 mA passes through the varistor |
| Maximum Allowable AC Voltage | Maximum continuous RMS AC operating voltage |
| Maximum Allowable DC Voltage | Maximum continuous DC operating voltage |
| Clamping Voltage Vc | Maximum voltage across the varistor at the specified 8/20 μs impulse current |
| Test Current Ip | Impulse current used to measure clamping voltage |
| Energy Rating | Maximum absorbable energy under 10/1000 μs or 2 ms pulse conditions |
| Surge Current | Maximum current capacity under an 8/20 μs impulse |
| Rated Power | Maximum continuous power dissipation |
| Capacitance | Reference capacitance measured at 1 kHz |
Series Dimensions
| Series | Maximum Disc Diameter | Maximum Height | Minimum Lead Length | Lead Spacing | Lead Diameter |
|---|---|---|---|---|---|
| 5D | 7.5 mm | 9.5 mm | 25 mm | 5 ±1 mm | 0.6 ±0.02 mm |
| 7D | 9 mm | 11 mm | 25 mm | 5 ±1 mm | 0.6 ±0.02 mm |
| 10D | 13 mm | 15 mm | 25 mm | 7.5 ±1 mm | 0.8 ±0.02 mm |
| 14D | 17 mm | 19 mm | 25 mm | 7.5 ±1 mm | 0.8 ±0.02 mm |
| 20D | 23 mm | 25 mm | 25 mm | 10 ±1 mm | 1.0 ±0.02 mm |
5D Series Maximum Thickness
| Model Range | Maximum Thickness |
|---|---|
| 180K–680K | 5.0 mm |
| 820K–201K | 5.0 mm |
| 221K–331K | 5.5 mm |
| 361K–471K | 6.0 mm |
| 511K–561K | 6.5 mm |
| 621K–681K | 7.0 mm |
7D Series Maximum Thickness
| Model Range | Maximum Thickness |
|---|---|
| 180K–680K | 5.0 mm |
| 820K–201K | 5.0 mm |
| 221K–331K | 5.5 mm |
| 361K–471K | 6.0 mm |
| 511K–561K | 6.5 mm |
| 621K–681K | 7.0 mm |
| 751K–821K | 7.5 mm |
10D Series Maximum Thickness
| Model Range | Maximum Thickness |
|---|---|
| 180K–680K | 5.0 mm |
| 820K–201K | 5.0 mm |
| 221K–331K | 5.5 mm |
| 361K–471K | 6.0 mm |
| 511K–561K | 6.5 mm |
| 621K–681K | 7.0 mm |
| 751K–821K | 7.5 mm |
| 102K–122K | 8.0 mm |
| 142K–162K | 10 mm |
| 182K | 12 mm |
14D Series Maximum Thickness
| Model Range | Maximum Thickness |
|---|---|
| 180K–680K | 5.0 mm |
| 820K–201K | 5.0 mm |
| 221K–331K | 5.5 mm |
| 361K–471K | 6.0 mm |
| 511K–561K | 6.5 mm |
| 621K–681K | 7.0 mm |
| 751K–821K | 7.5 mm |
| 102K–122K | 8.0 mm |
| 142K–162K | 10 mm |
| 182K | 12 mm |
20D Series Maximum Thickness
| Model Range | Maximum Thickness |
|---|---|
| 180K–680K | 5.0 mm |
| 820K–201K | 5.0 mm |
| 221K–331K | 5.5 mm |
| 361K–471K | 6.0 mm |
| 511K–561K | 6.5 mm |
| 621K–681K | 7.0 mm |
| 751K–821K | 7.5 mm |
| 102K–122K | 8.0 mm |
Available Electrical Range
The supplied specification includes models covering approximately:
| Item | Available Range |
|---|---|
| Varistor Voltage | 15.5–1,980 V |
| Maximum Continuous AC Voltage | 11–1,000 VAC |
| Maximum Continuous DC Voltage | 14–1,465 VDC |
| Clamping Voltage | 38–2,970 V |
| Disc Series | 5D / 7D / 10D / 14D / 20D |
Actual clamping voltage, impulse current, energy rating, surge-current capacity, rated power and capacitance depend on the selected model and disc diameter.
Applications
- AC and DC power systems
- Surge protectors and power strips
- Lightning and switching-surge suppression
- Security and surveillance systems
- Electric motor protection
- Automotive electronic systems
- Switching power supplies
- Industrial control equipment
- Communication equipment
- Household electrical appliances
