How to select metal oxide varistors for overvoltage protection?

Power Circuit Protection
, ,
1

When specifying a MOV for your application, a primary focus should be surge-handling capacity.
Regarding the surge-handling capacity, refer to the specification sheet for your device. For example, a surge could be specified as 6KV/3KA. Generally, a 14mm varistor is selected. Leave a voltage margin of around 1.4 - 1.7 times your expected working value.

DigiKey Part Number F6419-ND
Manufacturer Littelfuse Inc.
Manufacturer Product Number V14P17AUTO
Detailed Description 27 V 3 kA Varistor 1 Circuit Through Hole Disc 14mm
Datasheet Datasheet

image
image390×390 26.9 KB

According to the specification sheet:

The V14P17AUTO can withstand a surge current of 3kA, has a diameter of 14mm, and an effective voltage VRMS of 17V.
If we take a margin of around 1.4 times, it can be used in circuits with a voltage below 12V.

image
image865×300 141 KB

More Littelfuse circuit protection products

Littelfuse Circuit Protection products provide stable and reliable signal transmission guarantee for all kinds of precision electronic devices by virtue of their precise adjustment relationship with capacitance, dynamic resistance, etc. in terms of high-frequency characteristics, and their performance is excellent in the industry.

More Q&A on Littelfuse Circuit Protection Products Technology:

I. Questions Related to Component Characteristics

  1. What are the classifications of gas discharge tubes?

  2. Littelfuse new MOV+Sidactor thyristor vehicle charging solution technological innovations

  3. In Littelfuse circuit protection products, what kind of current is I in I²t?

  4. What are the differences between discharge tubes and metal oxide varistors?

II. Questions Related to Selection

  1. How to select metal oxide varistors for overvoltage protection?

  2. Do Littelfuse overcurrent protection fuses/circuit breakers have self-resetting function?

  3. The difference in the selection of overvoltage / overcurrent between AC and DC input terminals?

  4. When to Use PTC Resettable Fuses and Metal Fuses?

  5. What parameters differ between surface mount and through hole fuse selections?

  6. Under what general circumstances can AC components be directly used in DC circuits?

  7. Can the method of paralleling small-capacity fuses be used to achieve the purpose of fast fusing?

III. Questions Related to Applications

  1. What design requirements for overcurrent and overvoltage protection?

  2. In which fields are gas discharge tubes mainly applied? Do they have directionality?

  3. Are overcurrent and overvoltage protection for AC/DC power inputs used in charging piles?

  4. Can Littelfuse Circuit Protection Products Protect Against Overvoltage and Overcurrent?

  5. How to understand the fuse explosion-proof test?

  6. How to specifically know the time of time-delay fusing fuses?