My Account
FREE US SHIPPING5 Years Warranty

How much joule rating is enough for me?

Posted by Eshldty Official on

Surge protectors are an inexpensive way to protect your setup against power spike damage. There are some insights for you to learn more about surge protectors.

1. Lightning strike is a typical cause but not the only

Power spikes are fast, short duration electrical transients in voltage (voltage spikes), current (current spikes), or transferred energy (energy spikes) in an electrical circuit. Spikes are typically caused by

  • Lightning strikes
  • Power outages
  • Tripped circuit breakers
  • Short circuits
  • Power transitions in other large equipment on the same power line
  • Malfunctions caused by the power company
  • Electromagnetic pulses (EMP) with electromagnetic energy distributed typically up to the 100 kHz and 1 MHz frequency range.
  • Inductive spikes

Lightning that hits a power line can give 10k or more volts. A motor when switched off can generate a spike of 1,000 or more volts. There are many factors to cause a power spike, but your devices are not in danger all the time.

2. Surge protection system

The most effective place for surge suppression equipment is at the building’s electrical entrance panel. According to IEEE recommend, we should provide surge protection in three levels. First, power distribution cabinet, prevent high energy spike crush into the building grid. Second, distribution board, reduce the rest energy after first filter and reduce the internal spikes caused by device switch on/off. Last, the device adapter like phone charger or PSU, provide complete protection for electronic equipment.
All the three levels protection was provided already when you are use electronics in residential. That’s why your computer not damaged although you never used a surge suppressor for it.

3. About joule rating

The Joule rating number defines how much energy a MOV-based surge protector can theoretically absorb in a single event, without failure. Generally, the more joules the better, as this means the device can handle one large surge, or multiple smaller surges, before your device is in danger. But you may still find how much rating do you need, according to ANSI/IEEE C62.41 and UL 1449 (3rd). The energy of a power spike with 6,000 volts and 3,000 amps can be 90 joules. For the power spike caused by lightning hits, this number can be 1000 joules (20kV, 10kA). Considering the MOV matching so derating by 20% or more is usually required. So, the answer of how much joules can be enough is, you need at least 110 joules or 1200 joules, depends on prevents lightning or not.
Another thing you should to know is surge protectors doesn’t last forever. The joule rating will change every time it takes effect. There is no way for us to know how much protection it has left. If you've had your current surge protector for more than a few years, it's probably worth replacing. But you can use it for fans, lights, or toaster still.

Read more →

What Dose an IP Rating Mean?

Posted by Finn Young on

 Overview: This is a brief introduction about IP Code in Wikipedia, refer to the link below the article to view all about IP Code.


The IP Code, or Ingress Protection Code, classifies and rates the degree of protection provided by mechanical casings and electrical enclosures against intrusion, dust, accidental contact, and water.


For example, a product with IP46CH (maybe won't exist in theory), the 46CH followed IP means as follows the table.

1st: solid particle


> 1mm (Most wires, slender screws, large ants, etc.) cannot ingress

2nd: liquid ingress


Water projected in powerful jets no harmful effects. Test duration: 1 minute per square meter for at least 3 minutes

Water volume: 100 liters per minute (0.37 impgal/s) Pressure: 100 kPa (15 psi) at distance of 3 meters (9.8 ft)

3rd: additional


Tools > 2.5mm

4th: supplementary


High voltage apparatus

It means this high voltage apparatus device can prevent solid particles > 1mm ingress in usual, but tools < 2.5mm could ingress with personnel against. And it has the best waterproof level below the soak requirement.


According to standard. The 1st digit ranged from 0 (no protect) to 6 (complete protect) degree marked solid particle protection. The 2nd digit ranged from 0 (none) to 8 (Immersion, 1 meter / 3 ft / 3 in or more depth). And the optional 3rd / 4th letter for other protections. Those 2 digits allowed to replace with the letter X when insufficient data has been gathered to assign a protection level.

There used to be another number ranged from 0 to 9 for impact resistance degrees before the optional letters. It was replaced by IK code in standard EN 62262.


That’s all about the short introduction about IP code and IPX6. See also the link follows to learn more.

Ref: IP Code in Wikipedia

Read more →