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waqar ahmed
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Join Date: Jan 2012
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How To Calculate The Surge Current?

02/05/2012 11:28 AM

if i want to put SPD in my Main Power Line the how to calculate the Surge Current? is it depend on the load current or there is some other factor.
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lyn
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#1

Re: How to Calculate the Surge Current?

02/05/2012 11:34 AM

Inrush current - Wikipedia, the free encyclopedia
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SolarEagle
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#2

Re: How to Calculate the Surge Current?

02/05/2012 11:38 AM

What's SPD?

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Firas Atwan
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#3
In reply to #2

Re: How to Calculate the Surge Current?

02/05/2012 12:01 PM

SPD: Surge Protection Device

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wareagle
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#4

Re: How To Calculate The Surge Current?

02/05/2012 4:36 PM

It depends on the thousands of amps in the lightning stroke. You need something like this http://www.deltasurgeprotectors.com/?gclid=CIa7g4rkh64CFQwj7AodWVqy2Q

along with this http://tech.pronto.com/mpm/shop/surge-surge-suppressor/c-v1_2_30_154?adid=1203057250-4828622-0_gs&creativeid=3657104627&ref=surge+surge+suppressor&site=
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mandi
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#5

Re: How To Calculate The Surge Current?

02/06/2012 12:02 AM

http://www.electrical-installation.org/enwiki/Surge_protection_technical_supplements

http://www.electrical-installation.org/enwiki/SPD_and_external_SCPD_coordination_table
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NotUrOrdinaryJoe
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#6

Re: How To Calculate The Surge Current?

02/06/2012 11:49 AM

Well, to calculate the Surge Current you must know the current density of the bolt of lightning. You will have to have to move at the speed of light to measure the width of the arc, but you will burst into flame any due to the air resistance as you accelerate up to the speed of light. So, it won't matter.

Actually, it works like this. Inside s SPD are MOV resistors that short the main to ground (or neutral) above a certain voltage. The more of those that you have in parallel, the more current you can take before one goes "pop!" and dies.

When you have destroyed all of those, you no longer have protection. Obviously, it is better to have more than you could possibly need. Start somewhere around 20,000 amps and go up from there if you want more insurance. Replace those after a couple of direct hits!

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PWSlack
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United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

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#7

Re: How To Calculate The Surge Current?

05/18/2023 2:54 AM

There are standards covering this sort of thing - British Standard 7671 for example.

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Firas Atwan (1); lyn (1); mandi (1); NotUrOrdinaryJoe (1); PWSlack (1); SolarEagle (1); wareagle (1)

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