熔斷器的合理選用

高壓限流熔斷器通常被人們認(rèn)為是一種結(jié)構(gòu)簡(jiǎn)單，保護(hù)可靠，投資較省的一種保護(hù)電器。實(shí)質(zhì)上，這種熔斷器雖然結(jié)構(gòu)簡(jiǎn)單，但必須以嚴(yán)格的工藝和質(zhì)量控制規(guī)范保證方能生產(chǎn)出可靠的高性能產(chǎn)品,同時(shí)還要正確的使用否則有可能導(dǎo)致它的保護(hù)功能喪失。以下簡(jiǎn)要介紹該產(chǎn)品的選用導(dǎo)則，欲了解詳情請(qǐng)與本公司聯(lián)系.
The high-Volt limit-current fuse generally is known as one protection electrical device with characteristics of simple structure,reliable protection and economical investment，however，actually though this type fuse has simple structure，this product with super performance only can be manufactured by means of strict technology and quality control norm, additionally,it is only
correctly using-it that can make full use of its normal protection function. this product’s use regulation would be introduced briefly below, anyone needing to have more information about it please contacts us．

對(duì)于熔斷器來(lái)講，使用時(shí)的安裝環(huán)境條件很重要，它不但影響熔斷器·性能，而且影響其可靠分?jǐn)喙收夏芰?。因此根?jù)使用條件要
加以正確的考慮.常見(jiàn)的一種安裝方式是把熔斷器安裝在一個(gè)三相封閉的箱體中，這時(shí)熔斷器須降容1 5％使用。額定電流小于20A的熔斷器可不
考慮降容，因?yàn)樾☆~定電流熔斷器發(fā)熱少，溫度低，封閉環(huán)境對(duì)其影響不大。還有一種安裝方式是把熔斷器單支封閉在一個(gè)絕緣樹(shù)脂澆注的筒內(nèi)，在這種情況下，熔斷器須容2 5％使用才能保證不使熔斷器過(guò)熱而損壞。額定電流2 0 A以下的熔斷器仍可不考慮降容。按照有關(guān)標(biāo)準(zhǔn)規(guī)定，熔斷器正常工作的環(huán)境溫度在-2 5℃—+4 0℃之間，當(dāng)溫度低于-2 5℃時(shí)熔斷器的機(jī)械性能將受到影響，而當(dāng)溫度高于+4 0℃時(shí)每升高1℃熔斷器應(yīng)降容1％使用。
對(duì)并聯(lián)熔斷器截流特性和I2t特性可遵循下式原則
lp總=n x(單—熔斷器預(yù)期電流lp／n時(shí)的l p1)
式中l(wèi)p總—并聯(lián)后的截流峰值；
n—熔斷器并聯(lián)數(shù)：
lp—預(yù)期電流有效值；
Ip1—單—熔斷器截流峰值
I2t總=n x(單—熔斷器預(yù)期電流lP／n時(shí)的I2t值)
需要注意是決不能把熔斷器簡(jiǎn)單的串聯(lián)使用在高一級(jí)的電壓電路中

The instalIment surrounding condition in use is very important for the fuse in that it not only affects the fuse’s perfo rmance,but also takes infuence on the reIiabIe abiIity of b reaking obstacle,therefore,operator should take the use condition into account．One common instalIment way is instalIing the fuse into case body with three-phase being sealed,at this time,thefuse should be decreased by 15 percent in capacity before used except the fuse with rated current being lower than 20A,because the fuse with smalI rated-current has Iittle heat radiated in addition to Iow-temperature,so the sealed surrounding does Iittle influence onto it．Another instalIment way is sealing one set of fuse into one tube poured with insuIation resin,under this circumstance, the fuse should be decreased by 25％in capacity before used in order to prevent the fuse from being damaged because of over-heated except for the fuse with rated current being Iower than 20 A According to relevant standard regulation,the normol work the fuse temperature of fuse ranges from-250℃ to 400℃,The fuse’s mechanical performabce would be affected positively provided the temperature is Iower than-25℃,vice versa,the fuse should be reduced by 1％in capacity per 1 Rise in temperature when the temperature is upper than 40℃before used.

As for the fuse installed in the cupboard with th ree-phase being not sealed,for the mutual interruption between temperature-
rising of th ree-phasefuse,the fuse could be decreased by 1 0％in capacity before used except for fuse with rated current being
lower than 20A．Generally, as for the fuse with rated current being lower than 10A，operator should do his best to make the fuse
away from landing metal support because of fuse-body’s easily-aging resulted from long-term co rona discharging . For
strengthening the current grade of fuse sometime，user would use two or three untis of fuse device for paralleling use,at this
time,the mutual influence between fuse’t emperature should be taken into account by operator,and the fuse should be decreased
by 10-20％in capacity for use generally.
The stem-current and 1²t properties of paralleling fuses can conform to following principle Ip-total：n x(the lp1 of single-fuse’
anticipated current beingl_p/n)
In the equation：Ip-total the stem-current climax value after paralleling n the fuse\s parallel quantity
1_p valid value of anticipated current
1_p1 stem-current climax value of single-fuse
l²t total：n x(the l²t value of single-fuse,anticipated current beingl_p/n)
Noted：the fuse’simple series-connection is banned from being used in the one-grade higher volt circuit