First of all, from the appearance point of view, the shell of the heat-shrinkable tube SPD is using a section of heat-shrinkable tube which wrapped the electronic components tightly after high temperature heating, thus forming the shell of the finished lightning protection device.
Secondly, from the structural point of view, the inner place of the heat shrinkable tube SPD is not suitable to be installed a safety trip protection device. Because heat-shrinkable tubes need high-temperature processing to shrink, but high-temperature processing can cause damage to the safety trip protection device, therefore,heat-shrinkable tube SPD are not suitable for series-type lightning arresters.
Third, as far as safety performance’s concerned, if the lightning arrester is broken down by lightning, there is a high probability that the surge arrester will catch fire, because the flame retardant effect of the heat shrinkable tube is not very good, and there is no safety trip protection device inside the surge. If the surge arrester get fire, it will cause damage to the driver and the light board of light finally.
However, the potting type SPD has larger internal space and does not require high-temperature processing. Therefore, not only can a safety trip protection device be installed inside it, but also a working status indicator can be installed according to customer’s requirements. In the meantime, the potting glue can wrap the electronic components tightly after the potting is completed, which isolates the original device from the air effectively. At this time, as long as the selected potting glue is fireproof and flame retardant, and the shell is also made of fire-retardant materials, the lightning arrester will not catch fire even if it is hit by lightning, so that it can protect the driver and the light board effectively.
Finally, from the cost point of view, the cost of potted SPD is higher than the cost of heat-shrinkable tube SPD, and this may be the only disadvantage of potted SPD.
The SPD produced by Shenzhen Greenway Electronic Co., Ltd. has always adopted the attitude of "quality without compromise". Our company has always insist in using flame-retardant plastic materials to make the shell, and always insist in using standard flame-retardant potting glue for manufacturing. Variety of products of Shenzhen Greenway Electronic Co., Ltd has obtained TUV and CE certification from South Germany, ETL certification from America, and CQC certification from China.
Fig. 1 Sealing type spd
Fig. 2 Heat shrink tube type SPD