It is unfortunate, but a fact of life, that computers, computer related products, process control and data communications equipment can be damaged by high-voltage surges and spikes. Such power surges and spikes are most often caused by lightning strikes but can also be caused by power cuts, for example load shedding. A lot can be done as far as protection is concerned. However, it is best to begin by describing the magnitude of the threat from which you need protection. The first stroke of lightning during a thunderstorm can produce peak currents ranging from 1,000 to 100,000 Amperes with rise times of 1 microsecond. It is hard to conceive of, let alone protect against, such enormous magnitudes. Fortunately, such threats only apply to direct hits on overhead lines. Hopefully, this is a rare phenomenon. More common is the induced surge on a buried cable. When lightning hits the ground, it creates a ripple effect such as when a drop falls into water. These ripples can travel up to 5km through buried cable and can damage unprotected equipment. Another cause of damage to equipment comes from power cuts or power surges. This can be described by viewing electricity like a river, flowing into different channels. When a channel is closed, the water must still go somewhere causing some of the other channels to reach peak levels. Computer equipment has often been damaged by lightning, not because of the absence of a protection device, but because inadequate attention was paid to grounding. Good quality ground connection cannot be emphasized enough. Conceptually, lightning protection devices are switched to ground. Once a threatening surge is detected, a lightning protection device grounds the incoming signal connection point of the equipment being protected. Thus, redirecting the threatening surge on a path-of-least-resistance (impedance) to ground where it is absorbed. When providing surge protection for a building, there are three components that need protection: In the server room cabinet, it is necessary to install either the Netshield NLMAINLITE-2U-E, NLPROCLITE-2U-E or NLEDU-PROCxx-1U depending on the need of the user: Basic entry level Class I & II surge protection for cabinets: NLEDU-PROC16-1U or NLEDU-PROC32-1U Basic Entry Level Cabinet Lightning and Surge Arrestors High entry level Class I & II surge protection for cabinets: NLMAINLITE-2U-E and NLPROCLITE-2U-E High Entry Level Cabinet Lightning and Surge Arrestors
Top level Intelligent cabinet controller with Class I & II surge protection NLMNDBLT1P-2U32 Distribution and NLMNDBNT3P-3U32 Core Cabinet Controllers Questions to raise before an inquiry If all these questions are “NO” you can inquire on the entry level surge protection units If there is a “YES” at first question inquire on NLMAINLITE-2U-E If there is a “NO” to question 1 but a “YES” with one of the other two questions inquire on NLPROCLITE-2U-E .
350/NLFC3S350, depending on whether 1-phase or 3-phase power is used. In case of a strike the trip switch will trip and will not be able to be reset again before the blown fuse, indicated by a red LED light, is replaced with a (NLRF350ST/NLRFN350ST). This ensures that no strike will go unnoticed and that the equipment might be left unprotected for only a short period of time, until the fuse in question has been replaced.
