![]() Whichever type of overcurrent protection is specified-fully rated or a combination-the specifier must start with an understanding of the difference between SCCR and IR. If current-limiting devices are not used, the only alternative is to design with “fully rated” components and overcurrent protective devices. Thus, the SCCR of the panel is the maximum RMS current at which the peak let-through current is safe for the most sensitive component. Specifiers achieve the proper SCCR by selecting a current-limiting device that limits the peak let-through current to a level that protects all components within the panel. If that SCCR depends on the use of a specific current-limiting device, then the equipment must be labeled as such, and indicate which device is needed. NEC Article 409 requires that the SCCR be displayed on industrial control panels. This applies to some so-called fully rated On new equipment, or where a series rating can be assigned by a registered professional engineer, it must be field marked on the end use equipment. NEC Article 240.86 has similar requirements. When replacements are needed, such breakers and fuses must be The NEC allows such combinations, but requires that their series rating be labeled on the equipment next to the IR. When this is done, the manufacturer’s datasheet will note that the IR is conditional on the combination of devices. The latter clear a circuit in less than one-half an AC cycle, limiting peak let-through current to a safe level. On the other hand, some manufacturers achieve higher IRs by having Underwriters Laboratories test their circuit breakers in series with current-limiting fuses or breakers. This is often referred to as “fully tested” or “fully rated.” Fuses have IRs that do not depend on the action of any other protective device in the circuit. This seems simple enough, but not all IRs are comparable. For example, if the calculated available fault current is 35 kA, then the IR and SCCR of all installed overcurrent protective devices and system components must be greater than 35 kA. To verify compliance with NEC 110.10, the circuit designer must calculate available fault current. This is due to the fact that SCCRs of an assembly take into account all components contained within the equipment rather than just the main overcurrent protective device. Usually, the SCCR of a system is much less than the maximum IR of the main overcurrent device. Fuses and circuit breakers must have sufficient IRs for the fault current they interrupt. But aįor proper protection and compliance with National Electrical Code (NEC) 110.10, the SCCR of equipment must be equal to or greater than the available short-circuit (or high-level ground fault) current where the equipment is installed. Precise positioning, precise temperature, rapid temperature rise, non-slip weight increase, digital display temperature, intelligent 15 minutes sleep, 183° three minutes extreme speed rise, fast stratification, safe disassembly, no damage to the motherboard.Specifiers often use the terms short-circuit current rating (SCCR) and interrupting rating (IR) interchangeably. iPhone X -14 Pro Max module + universal module + dot matrix module + follow-up unlimited upgrades.Ħ. Added countdown function, layering and fitting are more secureĥ. Newly upgraded heating element, fast heating, precise temperature controlĤ. Mijing iRepair MS1 Multi-function Desoldering Stationģ. iRepair MS1 pre-heating staion for iPhone X/XS/XS MAX/11/11Pro/11 Pro Max/12/12 mini/12Pro/12 Pro Max/13/13mini/13 Pro/13 Pro Max/14/14 Plus/14 Pro/14 Pro Max motherboard soldering separating.Ģ. iRepair MS1 desoldering preheating platform For iPhone X-14 Pro Max motherboard CPU IC heating disassembly and glue removal.ġ. ![]() Mijing iRepair MS1 Soldering heating Staion MS1-14 module for iPhone 14/14 Plus/14 Pro/14 Pro Max.
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