IEEE C62.62-2010 pdf download IEEE Standard Test Specifications for Surge- Protective Devices (SPDs) for Use on the Load Side of the Service Equipment in Low-Voltage ( 1000 V and . Less) AC Power Circuits
Consideration shall also be given to the possibility of ignition or explosion within the SPD. Where anexamination of the device indicates a likelihood of ignition, factors to be considered include the following:
The amount of combustible material likely to be involved initially
The probable rate of propagation
The consequences of such propagation, that is, the probability of extension beyond the SPDAppropriate precautions shall be taken to keep these factors within manageable limits. Precautions mayincludc suitable cxtinguishing agents in sufficient quantity, physical scparation from other combustibles, orother appropriate measures. In evaluating the possibility of explosion, consideration should be given tocomponent failure whenever hazardous materials are available in sufficient quantity to create an explosiveatmosphere.
All surge testing shall be conducted by technically qualified personnel who are aware of the hazards ofsuch testing. The voltage and current levels generally associated with surge testing are well above thoseconsidered lethal.Some considerations are the possibility of an accidental discharge of the surge gencrator.the consequences of a flashover to an unfavorable circuit, the possibility of a charge being trapped in theSPD, or the consequence of a violent component failure. Testing personnel should never stand in the line ofsight of components on printed circuit boards or panels with the enclosure open during SPD surge testingOn occasion, a component can unexpectedly fail in an explosive manner during surge testing. Fragments ofthe ruptured case and the component might cause injury to personnel in the vicinity. If visual observation isdesired, a suitable transparent barrier shall be provided
Surge testing of SPDs is best conducted only in an area dedicated solely to that purpose. The boundaries ofthe arca should be clcarly defined and appropriately marked. The surge test arca should be kept frce of allmaterials, meters, and test setups that are not associated with the surge test being conducted (see theexample in A.14). Where possible, the area should be isolated and equipped with electrical or mechanicalinterlocks, or both, on all entrances into the test arca and on removable barricr pancls. All metal fences andbarriers should be bonded to the grounding system. Consideration should be given to the possibility of thesurge flashing over to circuits or metallic parts that were not intended to be surged
When the SPD can be enclosed inquirements for installation are casiclto satisfv.This barrier may simplysutticient separationseparation from the tloor. whicfshould be presumed to contain conduit or other etal. Alternatively, the entire barrier may be made up ofphysical insulation. In cither casc, it should be complcte, cxcept where it is penetrated for inscrtion of inpuor output lines and measurements probes; and it must be able to provide adequate protection for a peavoltage equal to at least twice the peak of the incident test surge. (Circuits in breakdown at or near the surgtpeak can oscillate at high frequencies. Such oscillatory flashovers can thereby increase effective appliedpeaks by a factor approaching two.) Interlocks should be provided to minimize risks associated with accessbetween tests.
Capacitors in the test circuit or the device under test can retain a trapped charge. Suitable bleeders or shortcircuiting devices should be provided to protect the operator against any such trapped charge after passagof the test surge.
EMI from surge testing could conceivably cause malfunction of robots and other automatic equipment, andsuch equipment should be isolated from the immediate vicinity of surge testing operations.
The importance of conducting surge tests in a prudent manner cannot be overemphasized; safeguardingpersonnel has to be the prime consideration.