Of detector of electric fire monitoring define

National level GB14287-2005 " electric fire supervisory system " of the first part 3.3 in, "Detector of electric fire monitoring " (Detectorsforelectricfireprotection) be defined to be: "Explore be waited for by the odd electric current in protective route, temperature the detector that parameter of electric fire hazard changes " .

GB14287-2005 regulation: Detector of electric fire monitoring has with exploring parameter to distinguish " type of odd electric current is electric fire monitoring detector " (GB14287-2005 the 2nd part) and " measure Wen Shi detector of electric fire monitoring " (GB14287-2005 the 3rd part) two kinds; Distinguish with working way have independent type detector (the detector that has monitoring warning function) with detector of blame independence type two kinds.

Visible, odd electric current and temperature are considered as the key that electric fire technology is on guard in GB14287-2005. In fact, short circuit of sex of ground connection electric arc, equipment or join dot temperature are exorbitant it is the main reason that electric fire produces.

Be based on the definition of detector of electric fire monitoring, the task of detector of electric fire monitoring depends on type of odd electric current only be on guard electric fire, as normative as GB16917-1997 place RCBO (breaker of movement of odd electric current, namely " switch of leakage of electricity " ) in defend parameter of function, technology, structure asks to wait for a respect to have very big distinction. RCBO more side overweight person defends safely. Both ought to cooperate to use, but cannot replace each other.

Defend to the metric monitoring of parameter of electric power of etc of electric current, voltage and breakdown, existing electrical engineering parts of an apparatus is very mature already. These functions are added on detector of electric fire monitoring (for example GB50045-94 (2005 edition) " expensive plan " " cross electric current to explore " ) , the author thinks is expansibility only, be not necessary. Of course, if the user closes to need to had had electric current, unusual voltage to call the police at the same time really in certain field, should not talk additionally again.

A few concepts related

Discussing form of odd electric current before the setting of detector of electric fire monitoring, be necessary to make clear first the following concept:

"Odd electric current " : Line of look of circuitry of communication power supply (La, Lb, Lc) the vector of the electric current with neuter line N and. When producing breakdown of single-phase ground connection, no matter three-phase load is balanced, the theoretical value that this vector mixes is 0 (still existing actually the normal leak electric current of circuit and equipment) ; When producing ground connection breakdown, the vector that odd electric current is ground connection fault current and normal discharge leakage current and.
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