Esboniad o y cais cwmpas a sgiliau swyddogaethol o clamp ammeters
Fel arfer, pan mesuriad cyfredol gyda a rheolaidd ammeter, mae'n angenrheidiol i torri i ffwrdd y cylched a stop cyn cysylltu y ammedr ar gyfer mesur. Mae hyn yn iawn problemus% 2c a weithiau arferol rhedeg moduron are nid ganiateir i gwneud. Yn Hyn pwynt, Defnyddio A Clamp Math Ammeter yn dod llawer Convenient, AS A CAN Mesur cyfredol heb torri y gylched. Clamp math ammeter
The gweithio egwyddor is fel dilyn:
Mae'r profi cylched gwifren pasio trwy'r haearn craidd yn dod y cynradd y presennol newidydd, lle y cyfredol yn yn y presennol yn y presennol. Felly% 2c y ammedr cysylltiedig i y yn mesurydd y cyfredol o y prawf cylched. Y clamp mesurydd gall fod newid newid gwahanol ystodau gan symud y y switsh. Fodd bynnag% 2c mae'n nid a ganiateir, i gweithredu gyda pŵer pan symud gerau. cywirdeb o clamp siâp gwylio yn yn gyffredinol uchel uchel% 2c fel arfer ranging o 2.5 i lefelau. Ar gyfer hawddfraint o defnydd, mae yn trosi switshis gyda gwahanol ystod gwahanol o cyfredol a foltedd swyddogaethau
Pithy fformiwla
Defnyddio a clamp ammedr i mesur bach AC cerrynt.
Mae'r inswleiddio gwifren o y profi llwyth yn clwyf o gwmpas y clamp haearn craidd.
Rhannu y darllen gan tro plws un i gael y gwir cyfredol gwerth.
explain
When checking whether the three-phase current of a small three-phase motor (less than 5 amperes) is balanced, if measured with a clamp type ammeter, the minimum head of the meter is 1-10 amperes, and some meters have a grid of 2 amperes. Less than 2 amperes or a few tenths of an ampere is even more difficult to measure. In addition, ammeters typically have significant errors at low ranges, making it difficult to read when the pointer is deflected. To accurately measure the current value, the load insulation wire can be wound 1 to N turns on the iron core of the ammeter clamp. Apply the principle of current transformer to enhance the magnetic field, thereby reading larger current values. This way, the reading is enlarged, but the true current value must be subtracted from the enlarged part. When adding one turn, divide the reading by 2; Divide by 3 when winding two turns. The rule is that the number of turns is N, the current is increased by N plus 1 times, and the current value is equal to the meter reading/(N plus 1). In addition, to eliminate the influence of residual magnetism in the iron core of the ammeter, if a large current is measured and a small current is measured immediately, the iron core of the ammeter should be opened and closed several times to eliminate residual magnetism in the iron core.
