描述
有的熱繼電器有自動(dòng)復(fù)位功能,即熱繼電器動(dòng)作后電機(jī)停轉(zhuǎn),串接在主回路中的熱繼電器的熱元件冷卻,熱繼電器的觸點(diǎn)自動(dòng)恢復(fù)原狀。如果這種熱斷電器的常閉觸點(diǎn)仍然接在PLC的輸出回路,電機(jī)停轉(zhuǎn)后過(guò)一段時(shí)間會(huì)因熱繼電器的觸點(diǎn)恢復(fù)原狀而自動(dòng)重新運(yùn)轉(zhuǎn),可能會(huì)造成設(shè)備和人身事故。因此有自動(dòng)復(fù)位功能的熱繼電器的常閉觸點(diǎn)不能接在PLC的輸出回路,必須將它的觸點(diǎn)接在PLC的輸入端(可接常開觸點(diǎn)或常閉觸點(diǎn)),用梯形圖來(lái)實(shí)現(xiàn)電機(jī)的過(guò)載保護(hù)。如果用電子式電機(jī)過(guò)載保護(hù)器來(lái)代替熱繼電器,也應(yīng)注意它的復(fù)位方式。
GENERAL ELECTRIC DS3800NHVE1C1C USPP DS3800NHVE1C1C
General Electric DS3800NGRA1L1D Circuit Board NEW
General Electric DS3800NDID1M1D Drive Interface USED
General Electric DS3800DMPK1E1D PC Bored USED
GENERAL ELECTRIC DS3800HLNC1A1A NSPP DS3800HLNC1A1A
General Electric DS3800NEPA1E1D Excitor Board
GENERAL ELECTRIC DS3800HSCD1G USPP DS3800HSCD1G
GENERAL EL