SK827100-AS交流接觸器模塊
DECS-100監(jiān)控感應(yīng)到的發(fā)電機(jī)輸出電壓，并在以下情況下采取保護(hù)措施：檢測(cè)到感測(cè)電壓。在以下條件下檢測(cè)到感測(cè)電壓的損失。
?感應(yīng)電壓小于額定電壓的50%（單相或三相感應(yīng)）。
?出現(xiàn)任何相位的總損耗（三相感應(yīng)）。
?任何相位（線對(duì)線）和三相平均值之間的電壓差超過20標(biāo)稱百分比（三相感應(yīng)）。
可通過BESTCOMS軟件調(diào)整0至25秒的時(shí)間延遲。這會(huì)延遲保護(hù)動(dòng)作，以便在不感應(yīng)B相發(fā)電機(jī)電流的應(yīng)用中允許磁場(chǎng)強(qiáng)制。這個(gè)默認(rèn)時(shí)間延遲設(shè)置為10秒。
BESTCOMS軟件允許選擇兩種保護(hù)措施中的一種，以防止傳感丟失。要么可以選擇完全關(guān)閉或切換到手動(dòng)模式。如果選擇停機(jī)且發(fā)生傳感丟失，則前部的發(fā)電機(jī)傳感丟失指示燈
面板和BESTCOMS燈中，繼電器輸出關(guān)閉，DECS-100在可調(diào)時(shí)間延遲到期。發(fā)電機(jī)感測(cè)丟失后DECS-100通電時(shí)停機(jī)時(shí)，發(fā)電機(jī)感應(yīng)指示燈將點(diǎn)亮5秒鐘。然而，如果損失傳感條件仍然存在，DECS-100在軟啟動(dòng)之前不會(huì)因傳感丟失而關(guān)閉時(shí)間延遲和感測(cè)時(shí)間延遲的丟失到期。
如果選擇了手動(dòng)切換，并且發(fā)生傳感丟失，繼電器輸出關(guān)閉，DECS-100在可調(diào)時(shí)間延遲到期后，轉(zhuǎn)換到手動(dòng)操作模式。
DECS-100將保持此操作模式
直到通過BESTCOMS切換。在選擇“轉(zhuǎn)移到手動(dòng)”之前，打開失去感測(cè)，需要確定適當(dāng)?shù)氖謩?dòng)（FCR）模式設(shè)定點(diǎn)水平不適當(dāng)?shù)膭?lì)磁水平可能導(dǎo)致設(shè)備嚴(yán)重?fù)p壞。
當(dāng)頻率降至12赫茲以下或發(fā)電機(jī)短路時(shí)，此功能將禁用檢測(cè)到條件。當(dāng)B相CT電流超過3時(shí)，確定發(fā)電機(jī)短路乘以每單位值。在軟啟動(dòng)時(shí)間內(nèi)，傳感關(guān)閉或傳輸丟失未激活。磁場(chǎng)過電壓（過勵(lì)磁停機(jī)）
現(xiàn)場(chǎng)過電壓條件可被配置（在BESTCOMS中）以關(guān)閉DECS-100繼電器輸出，禁用DECS-100，啟動(dòng)兩個(gè)動(dòng)作，或不啟動(dòng)任何動(dòng)作。當(dāng)場(chǎng)電壓增加時(shí)在10秒的固定持續(xù)時(shí)間內(nèi)，高于可調(diào)電壓電平設(shè)定值時(shí)，DECS-100啟動(dòng)所選操作。
如果DECS-100配置為關(guān)閉繼電器輸出，則磁場(chǎng)過電壓條件將點(diǎn)亮前部面板和BESTCOMS過勵(lì)磁停機(jī)指示器，并關(guān)閉端子AL1處的繼電器輸出和AL2。
如果DECS-100配置為硬件關(guān)機(jī)，則在10秒延時(shí)到期后，現(xiàn)場(chǎng)過電壓條件將禁用DECS100。當(dāng)DECS-100在現(xiàn)場(chǎng)后通電時(shí)
過電壓停機(jī)時(shí)，過勵(lì)磁停機(jī)指示燈將點(diǎn)亮5秒鐘。
The DECS-100 monitors the sensed generator output voltage and takes protective action if a loss of sensing voltage is detected. A loss of sensing voltage is detected during the following conditions. ? The sensed voltage is less than 50 percent of the rated voltage (one-phase or three-phase sensing). ? A total loss of any phase occurs (three-phase sensing). ? The voltage difference between any phase (line-to-line) and the three-phase average exceeds 20 percent of nominal (three-phase sensing). A time delay of 0 to 25 seconds is adjustable through BESTCOMS software. This delays the protective action in order to allow field forcing in applications that do not sense B-phase generator current. The default time delay setting is 10 seconds. BESTCOMS software allows the selection of one of two protective actions for a loss of sensing. Either a complete shutdown or a transfer to Manual mode may be selected. If shutdown is selected and a loss of sensing occurs, the Loss of Generator Sensing indicator on the front panel and in BESTCOMS lights, the relay output closes, and the DECS-100 shuts down after the adjustable time delay expires. When the DECS-100 is powered up following a loss of generator sensing shutdown, the Loss of Generator Sensing indicator will light for five seconds. However, if the loss of sensing conditions still exists, the DECS-100 will not shut down due to loss of sensing until the soft-start time delay and the loss of sensing time delay expires. If transfer to Manual is selected and a loss of sensing occurs, the relay output closes, and the DECS-100 transfers to the Manual mode of operation after the adjustable time delay expires. The DECS-100 will remain in this mode of operation until switched via BESTCOMS. Prior to selecting transfer to Manual on loss of sensing, it is necessary to determine an appropriate Manual (FCR) mode setpoint level to be transferred to. An inappropriate excitation level could result in severe damage to equipment. This function is disabled when the frequency decreases below 12 hertz or when a generator short circuit condition is detected. A generator short-circuit is determined when the B-phase CT current exceeds three times the per unit value. Loss of sensing shutdown or transfer is not active during the soft-start time. Field Overvoltage (Overexcitation Shutdown) A field overvoltage condition can be configured (in BESTCOMS) to close the DECS-100 relay output, disable the DECS-100, initiate both actions, or initiate neither action. When the field voltage increases above the adjustable voltage level setpoint for the fixed duration of 10 seconds, the DECS-100 initiates the selected action. If the DECS-100 is configured to close the relay output, a field overvoltage condition will light the front panel and BESTCOMS Overexcitation Shutdown indicator and close the relay output at terminals AL1 and AL2. If the DECS-100 is configured for hardware shutdown, a field overvoltage condition will disable the DECS100 after the 10 second time delay expires. When the DECS-100 is powered up following a field overvoltage shutdown, the Overexcitation Shutdown indicator will light for five seconds.
