GE DS3800HDDL1A1A数字量输入卡件
通过在所有3相周围连接钳式电流表来验证中性电流。如果中性电流不正确，检查S2系统设置\电流/电压配置中的设置，并检查CT接线。电流不平衡：显示电流不平衡的百分比。电流不平衡计算如下：I av=平均相电流=（I a+I b+I c）/3 I m=与Iav最大偏差的同相电流。即使使用上述公式可以实现大于100%的不平衡，PQM将不平衡读数限制为100%。如果平均电流低于CT PRIMARY设定点的10%，则不平衡读数强制为0%。这避免了系统负载较轻时的干扰报警。如果使用模拟电流，则不平衡不会强制为0%。Ia、Ib、Ic、In MINIMUM（最小值）：显示最小电流大小及其发生的时间和日期。该信息存储在非易失性存储器中，并在失去控制电源时保留
Verify neutral current by connecting a clamp-on ammeter around all 3 phases. If the neutral current appears incorrect, check the settings in S2 SYSTEM SETUP \ CURRENT/VOLTAGE CONFIGURATION and verify the CT wiring. CURRENT UNBALANCE: Displays the percentage of current unbalance. Current unbalance is calculated as: where:I av = average phase current = (I a + I b + I c)/3 I m = current in phase with maximum deviation from Iav, Even though it is possible to achieve unbalance greater than 100% with the above formula, the PQM limits unbalance readings to 100%.If the average current is below 10% of the CT PRIMARY setpoint, the unbalance reading is forced to 0%. This avoids nuisance alarms when the system is lightly loaded. If the simulation currents are being used, the unbalance is never forced to 0%. Ia, Ib, Ic, In MINIMUM: Displays the minimum current magnitudes and the time and date of their occurrence. This information is stored in non-volatile memory and is retained during loss of control power
