search.noResults

search.searching

dataCollection.invalidEmail
note.createNoteMessage

search.noResults

search.searching

orderForm.title

orderForm.productCode
orderForm.description
orderForm.quantity
orderForm.itemPrice
orderForm.price
orderForm.totalPrice
orderForm.deliveryDetails.billingAddress
orderForm.deliveryDetails.deliveryAddress
orderForm.noItems
Test & measurement


Detecting risky residual currents using differential current measurement


R


esidual currents in low voltage networks represent a fundamental safety risk if they go undetected or if they are


detected too late. They may cause operations to be interrupted unexpectedly, incurring damage to man and machine and in the final instance, leading to high costs. “Detect early, warn and take action” are the watchwords in risk prevention. Permanent monitoring of residual currents is essential and is used to detect deterioration in the distribution system’s insulation in a timely manner. The residual current module for the


SINEAX AM/DM, LINAX PQ and CENTRAX CU series is being introduced by Camille Bauer to detect residual currents in electrical systems. It provides an RCM (Residual Current Monitoring) function as well as direct measurement of the ear th conductor currents in electrical systems. The RCM function is based on Kirchhoff's First Law (Junction Law). This rule states that in a junction in an electrical network, the sum of the incoming currents is equal to the sum of the currents leaving the junction. If there is a difference caused by leakage current flowing through the ear th, then a residual current is detected and repor ted. The operator is then requested to take action. The causes of residual current in a system can often originate in defective components, for example in switching power supplies (LED lighting, computers, photovoltaic rectifiers, rapid charge points, etc.), or defective insulation in electrical connections and devices, defective PEN connections, etc. Measurement of residual currents is


performed by residual current transformers. To provide this function, Camille Bauer has included residual current transformers to its product portfolio, in bushing-type and split-core


versions. An individual alarm threshold and early warning threshold can be defined for each residual current channel. When the alarm threshold is violated, or if the measurement (RCM) conductor is broken, this activates the device’s group alarm. Additionally, in devices with a data logger, all status changes are logged in the alarm log and early warning threshold violations are recorded in an event list. The alarm signal can be routed to digital outputs and displayed by the SMARTCOLLECT database software. The residual current values that are currently being measured can be visualised directly on the device display or on the device website (WebGUI) and can also be output on analogue outputs. The values can also be read via bus interfaces. By recording the average value of the


residual current, it is possible to detect a gradual change in the residual current. The advantages of permanent residual


current monitoring are evident. On the one hand, it can eliminate costly periodic manual inspections, which only indicate the status quo at the time of measurement. On the other hand, continuous monitoring improves fire protection and also makes a significant contribution to protection against personal injury and damage to proper ty. Applications for RCM, which is often in used in an energy metering and network quality analysis context, are frequently to be found in data centres, hospitals, hotels and other public buildings (for example shopping centres, airpor ts, etc.), industrial installations, sensitive production units, banks etc. In such cases, to avoid any safety risk, threshold values in compliance with EN 62020 are applied (for example 100 mA).


Camille Bauer www.camillebauer.com The residual current module lowers the safety risk in


electrical installations in low voltage networks and provides an early warning when gradual deviations occur.


60


January 2019 Instrumentation Monthly


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70  |  Page 71  |  Page 72  |  Page 73  |  Page 74  |  Page 75  |  Page 76  |  Page 77  |  Page 78  |  Page 79  |  Page 80