DCM305E Earth Leakage Clamp Features:
DCM305E TRMS Current Ranges:
DCM305E Display Hold Features
DCM305E Low Pass Filter:
DCM305E Compare Feature:
An earth leakage clamp, such as the Megger DCM305E, is generally a lightweight pocket size clamp meter designed to measure very small AC currents. They enable earth leakage faults to be detected and located without having to isolate and disconnect circuit wiring. In addition, most of these clamps are capable of performing AC current tests like any normal clamp meter. The measurement of earth leakage can be conducted on single or three phase systems.
RCD and RCBO operation
These two devices effectively monitor the currents flowing in the phase and neutral conductors. Under normal circumstances, these two conductors will have matching currents. An imbalance between the conductor currents will be detected by the RCD / RCBO sensing circuitry with the supply being disconnected by the RCD / RCBO. A similar principle is utilised when using an earth leakage clamp to detect / measure earth leakage. An imbalance between the phase and neutral currents = leakage current.
While it is possible to simply clamp the instrument around the earth conductor this procedure will only indicate leakage current present in the earth conductor. This may not offer a true indication of earth leakage in the entire installation.