Intermittent Test - A test during which a battery is subjected to alternate periods of discharge and rest according to a specified discharge regime.
Internal Impedance - The opposition exhibited by a circuit element (cell or battery) to the flow of an alternating current (a.c.) of a particular frequency as a result of resistance, induction and capacitance.
Critical Load - Devices and equipment whose failure to operate satisfactorily jeopardizes the health or safety or personnel and/or results in loss of function, financial loss, or damage to property deemed critical by the user.
Transformer short-circuit voltage (Uscx %) - Relative measurement (%) of the internal impedance of a transformer. This short-circuit impedance is commonly called the short-circuit voltage because it is measured during a short-circuit test (shorted secondary winding subjected to a current set to In). For most common three-phase transformers, this value ranges between 3 and 6%.
Earthing system IT - Earthing system in which the neutral is isolated from the earth or connected to the earth via a high impedance and the various exposed conductive parts are connected to the earth via individual earthing circuits. An alarm must signal the appearance of a first insulation fault. The installation must be de-energized immediately in the event of a second insulation fault.
End Voltage (also see Cutoff Voltage) - The prescribed voltage at which the discharge (or charge, if end-of-charge voltage) of a battery may be considered complete.
Open-Circuit Voltage (OCV) - The difference in potential between the terminals of a cell when the circuit is open (no-load condition).
