Blackout - A zero voltage condition lasting for more than two cycles. Same as a power failure
Voltage-Keyed - A system which incorporates a mechanical identifier on batteries and devices to ensure only batteries of the correct voltage are connected to the device.
RS485 (Recommended standard RS485) - This standard is similar to RS422A except that the number of possible links is greater and up to 32 senders may be interconnected to as many receivers. This system is particularly designed for local-area networks.
Earthing system TT - Earthing system in which the neutral and the exposed conductive parts are directly earthed. The installation must be de-energized immediately in the event of an insulation fault.
Cubicle (parallel UPS unit) - Cubicle containing a rectifier/charger and an inverter. It is connected to one or several other identical cubicles and a bypass cubicle to make up a parallel UPS.
Dry Cell - A cell with immobilized electrolyte. The term "dry cell" is often used to describe the Leclanche cell.
Reliability - Probability that a device will accomplish a required function under given conditions over a given period of time. Rms value of AC current with harmonics The rms value Yrms of a non-sinusoidal alternating current may be determined on the basis of the individual harmonic currents - where Y is the rms value of the fundamental.
