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.
Reversal - The changing of the normal polarity of a battery due to overdischarge.
Inverter (off-line or stand-by) - UPS configuration in which the inverter is parallel-mounted to the load supply line and backs up the mains. This configuration offers a substantial cost reduction but is applicable only to low outputs, under 3 kVA, because it results in an interruption lasting up to 10 ms during transfer and does not filter inrush currents.
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.
Frequency Variation - A change in frequency of more than 3 Hz.
COS phil - A measure of the phase shift between the fundamental current wave and the fundamental voltage wave observed at the terminals of a non-linear load.
Top-Up Charge - A low rate charge following the main charge, designed to ensure maximum capacity.
