Appendix D - Inverter/Charger Terminology - Sensata Magnum Energy MS Series Owner's Manual

Appendix D – Inverter/Charger Terminology
Appendix D – Inverter/Charger Terminology
The following is a glossary of terms with which you may not be familiar. They appear in the
various descriptions of inverter and battery charger operation.
Absorption Stage – In this second stage of three stage charging, the batteries are held at a
constant voltage (the absorb voltage setting) and the battery is charged to its maximum capacity.
AC (Alternating Current) – Electrical current that varies with time (i.e., utility power). The rate
at which the voltage changes polarity is the frequency in Hertz (Hz).
Ampacity – The ampacity of a wire is its current carrying capacity with reference to the cross-
sectional area of the conductors, the temperature rating of the insulation and the ambient
temperature.
Automatic Transfer Relay (inside the inverter) – An automatic switch that switches between
Inverter and Standby mode depending on availability of AC input power. If AC is present, the unit
will be a battery charger and pass power through the inverter. When the AC goes away, the unit
becomes an inverter.
Bulk Charge Stage – The fi rst stage in three stage charging. In this stage, a constant current is
fed to the batteries and as they accept the current the battery voltage will rise.
CEC (Canadian Electrical Code) – The guidelines and acceptable practices for electrical
installations in Canada.
Current (Amps) – The amount of electricity fl owing through a conductor.
DC (Direct Current) – Electrical current that does not vary with time (i.e., battery voltage).
Deep Cycle – A deep cycle occurs when a battery is discharged to less than 20% of its capacity
(80% depth-of-discharge).
Deep Cycle Battery – A battery designed to be routinely discharged to 20% of its maximum
capacity without damage. This type of battery is recommended for use with an inverter system.
Derating – As an inverter (or charger) is used above its normal temperature, it's capacity to
power loads (or charge) continuously is decreased.
Digital Volt Meter (DVM):
True RMS – A voltmeter that incorporates a RMS converter to read true RMS for any waveform
shape.
Averaging Type – A voltmeter that requires a sine wave waveform shape to provide an
accurate reading.
Effi ciency – Usually given as a percentage, effi ciency is the ratio of the output to the input. The
effi ciency changes with power output levels of any inverter.
Electrolyte – Typically a mixture of water and sulfuric acid that is used in lead-acid batteries; it
is commonly referred to as battery acid.
Equalization – Controlled "overcharging" of the battery causing it to bubble and mix. This helps
reduce stratifi cation.
Float Stage – During the third stage of three stage charging, the voltage and current are
reduced to a level that will trickle charge or maintenance charge the battery. This assures the
battery remains fully charged even while sitting.
Fuse or Disconnect – When current exceeds a preset limit the fuse or disconnect will fail before
the wiring or equipment it is protecting. Disconnects are also called circuit breakers. These are
usually reset and can act as a switch to turn off power to equipment for servicing.
Grid (The grid) – Also called the utility grid, this refers to the public power distribution system.
Impedance – Slows the electrical fl ow of Alternating Current (AC).
LED (Light Emitting Diode) – A light made up of semi-conducting material.
Line Tie – Term used when the inverter is connected to public power or to the "grid" system.
Load(s) – An electrical item that draws power (i.e., lights, radio, refrigerator, etc.) to work.
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