UPS Glossary - Series B - Batteries, Breakers, Boost charge, Brownout, Bypass, ...

Backup Power Supply
A power supply used to provide alternate system power in the event the primary power source fails or is unable to continue providing adequate system power.

Battery
One or more electrically connected cells of a device that transforms chemical energy into electrical energy.

Battery Back-up
1) The inverter/battery combination providing support to maintain function of selected output devices upon loss of commercial power.
2) Quantitatively, the calculated time duration this support is to be available.

Battery Charger
A device for changing alternating-current power to direct-current power for the purpose of charging a battery.

Battery Rack
A rigid support of one or more levels (tiers or steps) upon which a bank of stationary batteries are located. Also called a battery stand.

Battery Voltage
The total voltage between the positive and negative terminals of the battery. In lead-acid batteries the nominal open circuit voltage is stated to be 2volts per cell.

Bipolar
Having two poles, polarities or directions.

Bleeder Resistor
A resistor that allows a small current drain on a power source to discharge filter capacitors or to stabilize an output.

Blocking Diode
A device that prevents the flow of current from the UPS rectifier to the battery, but permits the flow of current from the battery to the UPS inverter.

Boost Charge
Charge, generally at high-rate, for a limited period to achieve full capacity in all cells of a battery.

Boost Transformer
May be an isolating transformer or an autotransformer that provides a means of raising a supply line voltage, usually by a small amount of 20% or less.

Break-Before-Make Switch
A switch which while transferring between two sources goes through a neutral position where momentarily neither source is connected to the output and an interruption occurs on the output.

Break-Before-Make Transfer
A transfer between two sources when a momentary break on the output occurs.

Break Transfer
As pertaining to a switch or static switch, transfer between two sources where the output momentarily loses continuity to either source and an interruption to the output voltage occurs.

Breakdown Voltage
1) The voltage level which causes insulation failure.
2) The reverse voltage at which a semiconductor device changes its conductance characteristics.

Breaker
A device designed to open and close a complete circuit by non-automatic means (like a switch), and to open the circuit automatically on a predetermined overload of current, without injury to itself.

Breaker-Automatic
A circuit protection device which will automatically open or break continuity

Bridge Circuit
Circuit with series-parallel groups of components.

Bridge Converter
A power conversion circuit with the active elements connected in a bridge configuration

Bridge Rectifier
Full-wave rectifier circuit employing two or more rectifiers in a bridge configuration.

Brownout
The condition created during peak usage periods when electric utility companies intentionally reduce their line voltage by approximately 10 to 15 percent to counter excessive demand.

Buck Transformer
A transformer that provides a means of lowering a supply line voltage, usually by a small amount such as 20% or less.

Bulk Capacitor
The energy storage capacitor at the front end of a regulator.

Bulk Voltage
The voltage across a bulk capacitor.

Bus
The common primary conductor of power from a power source to two or more separate circuits.

Bus Transfer Switch
Any switch (mechanical, electromechanical, or static) used to transfer a load from one source of AC supply power to another, often upon loss of power from the initial source.

Bypass
A path where the Commercial AC Power can be routed from the AC input to the AC output of an UPS, bypassing the Battery/inverter sections.

Bypass Source
See Alternate Source.

Bypass Transformer
A transformer that provides alternating current power to the UPS loads when the UPS equipment fails, is temporarily overloaded, or is out of service for maintenance.