Welcome to our comprehensive UPS Terminology Glossary. Whether you’re new to the world of IT, a seasoned professional looking to brush up on your knowledge, or someone curious about the complexities behind uninterrupted power supply, this glossary is for you. We’ve curated an extensive list of terms related to UPS systems, defined in an easily digestible manner. Dive in to explore and unravel the intriguing world of UPS terminology and enhance your understanding of these critical systems.
A
This refers to a small, unwanted residual periodic variation of the direct current (DC) output of a power supply which has been derived from an alternating current (AC) source.
A setup where multiple components are ready and running to keep a system operational even if one component fails.
A backup source of power that can be used if the primary power source fails.
A type of electrical current where the direction of the flow of electrons switches back and forth at regular intervals or cycles.
A unit that measures electrical current, or the amount of electrical charge that flows per second.
A unit of electric charge, with one ampere-hour representing the amount of electricity used in one hour at a steady current of one ampere.
A device that automatically switches from the main power to a backup power source when it detects a failure or irregularities in the main power.
The amount of time that a system, like a UPS, can operate using its battery as a power source.
In a data center context, this refers to the time a system or service is up and running, or available for use.
B
The duration a UPS system can provide power from its battery storage during a power outage.
A type of battery that recombines the hydrogen and oxygen gases generated during charging, minimizing water loss and reducing maintenance needs.
A battery that is mounted in tiers or layers, commonly seen in battery racks in a data center.
A type of battery that has vents to release gases produced during charging.
A group of battery cells connected together to increase the voltage or capacity.
The smallest unit of a battery that produces electricity from a chemical reaction.
A device that can interrupt high levels of electrical current flowing into the battery, protecting the battery from damage.
A configuration where batteries are placed on shelving units.
A total loss of power to an area.
A system that controls and monitors a building’s mechanical and electrical equipment such as ventilation, lighting, power systems, fire systems, and security systems.
A reduction in or restriction on the availability of power in a particular area.
A backup path for electrical current to flow in the event of a failure in the main path.
C
A system capacity that exactly meets the power demand of the load without any redundancies.
A device that pumps electrical energy into a battery.
A safety device designed to protect an electrical circuit from damage caused by an overload or a short circuit.
Measures that quantify the extent to which a system has excess capacity or redundancy to handle additional load or failures.
The ability of a material or device to conduct or transmit electricity.
A term referring to the power factor of a system, indicating the phase difference between voltage and current.
This usually refers to the power factor under full load conditions.
The ratio of the peak value to the effective value of a waveform, often used in relation to current and voltage waveforms in power systems.
These are systems, machines, or operations that must stay operational, and can’t afford a power failure.
The flow of electrical charge, usually measured in amperes (A).
The initial surge of current seen when an electrical device is first turned on.
Distortions in the electrical current waveform, often due to non-linear loads.
The maximum current that a circuit or device can handle safely.
A method of signal transmission that uses a consistent current, often 20 milliamperes, as a signal in a closed loop circuit.
D
This occurs when a battery is discharged to a significant degree, often reducing its lifespan and performance.
A temporary drop in the voltage level.
An electric current flowing in one direction only.
The speed at which a battery loses power, usually measured in amps.
This refers to the distortion in a power system caused by a single harmonic frequency.
Total distortion includes all harmonic distortions and not just a single harmonic.
A type of UPS system where power is continuously converted from AC to DC and back to AC. It provides a clean, no-break power supply.
The efficiency of a double conversion UPS system, factoring in losses from the continuous conversion process.
E
The ability of an electrical device to operate effectively without causing electromagnetic interference to other devices.
A sensor that monitors environmental conditions, such as temperature and humidity, in a data center.
A separate module that provides additional battery backup capacity to a UPS system.
F
A filter that changes the phase of signal components relative to each other.
A method of maintaining a battery at full charge by applying a constant voltage.
The voltage at which a battery is maintained during float charging to keep it at full charge.
A mathematical concept used in signal processing to break down a complex waveform into a set of simple sine waves.
A device that converts the frequency of an alternating current (AC).
G
A design technique that separates electrical circuits to eliminate stray currents. It’s used for safety and data integrity.
A machine that converts mechanical energy into electrical energy.
H
A component of a waveform that is a multiple of the fundamental frequency.
Noise or interference in a signal due to high-frequency components.
The ability to replace or add components such as batteries while the system is running without disruption.
I
A component of a waveform that is a multiple of the fundamental frequency.
Noise or interference in a signal due to high-frequency components.
Noise or interference in a signal due to high-frequency components.
A device that converts direct current (DC) into alternating current (AC).
A type of inverter that operates only when the main power supply fails.
An inverter that is always in operation, continuously converting DC to AC power.
In electrical systems, it refers to the separation of electrical circuits to prevent the flow of electricity from one circuit to another, enhancing safety.
J
K
A unit used to measure the apparent power in an electrical circuit, which represents the total power used in the circuit.
L
A common type of battery that uses a reaction between lead, lead peroxide, and sulfuric acid to store and release electrical energy.
A type of uninterruptible power supply that can regulate low voltages (brownouts) and over voltages (power surges) without resorting to battery power.
A type of rechargeable battery commonly used in electronics due to its high energy efficiency and long life.
Electrical loads where voltage and current waveforms are in phase and follow a linear relationship.
Electrical loads where the current waveform is not a linear function of the voltage waveform, often creating harmonics.
The practice of intentionally shutting off power to certain parts of a power system to avoid a total system failure when demand is too high.
The amount of electrical power consumed by a device or system under normal operating conditions.
M
A switch that allows power to flow around the UPS, facilitating maintenance work without interrupting power to the load.
An interface card that enables communication between devices using the Modbus protocol, often used in automation systems.
A single, separately functioning part of a system.
A measure of reliability, indicating the average time between system or component failures.
The average time that a non-repairable system operates before failure.
The average time taken to repair a failed component or system.
N
Unwanted electrical or electromagnetic energy that degrades the quality of signals and data.
The intensity of unwanted sound or electrical disturbance.
An electrical load that distorts the waveform of the current drawn from the source.
O
A type of inverter that switches on to provide power only when the main power source fails.
A type of UPS system that is on standby, switching to battery power only when a power outage occurs.
A type of UPS that constantly provides battery-backed power to devices, protecting them from all types of power disturbances.
Interruptions to the power supply.
The maximum amount of power that a device can produce under normal conditions.
The total distortion caused by all harmonics in a power system.
P
The current load as a percentage of the rated load capacity.
A filter used to change the phase angle of certain frequencies in a signal.
The ratio of real power (watts) to apparent power (volt-amps), used to measure how effectively electric power is being used.
Usually refers to the power factor under a specified load condition.
Also known as a backup power source, it’s an alternative source of electrical power in case of failure of the main power source.
A technique for controlling the amount of power delivered to an electronic device by changing the duty cycle of a digital signal.
Q
R
Referring to devices designed to be installed in a standard rack system.
The specified maximum output a system or component is designed to deliver.
A measure of the generator’s response to sudden load changes, often used in short-circuit and transient stability studies.
A type of battery that recombines the hydrogen and oxygen gases generated during charging back into water, reducing maintenance needs.
A device that converts AC to DC (rectification) and can also charge batteries.
The practice of duplicating critical components or functions in a system to increase its reliability.
A configuration where the redundant components are only activated when the primary ones fail.
The ability of a system to perform its required functions under stated conditions for a specified period of time.
This is the duration that a battery can keep supplying power during a power outage.
A standard for serial binary data signals connecting between a DTE (Data Terminal Equipment) and a DCE (Data Circuit-terminating Equipment).
A standard for digital data transmission that uses balanced, or differential, signals.
A standard for serial communication transmission of data that supports multiple devices on the same data line.
The duration for which a UPS system can provide power from the batteries during a power outage.
S
The process of setting up equipment and systems in a way that minimizes risks to human health and safety.
A power source that has safety measures in place to protect against electrical faults and provide a reliable power supply.
The capability of a system to handle a growing amount of work, or its potential to be enlarged to accommodate growth.
A standard protocol used to manage and monitor network devices.
A type of UPS that remains idle until a power loss occurs, at which point it switches from utility power to its own power source.
A switch that allows the UPS to be bypassed in the event of a UPS malfunction, allowing power to flow directly from the input to the output.
A measure of a generator’s impedance under a sub transient condition, used in short-circuit studies.
A sudden increase in voltage, which can cause damage to electronic devices if not regulated.
T
The measure of the distortion of an electrical signal due to harmonic frequencies.
A situation where an increase in temperature causes conditions to change, leading to further temperature increase, potentially leading to catastrophic failure.
A method of simplifying complex electrical circuits for analysis.
A type of power system where three circuit conductors carry three alternating currents that reach their peak values at different times.
The percentage of variance in a specified parameter that will still allow an electrical component to function correctly.
An electrical device that can change the voltage of an alternating current.
A measure of the voltage drop in a transformer under full-load short-circuit conditions, relative to the rated voltage.
U
A global safety certification company that tests products to verify they meet specific safety standards.
A system where multiple UPS units operate in parallel, with one or more acting as a backup in case the primary unit fails.
A system where multiple UPS units operate in parallel to share the load, but there is no backup unit if one fails.
A device that provides battery backup when the electrical power falls to an inadequate voltage, or fails completely.
V
A type of battery where gases produced during charging are vented to the atmosphere.
The unit of electrical potential difference, or the ‘force’ that drives electrical energy.
The voltage at which a battery is maintained after being fully charged to maintain that capacity by compensating for self-discharge.
A type of lead-acid battery where the amount of gas released during charging is regulated by a valve, and any escaping gas is converted back into water.
A device that provides battery backup when the electrical power falls to an inadequate voltage, or fails completely.
