Glossary
- Ambient Noise/Electromagnetic Interference (EMI): Is an unwanted signal that is induced into the cable from external source (electrical cable, device, or nearby cable). Causes packet loss, lost connections, and network slowdown.
- Blackout: Extended zero voltage conditions caused by lightning, generator failure, transformer failure, and ground faults.
- Brownout: Long term under-voltage caused when peak demand exceeds generating capacity.
- Clamping Action Turn-On: Threshold voltage at which the suppression device starts to conduct or turn-on. Protection starts at this level; however true protection is specified by the maximum clamping voltage.
- Clamping Voltage: The Peak voltage appearing across the device when measured at conditions of specified pulse current amplitude and specified waveform.
- Crosstalk: Bleeds the signals from one wire pair to another pair. Causes slow transfer and blocks the transfer of data signals within the cable.
- EMI/RFI: (Electro Magnetic Interference / Radio Frequency Interference) Inductive or Radio Frequency electrical noise commonly occurring which can create erratic behavior in electronic circuits.
- EMI/RFI Noise Rejection: Most suppressors are poor filters of EMI/RFI noise. This is because if any filtering is added it is just a capacitor and then usually an inexpensive and ineffective one with high ESR value (Internal Impedance at RFI levels or poor dv/dt response).
- Failure Mode: The status of protected equipment in the unlikely event of a surge suppressor failure (due to surges of over-voltages beyond the suppressor's rated capability). Equipment can either be left operating but unprotected, or be removed from service (the suppressor will intentionally cause loss of power or signal by tripping/clearing a system breaker/fuse).
- Glitch: A transient over-voltage.
- Joule Rating: Peak energy rating at 10/1000us wave shape applied (along with rated rms. voltage) without causing device failure. The higher the joule rating the longer the expected life of the device. In some devices joule rating will affect clamping voltage performance.
- L-G: Line to Ground.
- L-N: Line to Neutral.
- L-L: Line to Line.
- Modes of Protection: Common mode means lines compared to ground. Normal (Differential) mode means across the lines.
- N-G: Neutral to Ground.
- Noise (electromagnetic interference or EMI): Unwanted signals (electrical signals other than the power line voltage) that negatively affect the circuits of sensitive electronic equipment in which they occur. Effects power, phone, and data lines and causes operation errors, data corruption, terminal lock-ups.
- Noise: Various high frequency impulses ranging from a few mill-Volts to several volts in amplitude.
- Operating Line Voltage: DC voltage or rms voltage normally expected to be applied to a device.
- Response Time: This has become a game among transient suppressor suppliers as A nano-second is several times faster than any transient commonly found in the real world. It is the time between the point at which the wave exceeds the clamping voltage level and the peak of the voltage overshoot.
- Sag: Short term under-voltage occurring when peak demand exceeds generating capacity sometimes caused by lightning when primary gas suppressors fire.
- Spike: A transient over-voltage.
- Suppression Voltage: The maximum peak voltage that will be seen across the active terminals of a suppressor at a specified waveform and source current. It is the "Let through" or remnant voltage the suppressor allows to be applied to protected equipment, a key criteria in performance specification.
- Surge: Transient over-voltage with a duration of less than 8.3 mS (one half cycle of the normal mains waveform).
- SVR (UL Suppressed Voltage Rating): Determined through testing by regulatory agency (UL, CSA, VDE, Etc.) or independent laboratory to specifications of IEEE/ANSI, IEC and UL. For permanently connected devices UL performs tests using a combination waveform 500 Amps/6000 volts.
- Transients (Spikes/Surges): Momentary voltage changes that bleed the signals from one wire pair to another pair. Causes slow transfer and blocks the transfer of data signals within the cable. Examples include lightning, downed power lines, power outage, construction disturbances, and power fluctuation.
- TVSS (Transient Voltage Surge Suppressor): A protective device used on electronic equipment to absorb transient energy entering the electronics through power, data, communication or ground lines.