Tomi Engdahl’s ePanorama blog

DC voltage levels:

0.7V Nominal voltage drop on normal silicon diode or similar semiconductor junction

0.8V Voltages from 0V to 0.8V are considered to be logic 0 on TTL logic IC inputs

1.25V NiCd, NiMH battery cell nominal voltage

1.5V Carbon and alkaeline battery cell nominal voltage

1.6V The voltage you normally get from a fresh alkaeline battery cell

1.8V Quite commonly used very low voltage digital circuit operating voltage (many CPU cores)

2V Lead acid battery nominal cell voltage

2V Voltages from 2V to 5V are considered to be logic 1 in TTL logic IC inputs.

3V Lithium battery nominal voltage

3.3V LVTTL logic circuits operating voltage

3.6V Typical voltage used to power cell phones (either from NiMH or Li-Ion battery pack)

4.5V operating voltage for many small electronics gargets powered from three batteries

5V TTL logic circuits operating voltage

6V operating voltage for many small electronics gargets powered from four batteries

9V Commonly used battery voltage

10V Normal control voltage limit in 0-10V and 1-10V analogue control systems (light dimming and industrial use)

12V Car battery nominal voltage

13.8V the voltage you expect to get from car 12V power when car motor is running (charging battery)

24V Truck battery.
24V Automation systems most common nominal voltage used for logic signals and and current loop powering

24V common standard input voltages in Avionics and Defense applications

28V Maximum battery charging voltage for 24V battery system (for example batteries that power automation systems).

28V common standard input voltages in Avionics and Defense applications

36V Battery voltage used on some electric golf carts, electric scooters, electric bikes, high power cordless tools etc..

42.4V Voltages must be less than or equal to 42.4V peak/60V dc to meet safe limits and to be SELV.

42.4V Hazardous Voltage is a voltage exceeding 42.4V peak or 60V d.c., existing in a circuit which does not meet the requirements for either a Limited Current Circuit or a TNV Circuit.(IEC 60950)

48V Battery backed up -48V voltage is used on telecom systems for powering telephone exhanges and other telco equipment. The normal service voltage range for the -48 Vdc nominal supply at interface “A” shall be -40,5 Vdc to -57,0 Vdc according to ETSI EN 300 132-2

48V Some data centers use 48V DC to power servers (battery backup easy)

48V Phantom power feed for microphones in audio mixers most often uses +48V phantom power voltage
48V some automation systems use +48V power for equipment and I/O (electrical power distribution)

50V Work on energized circuits or apparatus below that voltage requires no “Hazard/Risk Evaluation.”     NFPA 7OE

60V Voltages must be less than or equal to 42.4V peak/60V dc to meet safe limits and to be SELV.

60V Hazardous Voltage is a voltage exceeding 42.4V peak or 60V d.c., existing in a circuit which does not meet the requirements for either a Limited Current Circuit or a TNV Circuit.(IEC 60950)

72V standard input voltage in rail applications

75V Low Voltage Directive is effective for voltages in range 50 – 1000 volts a.c. or between 75 and 1500 volts d.c

110V Seen on electrical power distribution control automation as IO voltage and for operating actuators on high voltage power distribution stations.

110V standard input voltage in rail applications

120V Extra-low voltage high limit is 120 V ripple-free d.c.

125V Commonly used insulation resistance testing voltage used for low voltage wiring testing where 250V test voltage is too much.

160V The highest DC voltage covered by the telephone/telecom/ITE industry is 160V (ANSI T1.311)

169V The peak voltage on 120V AC mains power is around 169V, you get around this voltage if you rectify and filter 120V mains power

220V Seen on electrical power distribution control automation as IO voltage and for operating actuators on high voltage power distribution stations.

250V Commonly used insulation resistance testing voltage. Tests on SELV and PELV circuits are carried out at 250 V.

270V common standard input voltages in Avionics and Defense applications

324V The peak voltage on 230V AC mains power is around 324V, you get around this voltage if you rectify and filter 230V mains power

380V DC power voltage for DC feed used on some data centers. Emerge Alliance pushes using this 380V system.

500V Commonly used insulation resistance testing voltage. Insulation tests at normal mains wiring (230V) is commonly tested with 500V test voltage. Minimum insulation resistance expected on mains circuit is 0.5 Mohm. Also test between SELV and PELV circuits and the live conductors of other circuits must be made at 500 V.

575V DC power voltage for DC feed used on some data centers

600V Voltage used on

750V Voltage used to power trains in Helsinki subway (third rail powering)    

1000V Commonly used insulation resistance testing voltage for circuits that operate above 500 V up to 1000 V.

1500V Low Voltage Directive is effective for voltages in range 50 – 1000 volts a.c. or between 75 and 1500 volts d.c

2500V Commonly used insulation resistance testing voltage

3250V Use 2300V rms or 3250V dc test voltage for dielectric-withstand test for double insulation

5000V Commonly used insulation resistance testing voltage when testing high voltage wiring

AC voltage levels:

0.316V The most common nominal level for consumer audio equipment is -10 dBV, 0.316 volts root mean square (VRMS).

0.7746V The reference voltage for the decibel unloaded (0 dBu) is the voltage required to produce 1 mW of power across a 600 ohms load (approximately 0.7746 VRMS)

1V  The reference voltage for the decibel volt (0 dBV) is 1 VRMS, which is the voltage required to produce 1 milliwatt of power across a 1 kilo-ohm load

1.228V The most common nominal level for professional equipment is 4 dBu. A signal at +4 dBu is equivalent to a sine wave signal with a peak amplitude of approximately 1.737 volts,or any general signal at approximately 1.228 VRMS.

12V A low voltage lighting system usually operates on 12 or 24 volts.

24V A low voltage lighting system usually operates on 12 or 24 volts.

24V Used for controlling relay coils in some automation and control systems.

50V Extra-low voltage high limit is 50V AC

50V Low Voltage Directive is effective for voltages in range 50 – 1000 volts a.c. or between 75 and 1500V DC

75V Typical telephone line ring voltage is 75 V a.c.(20 or 25 Hz), it could be between 40 and 150 Volts (15-68 Hz)

100V Mains voltage in Japan. Reference voltage level used on electrical power stations measurements (100V = nominal high voltage on line being measured)

110V Mains power in USA, the voltage you expect to get from mains outlet
115V Mains power in USA, the voltage you expect to get from mains outlet
120V Mains power in USA, the output voltage on the distribution transformer

200V If the voltage is less than 200 V, then the human skin is the main contributor to the impedance of the body in the case of a macroshock—the passing of current between two contact points on the skin.

208V The voltage you expect to get between two phases in USA in case our apartment
gets two phase wires from three phase transformer (208/120V)

220V Old European nominal voltage, harmonized to 230V

230V Electricity supplies within the European Union are now nominally 230 V ± 6% at 50 Hz

240V the voltage you expect get between two hots in USA on your hous
240V Old nominal mails voltage used in UK, harmonized to 230V
240V the voltage you get between two hots in USA on the distribution transformer

277V Voltage between phase and neutral on 277/480V three phase system, used in USA for example lighting loads on big buildings

400V Voltage between phases on 220/400V three phase system (old European system)

415V Voltage between phases on 230/415V three system (modern European system)

450V If the voltage is above 450–600 V, then dielectric breakdown of the skin occurs

480V Voltage between phases in USA in commonly used 3 phase distribution

600V Three phase power voltage

690V Three phase power voltage used in industry for larger electrical motors (Europe)

1000V Isolation test voltage for 130V rated working voltage basic isolation (IEC950)

1000V Low Voltage Directive is effective for voltages in range 50 – 1000 volts a.c. or between 75 and 1500 volts d.c
1000V There phase power voltage used on 1 kV power distribution (in use in Finland)

1350V Basic insulation of 1350V rms is needed for test-and-measurement instruments rated at 250V (IEC 61010-1)

1500V Basic insulation of 1500V rms is needed for information-technology products rated at 250V (IEC 60950-1)

1500V Isolation test voltage for 230V rated working voltage (IEC950) (basic isolation)

2100V Isolation test rating for reinforced isolation for 130V rated devices

2300V Use 2300V rms or 3250V dc test voltage for dielectric-withstand test for double insulation

7.2kV Common distribution voltage in USA

10kV Common distribution voltage in Finland

11kV Common distribution voltage in UK, New Zealand and Australia

12.47kV Common distribution voltage in USA

20kV Common distribution voltage in Finland

25kV Electrical trains use 25kV 50Hz power in Finland

33kV Common distribution voltage in UK, New Zealand and Australia

34.5kV Common distribution voltage in USA

110kV Commonly used voltage level on long distance electrical transportation lines

220kV Commonly used voltage level on long distance electrical transportation lines

400kV Commonly used voltage level on long distance electrical transportation lines