What is HV,MV and LV

[vinod]

Kindly define the voltage range of High Volt (HV), Medium Volt(MV) and Low volt (LV)?

 

[Dennis Alwon]

Kindly define the voltage range of High Volt (HV), Medium Volt(MV) and Low volt (LV)?

There really is no definition of those terms. Low voltage can mean 24 volts if you are referencing 120 volts ot it can be 240 volts if your reference for high volts is 480.

The NEC does not define it. What are you specifically looking for.

The NEC oftens has articles that refer to 600 volts or less and others that say over 600 volts but that is not a definition of voltages.

 

[vinod]

range

range

As far as I know that,

LV is <600V
MV is >600V to <38KV
HV is >38KV to <115 KV
Extra HV is >115KV

Am I correct?

 

[Dennis Alwon]

As far as I know that,

LV is <600V
MV is >600V to <38KV
HV is >38KV to <115 KV
Extra HV is >115KV

Am I correct?

Where, may I ask, are you referencing this info from?

 

[Dennis Alwon]

This is from Wikkipedia

In electric power transmission engineering, high voltage is usually considered any voltage over approximately 35,000 volts. This is a classification based on the design of apparatus and insulation.
The International Electrotechnical Commission and its national counterparts (IET, IEEE, VDE, etc.) define high voltage circuits as those with more than 1000 V for alternating current and at least 1500 V for direct current, and distinguish it from low voltage (50?1000 V AC or 120?1500 V DC) and extra low voltage (<50 V AC or <120 V DC) circuits. This is in the context of the safety of electrical apparatus.
In the United States 2005 National Electrical Code (NEC), high voltage is any voltage over 600 V (article 490.2). Laypersons may consider household mains circuits (100?250 V AC), which carry the highest and most dangerous voltages they normally encounter, to be high voltage. For example, an installer of heating, ventilation and air conditioning equipment may be licensed to install 24 Volt control circuits, but may not be permitted to connect the 240 volt power circuits of the equipment.
Voltages over approximately 50 volts can usually cause dangerous amounts of current to flow through a human being touching two points of a circuit, so safety standards generally are more restrictive where the chance of contact with such high voltage circuits exists.
In digital electronics, a high voltage is the one that represents a logic 1 (1.1?5 V).

 

[vinod]

Sir
Thank you very much for your explenation.
I am working as a electrical substation technician.

 

[zog]

Per IEEE:

LV < 600V
MV 601-69kV
HV 69kV-230kV
EHV 230kV- 800kV
UHV >800kV

 

[vinod]

Thank you Sir

This is what I am really looking for....

Thanks a lot.... Mr.Zog

 

[weressl]

Kindly define the voltage range of High Volt (HV), Medium Volt(MV) and Low volt (LV)?

It is best to go to an authorotive source. (Wikipedia may be right but it is NOT and authority.)

IEEE Std. 141 also known as the Red Book
120-600V Lov Voltage
2400-69000 Medium Voltage
115000-230000 High Voltage
345000-765000 Extra High Voltage

(This way you can cite the authority, not Jack from the Mike Holt Forum....)

 

[dbuckley]

Funny that; IEEE is an international authority, but the 110KV lines we have here in NZ dont fit into any official category....

 

[zog]

Yes they do, they are HV. Lazlo quoted the common voltage ratings of the equipment per IEEE.

 

[Dennis Alwon]

It is best to go to an authorotive source. (Wikipedia may be right but it is NOT and authority.)

IEEE Std. 141 also known as the Red Book
120-600V Lov Voltage
2400-69000 Medium Voltage
115000-230000 High Voltage
345000-765000 Extra High Voltage

(This way you can cite the authority, not Jack from the Mike Holt Forum....)

I was not quoting Wikipedia as an authority but more to make my point that the NEC does not have a definition of high voltages, etc. It just supported what I said in the the voltage is relative to what you are working on.

Where does 24Volts fit in with IEEE--- extra Low voltage????

 

[weressl]

Where does 24Volts fit in with IEEE--- extra Low voltage????

It's outsdie of the Electrical Engineers realm.......

 

[360Youth]

My understanding was:

<60v = LV
60-600 = MV
>600v = HV

I'm not quite sure about the separator between LV an MV, but that was always how I understood it. Except for the fact that there is no real NEC defintion, it looks like I am way off from the norm.

 

[sreeja]

Is it internationally accepted range?

 

[weressl]

Is it internationally accepted range?

Nothing is.

It would also be helpful if you were to "quote" the original posting so we know which one of the voltage ranges is your question about.

 

[coulter]

...the 110KV lines we have here in NZ dont fit into any official category....

Doesn't that have something to do with the coriolis effect and positive electron spin?:roll:

carl

 

[brian john]

Then on the lighter side there is the control tech Definition, anything above 24 VAV is HV......