Clas 1,2,3 diference ?
- Thread starter relbas
- Start date
- Status
- Location
- Logan, Utah
Take a look at the definitions of each of the classes in 725.2.
Basically it is the power supply that will define what class of circuit you will have. Such as a Class 2 transformer for a door bell system.
Chris
Basically it is the power supply that will define what class of circuit you will have. Such as a Class 2 transformer for a door bell system.
Chris
hbiss
EC, New York NEC: 2017
- Location
- Little Falls, New York NEC: 2017
- Occupation
- EC
Yes it is confusing and you are not the only one. Basically that has all been done away with as far as we electricians are concerned. That testing is done by a testing laboratory such as UL as part of the listing process. The low voltage transformer, power supply or anything that supplies low voltage (except batteries) will have the required class of wiring indicated on it's listing label. If it doesn't it probably predates this requirement, so your choices are to either replace it or consider it class 1.
-Hal
-Hal
ryan_618
Senior Member
- Location
- Salt Lake City, Utah
Take a look at Table 11. A Class 2 circuit is considered safe from fire and from shock. A Class 3 circuit is considered safe from fire, but not from shock. A Class 1 circuit is not safe from either.
Notice, for example, that you can have high voltages for Class 2, but the power would be limited to 1/2 watt...safe from fire and from shock.
Notice, for example, that you can have high voltages for Class 2, but the power would be limited to 1/2 watt...safe from fire and from shock.
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