class 2 and class 3

[edw]

Is a class 2 circuit still considered a class 2 circuit if the circuit is powered by an unregulated power source which typically runs within class 2 voltages, less then 30Vac and under 100 VA, but can go as high as 38Vac? Is this even a class 2 circuit? Is it ok to use class 2 rated cable for this circuit?

Appreciate any input.. Thanks

 

[hbiss]

Re: class 2 and class 3

A CL2 power supply is one that UL or other testing laboratory has determined to meet CL2 criteria. The supply will then display a label indicating that it is a CL2 supply and CL2 wiring methods can be used.

-Hal

 

[edw]

Re: class 2 and class 3

Is it ok to use CL2 Cable on an unregulated power supply capable of reaching 38 VAC?

 

[don_resqcapt19]

Re: class 2 and class 3

If the power suppy is not marked as a Class 2 power supply, then you must use Class 1 or Chapter 3 wiring methods.
Don

 

[ryan_618]

Re: class 2 and class 3

Take a look at 725.41

 

[edw]

Re: class 2 and class 3

If a device is rated for 24Vac +/- 20% and 24Vdc +/- 35% what is the correct cicuit class?

Class 2?
Class 3?

 

[don_resqcapt19]

Re: class 2 and class 3

If a device is rated for 24Vac +/- 20% and 24Vdc +/- 35% what is the correct cicuit class?

Class 1. It can't be Class 2 or 3 unless the power supply is listed and marked as a Class 2 or 3 power supply.
Don

 

[hbiss]

Re: class 2 and class 3

If a device is rated for 24Vac +/- 20% and 24Vdc +/- 35% what is the correct cicuit class?

That's not for us to determine. The device would be submitted to UL or other recognized testing laboratory and they will determine what specification it meets. They write the specs and while you could design to them (if you are a manufacturer) the device still would have to be submitted for testing and listing according to procedures.

If a device is not CL2 or CL3 listed as above then by default it is CL1 and must be wired using class 1 methods. So I guess the answer to your question is CL1.

-Hal

 

[edw]

Re: class 2 and class 3

Ok so is there a + or - to a class 2 or 3 power supply voltage which is accetable to a circuit and will not cross over to another class?

 

[tony_psuee]

Re: class 2 and class 3

edw,

Class 2 and 3 circuits are energy limited circuits. The tolerance of the power supply is not a factor in the circuit classification. You could have a listed Class 2 supply that is +/-50% or +/-5% and that will not change the classification of the circuit.

Tony

 

[edw]

Re: class 2 and class 3

Thank You all for the input, it's really nice to be able to get answers this fast.

All Hail Bill Gates

Regards
edw