The basics of device circuit breakers | Standards and approvals
7.5 NEC Class 2
The NEC ( National Electric Code ) is the American standard that describes the safe installation of electrical cables and devices . The descriptions also include “ low power circuits ,” which are often also referred to as “ NEC Class 2 circuits ”. Circuits that conduct less than 100 VA are not considered hazardous to life and limb or liable to cause fires . Parts of UL 1310 are employed to test for NEC Class 2 approval .
This is obviously only useful on American territory ; however , NEC Class 2 is also widely accepted in the rest of the world . This gives machine builders and system manufacturers exporting to the USA an advantage .
For electrical equipment that is wired downstream from products with a NEC Class 2 approval , UL approval is not absolutely necessary ( Fig . 25 ).
NEC Class 2
+ + - - - Output DC 24V 10A |
|
|
U Out 29,5V
24V
13
14 Rem SGnd Out 1 Out 2
Signal
> 100 % Boost > 75 %
> 50 %
DC OK
|
1
2
3
4
|
CBMC |
1 2 3 4 13 14 1 2
IN - OUT +
1
2
IN +
|
QUINT POWER
NF C
Input AC 100-240V N / - L /+
PE
N L
Fig . 25 : Application example for circuit breakers with NEC Class 2 outputs
PhoENix CoNtACt 27