Quiz on the Code

Class 4 Circuits

1. Outputs of a Class 4 receiver and power outputs of Class 4 utilization equipment shall be considered a separately derived system if _______.
(a) the outputs are used as a supply for a feeder or branch circuit
(b) the output conductors do not terminate on overcurrent protective device(s)
(c) a separate EGC is connected to each circuit component and the load
(d) None of the above.

2. Class 4 power systems are permitted to be used in hazardous (classified) locations where _____.
(a) cables are installed in raceways listed for the hazardous location
(b) specifically permitted by other articles in this Code
(c) only Class 4 power cables occupy the same raceway as other Class 4 power cables
(d) specifically permitted by the AHJ

3. Conductors of one or more Class 4 circuits shall be permitted within the same cable assembly as conductors of Class 2, Class 3, or communications circuits if the insulation of the Class 2, Class 3, or communications circuit conductors in the cable is at least that required for Class 4 circuits.
(a) True
        (b) False
 
4. Based on Figure 726.121, the three components of a Class 4 circuit are _____.
(a) OCP, Class 4 Transmitter, and Class 4 power receiver
(b) OCP, Class 4 Transmitter, Class 4 power receiver, Utilization equipment 
(c) Class 4 Transmitter, Class 4 power receiver, Utilization equipment
(d) Class 4 Transmitter, Class 4 circuit, Class 4 power receiver

5. Regarding marking of Class 4 cables, which statement is true?
(a) Class 4 cable shall be rated for the intended ampacity shown by the marking FMP-XXA 
(b) Cables shall have a voltage rating of not less than 450 volts dc. Voltage ratings shall not be marked on the cables.
(c) AWG marking shall occur at least every 22.86 cm  (9”) on Class 4 cables
(d) Answer (a) & (b)

6. Class 4 power systems may not be installed in dwelling units.
(a) True
(b) False





Answers:
1. (a) 726.122
2. (b) 726.10
3. (a) 726.139(B)
4. (d) 726.121
5. (d) 726.144  &  722.179(A)(16)(3)
6. (a) 726.12