NABCEP NEC Article 690 Applications 4

Question 1

NEC 690.71(A) covers storage batteries used with PV systems. What minimum voltage requirement applies to battery installations in dwelling units?

Accepted Answer

Battery systems must not exceed 50 V dc nominal

Answer

NEC 690.71(A) limits battery systems in dwelling units to 50 V dc nominal or less to reduce shock hazard in residential applications.

Question 2

Per NEC 690.74, battery interconnect conductors must be sized for at least what percentage of the rated ampacity required for the circuit?

Accepted Answer

125%

Answer

NEC 690.74 requires battery interconnect conductors to be sized at 125% of the maximum current for which the circuit is rated.

Question 3

According to NEC 690.72, what device is required to prevent overcharging of batteries in a PV system?

Accepted Answer

A charge controller or other approved current-limiting means

Answer

NEC 690.72 requires a listed charge controller or other approved means to prevent overcharging and potential battery damage or fire.

Question 4

NEC 690.10 sets maximum voltage limits for PV systems on one- and two-family dwellings. What is the maximum system voltage for these residential installations?

Accepted Answer

600 V dc

Answer

NEC 690.10 limits PV systems on one- and two-family dwellings to a maximum system voltage of 600 V dc.

Question 5

When an inverter is used in a PV system, NEC 690.60 requires that inverters listed for interactive operation must be listed and identified for use with which type of system?

Accepted Answer

Interactive (utility-interactive or grid-tied) systems

Answer

NEC 690.60 requires inverters for grid-tied applications to be listed and identified for utility-interactive operation to ensure safety and compatibility.

(NABCEP) Certified North American Board of Certified Energy Practitioners Specialist Practice Test

(NABCEP) Certified North American Board of Certified Energy Practitioners Specialist Practice Test

NABCEP NEC Article 690 Applications 4