Understanding SDS Means Passing Your Electrical Exam

To achieve a passing score on your electrical exam you need to understand what a SDS is. What is a SDS? It is an acronym for a separately derived system. Can you answer the following question:

Which of the following can be installed as a code approved (SDS) separately derived system:

I.    Power transformer

II.   On-site generator

III.  240v/120v 1? service

IV.  None of the above

Solution:

I, II & III only.

NFPA 70 defines a (SDS) separately derived system as: “An electrical source, other than a service, having no direct connection(s) to circuit conductors of any other electrical source other than those established by grounding and bonding connections.”

This definition identifies a SDS as an electrical source (other than a service) with no direct connection to the circuit conductors of any other electrical source, with the exception of those established by grounding and bonding connections. While a power transformer and on-site generator may be installed as a separately derived system, a service regardless of size or rating may not be installed as a SDS.

Knowing how to answer these kinds of exam questions is key to passing the electrical exam. Prepare for success. Click on the “Register Now” tab of call 888-919-3926 today.