Three-part communication shows up on the NERC RC exam constantly, and it trips up candidates who assume it's a "soft skill" question rather than a standards question. It isn't. COM-002-4 (Operating Personnel Communications Protocols) and COM-003-2 (Three-Part Communication for System Operators) set specific, testable requirements for how directives get issued, repeated back, and confirmed — and the exam will hand you scenario questions built to catch operators who skip a step under pressure.
Test Tips
- Know the difference between a reliability directive and routine dialogue. COM-002-4 applies to Reliability Directives, Operating Instructions that are reliability directives, and their repeat-backs — not every radio call needs the full three-part protocol. The exam likes to test whether you can tell the two apart.
- Memorize the three steps in order. (1) The issuer states the instruction. (2) The receiver repeats it back. (3) The issuer confirms the repeat-back was correct — or corrects it and the receiver repeats back again until it's right. If a question skips step 3 (issuer confirmation), that's the wrong answer.
- Watch for the "close enough" trap. A repeat-back that's paraphrased or approximate does not satisfy the standard. If the exam shows a repeat-back that changes a number, a device name, or a timing element, the correct answer is that the issuer must correct it before the instruction is considered acknowledged.
- Language matters — English is the default, and alternate language protocols must be pre-established. COM-003-2 requires entities to identify in advance which language will be used for reliability communications between the RC and its TOPs/BAs, and that determination has to be documented and available.
- Remember it's a functional-entity standard, not a single-person rule. COM-002-4 applies to Reliability Coordinators, Balancing Authorities, Transmission Operators, and Generator Operators as registered entities — the exam may frame a question around which entity had the compliance obligation, not just which individual operator was on the phone.
- Don't confuse three-part communication with the "most conservative action" concept. They show up in adjacent questions but they answer different problems — three-part communication is about confirming what was said; most conservative action (IRO-001/IRO-014 territory) is about what to do when there's ambiguity or disagreement. Keep them separate in your head.
5 Practice Questions
- Under COM-002-4, which of the following completes a compliant three-part communication for a Reliability Directive?
A. The issuer states the instruction and the receiver acknowledges with "copy."
B. The issuer states the instruction, the receiver repeats it back, and the issuer confirms the repeat-back is correct.
C. The receiver states the instruction back to the issuer before the issuer has spoken.
D. The issuer states the instruction and logs it; no verbal repeat-back is required if the instruction is later confirmed by email. - A Transmission Operator repeats back a Reliability Directive from the RC, but changes a breaker number in the repeat-back. What must the RC do next?
A. Accept the repeat-back since the intent was clear.
B. Correct the TOP and have them repeat the instruction back again until it is accurate.
C. Escalate immediately to the Regional Entity for a compliance violation.
D. Cancel the directive and issue a new one to a different operator. - Which NERC standard specifically addresses the language(s) to be used for reliability communications between an RC and its TOPs/BAs?
A. COM-002-4
B. COM-003-2
C. IRO-001-4
D. TOP-001-5 - Which of the following is an example of an Operating Instruction that would require three-part communication under COM-002-4?
A. A shift-change courtesy call confirming the operator on duty.
B. A weather update shared informally between control rooms.
C. An instruction to open a specific breaker to relieve a System Operating Limit exceedance.
D. A reminder about an upcoming scheduled maintenance outage next month. - An RC operator issues an instruction, and the receiving BA operator repeats it back correctly, but the RC operator says nothing further and moves on to another task. Has the three-part communication process been completed?
A. Yes — once the repeat-back is accurate, the process is complete regardless of confirmation.
B. No — the issuer must explicitly confirm the repeat-back was correct (or correct it) to complete the exchange.
C. Yes — silence from the issuer is treated as implicit confirmation under COM-002-4.
D. No — three-part communication requires a written log entry before it can be considered complete.
Answer Key & Explanations
- B. COM-002-4 requires three distinct steps: instruction issued, repeat-back given, and the issuer's confirmation of accuracy. A simple "copy" or an unconfirmed log entry does not meet the standard.
- B. When a repeat-back does not match the original instruction, the issuer must correct the receiver, who then repeats it back again — this loop continues until the repeat-back is accurate, per COM-002-4.
- B. COM-003-2 (Three-Part Communication) is the standard that requires entities to establish and document which language will be used for reliability communications between the RC and its TOPs/BAs.
- C. An instruction to open a breaker to relieve an SOL exceedance is a Reliability Directive / reliability-related Operating Instruction and requires the full three-part communication protocol. Routine or informal exchanges (A, B, D) don't carry that same compliance obligation.
- B. The process is not complete until the issuer confirms the repeat-back is correct. Silence or moving on without confirmation does not satisfy COM-002-4 — this is a common exam trap.
Three-part communication is one of those topics that's simple in concept but easy to get wrong on a scenario question when the details shift under you. If you want more RC-style practice questions built around real NERC standards, check out EPG Solutions' NERC RC exam prep resources.