Branch Circuits

Key Values & Ranges

Key values for branch circuits:

• Ohms law: E = I x R Example: 120V circuit with 10 ohm load: I = 120/10 = 12A
• Voltage drop: VD = (2 x K x I x D) / CM Example: 20A, 150ft, 12AWG (6530CM): VD = (2 x 12.9 x 20 x 150)/6530 = 11.87V (9.9%)
• Power (3-phase): P = 1.732 x E x I x PF Example: 480V x 20A x 0.85 x 1.732 = 14,117W

Patient Communication

Clear communication about branch circuits with patients, families, and the healthcare team is essential. Use standardized handoff tools (SBAR) for shift changes and transfers. Verify understanding by asking the patient to repeat key information back to you.

Documentation

Proper documentation of branch circuits follows facility policies and regulatory requirements. All entries must be dated, timed, and signed. Errors are corrected with a single line through the incorrect entry, initialed and dated. Never erase or cover with correction fluid.

Overview

Circuit conductors between the final overcurrent device and outlet(s), classified by OCPD rating: 15A, 20A, 30A, 40A, 50A. Core JE exam topic under NEC Article 210.

Relevant formula: Power (3-phase) is P = 1.732 x E x I x PF. Variables: P (watts), E (line voltage), I (line current), PF (power factor).

Step-by-Step Procedure

Circuit conductors between the final overcurrent device and outlet(s), classified by OCPD rating: 15A, 20A, 30A, 40A, 50A. Core JE exam topic under NEC Article 210.

Relevant formula: Conduit fill is 1 wire=53%, 2 wires=31%, 3+ wires=40% of conduit area. Variables: Wire area from Chapter 9 Table 5, conduit area from Table 4.