Load Calculations

Patient Communication

Clear communication about load calculations 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 load calculations 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

Determining total electrical demand using NEC Article 220 standard and optional methods to size service and feeders. Among the most complex and heavily weighted JE and ME exam topics.

Relevant formula: Transformer sizing is kVA = (V x I) / 1000 (single-phase), kVA = (V x I x 1.732) / 1000 (3-phase). Variables: V=voltage, I=current, kVA=kilovolt-amperes.

Practical Example

Safety Considerations

Safety requirements relevant to load calculations in electrical work:

1. Ground fault protection of equipment required on 480Y/277V services over 1000A per 230.95
2. NFPA 70E arc flash boundaries: limited approach, restricted approach, prohibited approach based on voltage and available fault current
3. Working space clearances per 110.26: minimum 3ft depth, 30 inch width, 6.5ft headroom for under 600V equipment
4. Lockout/tagout (LOTO): de-energize, lock, tag, try, verify zero energy before working on equipment

Differential Diagnosis

When studying load calculations, carefully distinguish it from related but distinct concepts: branch circuits, nec code, ohms law. Exam questions often test your ability to select the most specific and appropriate answer when multiple options seem partially correct. Look for the option that most completely addresses the scenario presented.