GFCI and AFCI Protection

Troubleshooting

Troubleshooting issues related to gfci and afci protection:

Overcrowded box

Box fill exceeds allowable volume per 314.16, common in renovation work

Backstab connections

Push-in connections on receptacles fail more often than screw terminals, poor practice though not a code violation

Double-tapped breaker

Two conductors on a single-pole breaker not rated for multiple conductors

Wrong breaker size

Using 20A breaker on 14AWG circuit (max 15A per 240.4(D))

Related Procedures

Ground-fault (5 mA trip) and arc-fault circuit interrupters for personnel and fire protection. GFCI/AFCI requirements and locations tested on JE and ME exams.

Relevant formula: Box fill is Sum of: conductors x volume + clamp allowance + device allowance + EGC allowance. Variables: Per Table 314.16(B): 14AWG=2.0 cu in, 12AWG=2.25 cu in, 10AWG=2.5 cu in.

Assessment Techniques

Ground-fault (5 mA trip) and arc-fault circuit interrupters for personnel and fire protection. GFCI/AFCI requirements and locations tested on JE and ME exams.

Relevant formula: Voltage drop is VD = (2 x K x I x D) / CM. Variables: K=12.9 (copper), I=amps, D=distance(ft), CM=circular mils.

Overview

Ground-fault (5 mA trip) and arc-fault circuit interrupters for personnel and fire protection. GFCI/AFCI requirements and locations tested on JE and ME exams.

Relevant formula: Box fill is Sum of: conductors x volume + clamp allowance + device allowance + EGC allowance. Variables: Per Table 314.16(B): 14AWG=2.0 cu in, 12AWG=2.25 cu in, 10AWG=2.5 cu in.