NEMA 280 : 1990
Withdrawn
A Withdrawn Standard is one, which is removed from sale, and its unique number can no longer be used. The Standard can be withdrawn and not replaced, or it can be withdrawn and replaced by a Standard with a different number.
APPLICATION GUIDE FOR GROUND FAULT CIRCUIT INTERRUPTERS
08-10-2000
01-12-2013
Foreword
Scope
1 Referenced standards and definitions
Referenced standards
Definitions
2 Characteristics of ground fault circuit interrupters
General
Principles of operation
Double grounded neutral protection
Test means
GFCI tripping characteristics
Types of GFCIs
Basic GFCI
Blank face type GFCI
Permanently mounted type
Circuit breaker type
Receptacle type
Portable type
Cord connected type
3 Ratings
Rating information
Class
Rated voltage
Rated frequency
Rated continuous current
Rated withstand current
Rated withstand current
Rated interrupting current
4 Markings
General
Types which are permanently connected into current
Class A devices
Class B devices
Portables and cord connected types
5 GFCI application considerations
GFCI application considerations
6 Installation guidelines for electrical systems with
GFCI
Location of GFCI on system
At load center or panelboard, or a permanently
mounted type after panelboard
At outlet box
Wiring considerations
At load
Portable units
Branch circuits
120V 2W - with equipment grounding conductor
120V 2W - older branch circuits without
grounding conductor
120/240V 3W - with equipment grounding
conductor
120/240V 3W - dedicated to an appliance
7 Field test devices
Integral test devices
Supplemental GFCI testers
Possible improper indications when using
supplemental test devices
Supplemental test device on circuits containing
leakage
Supplemental test device on circuit with open
grounding conductor
Supplemental test device on circuit with
reversed polarity
Supplemental test device on circuit with
grounded and equipment grounding and equipment
grounding conductors interchanged
Supplemental test device on circuit without
leakage
Supplemental test device on circuit with
reversal of line and load wires
Other test devices and test instruments
Periodic verification checks
8 Field troubleshooting
Line side of GFCI
At the GFCI
Load side of GFCI
Load side of neutral ground
Equipment ground and neutral connected together
on load side
Excessive leakage to ground
Multi-wired branch circuits (shared neutral)
High moisture conditions
Inability to reset tripped GFCI
Circuit breaker type
"Supplemental tester does not trip GFCI, but test
button does"
Appendix
A GFCI cross references to National Electrical Code -
1990 edition
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