Equipment Grounding Calculator
EGC Material = 1
OCPD Rating = 1
Grounding Conductor = 0
rating_material = [[1;2]; [2;3]; [3;4]; [4;5]; [5;6]; [6;8]; [7;9]; [8;10]; [9;11];[10;12]; [11;13]; [12;14]; [13;16]; [14;17]; [16;19]; [17;19]; [18;21];[20;23]; [22;23]]
Calculates the minimum size equipment grounding conductor based on the requirements of Table 250.122 of the 2014 National Electrical Code. NOTE: See additional commentary and clarification on equipment grounding below.
- EGC Material: Select either Copper or Aluminum equipment grounding conductors.
- OCPD Rating: Choose the appropriate rating of the overcurrent device protecting the circuit.
- Grounding Conductor: This is the minimum size grounding conductor needed for this installation.
NOTE: Equipment grounding conductors are the conductive path installed to connect the normally non-current-carrying metal parts of electrical equipment together and to the system grounded conductor and to the grounding electrode conductor, or both. Equipment grounding conductors can be approved metal raceways but are most commonly wire type conductors. Equipment grounding conductors are required for all feeders and branch circuits connected to electrical systems that are required to be grounded. To find the minimum size equipment grounding conductor for a circuit, choose the material of the grounding conductor to be used and select the rating of the overcurrent protective device protecting the circuit.
This calculator does not take into consideration the requirements found in section 250.122(B) of the 2014 National Electrical Code. When ungrounded phase conductors are increased in size, for any reason, the equipment grounding conductors must also be increased in size proportionately.
Section 250.122(A) of the 2014 National Electrical Code states that equipment grounding conductors are never required to be larger than the circuit conductors supplying the equipment.
Section 250.122(F) of the 2014 National Electrical Code requires that when conductors are run in parallel, a full size equipment grounding conductor must be run in parallel in each raceway or cable. This calculator does compensate for this requirement.
Calculate the minimum size copper equipment grounding conductor required for a 90 amp circuit.
- EGC Material: Copper
- OCPD Rating: 70 - 100 amps
The minimum size copper equipment grounding conductor for this installation is 8 AWG.