Use the cabinet's intended conductor entry, or choose a connector identified for the actual grounding conductor and installation. A cable connector that grips the conductor is not automatically suitable for that use. Mechanical support, enclosure sealing, electrical bonding, and conductor termination are separate requirements. Establish whether the conductor is a grounding electrode conductor before selecting hardware. Then match the entry and termination to the equipment instructions, applicable code, and authority having jurisdiction.
Identify the conductor before choosing hardware
A grounding electrode conductor, or GEC, connects the system's grounding arrangement to the grounding electrode system. An equipment grounding conductor provides the equipment fault-current path. A bonding jumper connects conductive parts together. These functions can require different connection points and installation details.
Do not choose an entry fitting from wire color or diameter alone. Establish the conductor's function from the electrical drawing and equipment instructions.
Record these details before selecting an entry:
- Conductor function and intended termination point.
- Copper or aluminum, conductor size, and solid or stranded construction.
- Bare, covered, or insulated construction, including actual outside diameter.
- Cabinet function, such as service equipment or downstream distribution equipment.
- Any protective raceway between the cabinet and grounding electrode.
- Exposure to water, chemicals, vibration, or physical damage.
The grounding and bonding guide covers the broader fault-current path and cabinet bonding requirements. This entry decision starts after you identify those functions.
What a connector listing establishes
A connector's listing applies to its identified uses and installation conditions. Its appearance, trade size, or ability to tighten around a conductor does not establish suitability.
A connector identified only for nonmetallic-sheathed cable is not automatically suitable for an individual bare GEC. Conversely, do not reject every plastic or two-screw connector by appearance alone. Check the exact product documentation for the intended conductor and application.
Verify the following separately:
| Documentation item | What you need to establish |
|---|---|
| Intended use | The fitting permits the actual individual conductor or cable construction |
| Conductor range | The specified size, material, and construction are covered where applicable |
| Entry dimensions | The hole, thread, and cabinet wall thickness match the fitting instructions |
| Mechanical function | The fitting provides the required retention or edge protection |
| Bonding function | Any claimed electrical bond is documented for that use |
| Environmental protection | The installed fitting and seals suit the required enclosure exposure |
| Installation method | Required hardware, orientation, and tightening instructions can be followed |
A size marking alone does not answer every question in this table. Read the instructions associated with the exact fitting, not a similar-looking component.
The distinction between retention and other fitting functions also appears in cable gland versus cord grip terminology. Neither name alone establishes suitability for a GEC.
When an intended entry needs no separate connector
Some equipment provides a dedicated conductor opening with an installation method described by the manufacturer. A separate connector is not a universal requirement for every grounding conductor entry.
Use that opening only for the conductor and arrangement the equipment instructions permit. Check edge protection, conductor support, physical protection, and environmental limitations. A small factory opening does not establish that any conductor may pass through it under any conditions.
A field-drilled hole requires a separate review. Confirm that the equipment permits the modification and that the location avoids internal parts, mounting features, and sealing surfaces. Specify an accepted entry arrangement rather than assuming a deburred hole is sufficient.
Likewise, drilling does not automatically invalidate every equipment approval. Its acceptability depends on the equipment, permitted modifications, installation conditions, and required evaluation. Resolve uncertainty before cutting, particularly for service equipment or equipment subject to utility requirements.
Keep support, bonding, and termination separate
Mechanical retention prevents unwanted conductor movement. Edge protection prevents abrasion. Bonding provides electrical continuity. Termination connects the conductor to an identified electrical connection point.
One fitting may perform several functions, but only when its documentation establishes those functions. A plastic fitting does not provide an electrical bond through its body. A metal fitting does not prove a suitable bond merely because it touches the cabinet.
For a GEC routed through ferrous protective raceways or enclosures, evaluate the applicable NEC continuity and bonding requirements. These can require bonding the protective metal path to the GEC at both ends. Do not transfer that rule into a blanket statement that every cabinet entry requires the same bonding fitting.
Review the complete route, including sleeves, raceways, intervening enclosures, and the electrode connection. A correctly installed entry fitting cannot compensate for an incomplete bonding arrangement elsewhere.
The cable gland bonding requirements article explains why a metal entry fitting and a verified electrical bond are different things. GEC installations also need their own route-specific review.
The internal termination requires equal attention. At service equipment, use a permitted GEC connection consistent with the equipment's identified terminals and main bonding arrangement. Do not assume an arbitrary cabinet-mounted lug is an acceptable substitute.
At downstream equipment, do not add a neutral-to-cabinet connection merely because a grounding conductor enters there. Follow the equipment function and approved grounding design. Confirm terminal conductor range, material compatibility, permitted conductor count, and tightening torque.
What enclosure ratings do not establish
Environmental ratings address specified exposure conditions. They do not establish that a connector accepts a bare conductor or provides an approved GEC termination.
Our stainless enclosures are rated NEMA 4X / IP66 by the manufacturer; not UL listed. Those ratings do not make every field-installed fitting suitable, nor do they establish approval of a completed service or control assembly.
An entry assembly must meet both the electrical installation requirements and the environmental requirements. A fitting may be suitable for the conductor but unsuitable for hose exposure. Another may seal a jacketed cable correctly without being identified for a bare conductor.
Bare stranded conductors need particular attention because water can travel through spaces between strands. A seal against the conductor's outside surface does not necessarily stop that path. Require documentation covering the actual conductor construction and exposure.
Review the complete assembly under the applicable requirements of NEMA 250, UL 50E, or IEC 60529 as appropriate. For installation details, use the article on installing a cable gland without losing the rating, while separately verifying suitability for this conductor.
Make the entry decision before fabrication
Resolve the electrical arrangement before choosing the hole diameter. Start with the intended termination and conductor route, then select the entry hardware.
For an existing cabinet, first inspect its documentation for a dedicated entry and permitted field modifications. If neither clearly covers the proposed arrangement, obtain clarification from the equipment manufacturer and authority having jurisdiction.
For a new cabinet, place the entry where the conductor can reach its terminal without excessive bending or interference. Allow room for locknuts, sealing washers, bonding hardware, tools, and terminal access. Check both sides of the wall, not just the visible opening.
Do not enlarge a hole until the fitting's required opening and wall-thickness limits are confirmed. A nominal thread designation is not necessarily the required clearance-hole diameter.
For custom stainless enclosures and factory cutouts, identify the conductor entry as an electrical interface on the approval drawing. A factory-cut opening provides geometry; it does not, by itself, establish the finished entry's bonding or environmental performance.
What to specify on the approval drawing
Specify the entry as an assembly rather than a hole with an approximate location. Include the following information:
| Drawing field | Information to provide |
|---|---|
| Conductor identification | GEC, equipment grounding conductor, or bonding jumper |
| Conductor construction | Material, size, stranding, insulation status, and outside diameter |
| Entry hardware | Exact fitting identification and applicable installation documentation |
| Opening | Diameter or thread, tolerance, face, and location from fixed datums |
| Cabinet interface | Material, wall thickness, sealing surface, and access clearances |
| Bonding arrangement | Required connection points, hardware, and protective-raceway treatment |
| Internal termination | Identified terminal, conductor range, and installation instructions |
| Environmental requirement | Exposure conditions and required finished-assembly protection |
| Acceptance requirements | Equipment, project, utility, and authority requirements as applicable |
Use the cutout designer to communicate opening locations and spacing. Send the fitting documentation with the layout so the opening can be checked against the actual hardware.
Keep the approved drawing and installation instructions with the panel documentation. Before energizing, verify mechanical security, the required bonding continuity, correct termination, and the installed seals. A continuity reading alone does not establish a compliant conductor entry.
Enclosures for this job
Catalog sizes that suit the job this article answers, picked from its subject; open one for its full specifications.
| Enclosure | Material | Outside H x W x D / display | Rating |
|---|---|---|---|
| 60 × 36 × 16 in | 304 stainless | 60 x 36 x 16 in | Rated NEMA 4X / IP66 by the manufacturer; not UL listed |
| 48 × 36 × 16 in | 304 stainless | 48 x 36 x 16 in | Rated NEMA 4X / IP66 by the manufacturer; not UL listed |
| 60 × 36 × 12 in | 304 stainless | 60 x 36 x 12 in | Rated NEMA 4X / IP66 by the manufacturer; not UL listed |
Questions
Can a nonmetallic-sheathed cable connector hold a bare grounding electrode conductor?
Not automatically. A connector identified only for nonmetallic-sheathed cable does not establish suitability for an individual bare conductor. Check the exact fitting's listed uses, conductor range, installation instructions, and environmental limitations. Choose hardware documented for the actual application rather than relying on physical fit.
Does every grounding conductor entry require a separate connector?
Not in every installation. Equipment may provide a dedicated opening and instructions that permit a particular conductor entry without a separate connector. Verify those instructions, conductor protection, support, and environmental conditions. Do not assume an undocumented field-drilled hole is equivalent to an intended factory entry.
Does a metal entry fitting automatically bond the grounding electrode conductor?
No. Contact with metal does not establish a suitable electrical bond. The fitting, mating surfaces, installation method, and any bonding hardware must provide the required connection. A grounding electrode conductor routed through a ferrous protective path also requires review of the applicable continuity and bonding requirements.
Where should the grounding electrode conductor terminate inside the cabinet?
Use a connection permitted for the equipment's function and identified grounding arrangement. Service equipment requires attention to the grounding electrode connection and main bonding arrangement. An arbitrary cabinet lug is not automatically acceptable, and downstream equipment must not receive an unintended neutral-to-cabinet connection.
