How To Ground Electrical Enclosure: The Complete Guide

Proper electrical enclosure grounding is a vital facet for providing safety, performance and uptime.

However, it is always easy to overlook grounding aspects, or to fix them incorrectly.

Often, the 電気筐体 will perform as usual with incorrect grounding, though will result in a danger if a fault happens.

Control panels typically feature an input power feed having a grounding conductor that is ultimately bonded to the electrical enclosure.

This guide discusses some of the common practices on how to ground electrical enclosures:

Earth Grounding Of Electrical Enclosure

Earth grounding may not be an activity you will handle directly if designing electronics. However, it is still essential to understand the fundamentals of how to go about it.

This is due to the fact that it makes part of recognized best practices for designing safe electrical systems.

Specifically, you will be working your way about earth bonding systems to establish how a gadget associate with big power supplies.

Majority of commercial and residential power systems feature a grounding rod.

The earth grounding rod is an extremely conductive metal bar, which is sunk into concrete and gives a safety path for stray currents.

Grounded Electrical Enclosure

The electrical system components are linked to the earth ground by a grounding bar within the electrical enclosure.

In case an electrical fault happens, like ground fault or short circuit, the ground acts as safety feature guard against associated hazards.

Nonetheless, the purpose of earth grounding isn’t only to conduct the stray currents into the ground.

It is in effect to revert the power to its source, where the surge in current sets off overcurrent gadgets like circuit breakers.

These breakers then launch and stop the current flow.

Safety First

From a safety perspective, an electrical enclosure should be positively and correctly grounded so as to rid any electrical faults.

Resistance of the ground path from the electrical enclosure box back to source ground should be very low.

This ensures that when an energized conductor touches the 囲い, the consequential fault current gets low-impedance path to securely conduct to ground.

The enables the overcurrent parts to positively and speedily open and de-energize the circuitry to remove the power source.

Ungrounded or improperly grounded electrical enclosure will not get rid of a fault as speedily, in case it does.

Therefore, it can stay operating and energized, likely making the electrical enclosure to have a non-zero voltage.

People working around or within this enclosure box might get an electrical shock from the floating voltage.

Minimizing Noise

Good electrical enclosure grounding practices will assist in attenuating any electrical noise, like that produced by variable frequency drives (VFDs).

Low noise results in reduced likelihood of issues with sensitive equipment.

Grounding Hardware

You should list all the electrical connector hardware used in control panel enclosure grounding. Some of the usual termination ways for ground wires include:

• Grounding Lug: The fitting features a compression section that receives the incoming cable. There is a hole enabling you to bolt it to an appropriate backpanel or enclosure stud.
• Grounding Bar: This refers to a bar that can connect many ground conductors, and is typically attached to the backpanel.
• Grounding Terminal: A compression terminal block, commonly colored green/yellow or green, that grounds to DIN rail if installed or backpanel.

How To Ground Enclosure And Backpanel

Control panel enclosures are typically metal and feature an interior metal backpanel used for mounting components.

Even non-metallic electrical enclosures normally consist of a metal backpanel.

A UL-listed electrical enclosure will come accompanied with the relevant documents, which you must follow during installation.

Moreover, it will include the hardware that you will use for grounding all the metallic components of the enclosure cabinet.

The hardware may comprise of distinct ground sign sticker, which you need to place at every connection point.

Often, you land the incoming ground onto a backpanel-installed grounding terminal, bar, or lug.

This connector links the ground conductor to enclosure backpanel.

Backpanels are usually mounted using machine screws or nuts and star washers to make sure they are attached to the metal electrical enclosure.

Electrical Enclosure Grounding

Metal doors, regardless if removeable-hinge or continuous-hinge type, require independent bonding jumper from backpanel or enclosure to the door.

Typically, the doors feature studs for this role.

It is always advisable that electrical enclosure grounding connections done at painted exteriors have the paint scrapped to bare metal.

This is preferred even if you use star washers to ensure the best connection.

Furthermore, when you install DIN rail to the backpanel, you need to use tapped and drilled machine screws to create a bonded connection.

Grounding Conductors

You must size the grounding conductors according to the relevant industry standard, depending on size of overcurrent device that protects the circuitry.

The insulated ground conductors color is green or green having a yellow stripe, according to NFPA 79.

Nonetheless, there are instances where braided straps or bare conductors might be acceptable, like where flexibility is required. You can identify grounding spots with the term potential earth (PE) or a symbol.

Star Grounding

You should never perform electrical enclosure grounding connections in a “daisy-chaining” manner or successive jumpers.

This is due to the fact that any single failed interconnection would detach the ground coupling from all the subsequent devices.

Rather, you should use a “star” design where every ground features a home-run coupling to the primary grounding bar.

Grounding Power Supplies, VFDs, PLCs, And Other Devices

Common devices installed in electrical enclosures will normally have their specific grounding requirements.

Therefore, you must carefully follow the installation guidelines for power supplies, variable frequency drives, PLCs, among other devices.

This is because at times the grounding specifications are more restrictive, like needing oversized conductors compared to the ones would otherwise be required.

Chassis Ground And Isolated Ground

At times the terminology “chassis ground” is applied to define a grounded electrical enclosure. Manufacturers on occasions recommend “isolated ground.”

Nevertheless, majority of electrical enclosures need not to feature their entirely independent grounding system fixed.

A correctly fixed star grounding system offers a safe and dependable electrical control panel enclosure installation.

But, you may employ a chassis ground to ground electrical enclosure components. This technique entails designing one grounding location for the entire enclosure components.

For a number of reasons, it is beneficial having all your electrical current returns flowing across a single spot.

Among the most crucial reasons for using a chassis ground is the fact that it in fact acts as power distribution mechanism for your electrical enclosure.

Chassis Grounding of Electrical Enclosure

This type of ground can be easily observed in a truck or car. Vehicles utilize chassis ground as a means to circulate electrical current to all the parts that require it.

A vehicles starter, radio, air conditioning, among other components all have current flowing via the chassis ground.

The grounding mechanism is often on the framework or another metal part of the vehicle’s chassis.

Majority of chassis grounds are coupled at only one location to inhibit “ground loops” that may lead to interference.

This makes it critical to ensure your electrical device has a conductive chassis.

That is the reason why aluminum and steel enclosures are outstanding options for many kinds of electronic equipment.

They offer a simple and exceptionally conductive means of grounding and bonding electronics.

For any inquiries or questions about electrical enclosures, KDMSteel is here to help – contact us now.