In many low voltage projects, a choice of switchgear vs. switchboard will often come up, and project owners have to decide which equipment fits their situation. Because while both switchgear and switchboard may serve a similar purpose, there are key differences that make them suit specified applications. In this post, we compare the two.
Switchgear and Switchboard Apparatus
Switchgear and switchboard refers to the type of equipment used to manage and distribute power while also protecting electrical circuits and equipment. They consist of electrical disconnect switches, fuses or circuit breakers, and other devices that ensure power system safety and reliability.
As you can see, both switchgear assemblies and switchboard are electricity distribution apparatus. However, many features make them different. In order to explain these variations, we’ll start by looking at the definition of each before delving into the features that distinguish each from the other.
Switchgear is an assembly or combination of electrical devices used to isolate or protect electrical circuits. Switchgear uses include automatically breaking and switching on power in an electrical system, allowing electricians de-energize circuits for service, and monitoring power systems.
Switchgear may be open air devices used to protect an overhead power line, or it may come in the form of enclosed assemblies mounted with switchgear components. These include switches, fuses, and busbars for controlling, protecting, and isolating sections of electrical systems in buildings and other facilities.
Definition of Switchboard
A switchboard is an electrical control assembly that houses switches, circuit breakers, and fuses used to distribute electrical power in a building or other facility. The switchboard components may also include meters, relays, and other electrical control and protection gadgets.
A switchboard may be as simple assembly of switches and safety devices enclosed in a metal structure and mounted on a wall, or it may be an elaborate free standing structure used to control the distribution of power in a large industrial facility.
Switchgear vs. Switchboard
We have already looked at the definitions, but what is the difference between switchboard and switchgear? Variations range from design and application to the components included. They also include voltage ratings, installation locations, and even cost. Let’s take a closer look at every difference.
Switchgear vs. Switchboard: Design
A major difference between switchgear and switchboard lies in the design of parts. Switchgear components include serviceable, draw out (fully or partially) breakers that employ solid insulation to shield them from other sections.
In contrast, switchboard breakers are usually bolted in place to the bus and only use air as the barrier between the them and other parts. This design makes switchboards smaller, but it also means the breakers are not serviceable and can only be replaced.
It’s also worth noting that switchgear typically uses a rear compartment for cable terminations. A switchboard features front terminations, which makes it wall-mountable and less bulky when compared to a switchgear unit.
Switchgear vs. Switchboard: Voltage
Another main difference between switchgear and switchboard is the voltage rating. Switchgear voltage rating is wider, ranging from a few to thousands of volts. For example, low voltage switchgear has a voltage range of up to 1kv, while medium and high voltage switchgear has a voltage range of up to 366kv and higher.
On the other hand, electrical switchboards are designed for use with lower voltages, typically below 600 V. For instance, a typical residential switchboard has a voltage rating of 120/240 V. Commercial and industrial facilities, on the other hand, may have switchboards with ratings of up to 600 V.
Switchgear vs. Switchboard: Arc Safety
Switchgear is designed to contain an electrical arc and comes with more elaborate insulation methods such as air, gas, oil, solid dielectric, and even vacuum. In switchboards, some of these arc flash quenching techniques may not be present as they’re not a requirement by industry standards.
But although switchboards are not required to contain an electrical arc, they may include features that mitigate the effects of an arc flash, such as Arc-Resistant Switchboards.
Switchgear vs. Switchboard: Cost
Switchgear assemblies are elaborate and robust structures that cost more than switchboards. As an example, switchgear uses draw out breakers compared to the fixed low voltage MCCBs used in switchboards. These will generally cost more.
Switchgear breakers are also designed with higher 30 cycle withstand-current compared to only 3 cycles of switchboard breakers. The current withstand level refers to the highest momentary (0.5 seconds) fault current that a breaker can tolerate without damage.
Switchgear vs. Switchboard: Application
LV or low voltage switchgear is typically used to control, protect, and isolate electrical equipment or circuits in residential and industrial settings such as factories, power plants, and mines. As such, it’s often installed on the secondary side of the power entry transformer where it supplies switchboards and other equipment.
A switchboards assembly is normally used to distribute electrical power in a building or structure. So you will commonly find them in residential and commercial settings, such as homes, offices, and stores. Some may even receive power from switchgear installation before feeding it to loads within a facility.
Switchgear or Switchboard?
Construction managers and engineers often face the choice between switchgear and switchboard when selecting power distribution equipment. If you’re a facility owner, you might also be interested in knowing what equipment is suitable for your investment.
Generally, electrical switchgear offers higher levels of system reliability than switchboards. It’s also more serviceable, seeing that it comes with draw-out breakers that can be removed without having to de-energize the structure. Other benefits include remote monitoring and operation, which means increased reliability.
Overall, switchgear best suits situations where system integrity is paramount, such as data centers, airports, and medical facilities. Switchboard is best utilized in lower level systems, and where outages are not a main concern. Being smaller and less costly, it’s often an option when space and budget are a project’s major constraints.
Switchgear and switchboard present distinct variation in many aspects, from voltage levels and design to application and cost. We hope this electrical vs. switchboard article has provided you with a clearer insight into the differences that exist in the two apparatus. Most importantly, you now understand situations that call for switchgear and those that suit a switchboard.