Switchgear is essentially a key component of electric utility transmission and distribution systems. This device consists of switches, fuses, circuit breakers, and other parts that protect, separate, and control electrical equipment. Switchgear acts as a collective centralized piece of equipment in extensive industrial and commercial facilities. Switchgear plays a significant role in protecting electrical equipment and averting hazards. It is not unusual to find medium voltage switchgear in major industrial setups.
What exactly does switchgear do?
The very purpose of switchgear is to switch, protect and control the circuits. Switchgear units are automated protective devices that can quickly close the trip circuit in case of a fault. Without switchgear, excessively heavy loads of electricity can pass through the circuit and cause damages. Switchgear can selectively shut off the faulty section of the circuit and allow power to keep flowing to the healthy sections. In turn, this also keeps the connected devices safe in case of electrical faults. Based on the requirements, the industry can use a highly secure unit such as an arc flash switchgear or one with regular safety features that are effective too.
What are the types of medium voltage switchgear?
Different applications require different technologies and protective measures. This calls for various types of switchgear units. Some of the key types of medium voltage switchgear are:
1. Arc Resistant Switchgear
Arc flashes from major electric faults result in a tremendous surge of power thatregular switchgearmay not be able to contain. An arc flash switchgear has the ark flash energy and diverts it away from the operator through a plenum. Ultimately, it releases the energy in an open area such that the energy would not cause any harm.
2. Vault or Subsurface Switchgear
This type of switchgear lies under the surface but allows the users to operate from above ground. The locations where this type of switchgear is applicable can either be dry or subject to water ingress. Vault switchgear uses SF-6 gas, solid materials, and solid-dielectric-in-air technology for insulation. Vacuum interrupters help to separate faults and protect the loads.
3. Metal-clad Switchgear
Metal-clad switchgear refers to a type of switchgear unit where separate metal compartments enclose components such as the main switch or circuit breaker, instrumentation, incoming bus, outgoing bus, etc. This type of switchgear is relatively popular due to the safety features and the ease of maintenance it comes with.
4. Metal-enclosed Switchgear
This switchgear comes with various safety features, such as circuit breakers, fusible switches, and power fuses. These devices usually stay in common compartments, together with the metering and control equipment. Metal-enclosed switchgear finds application in commercial as well as industrial setups.
5. Pad-mounted Switchgear
Pad-mounted switchgear is helpful in the case of systems that lie underground. This outdoor-rated and tamper-resistant switchgear uses vacuum interrupters, fuses, and switches to reduce the chances of outages, separate faults, and protect loads. This type of switchgear finds application in feeder sectionalizing, utility distribution, and circuit protection.
Essentially, different types of medium voltage switchgear offer varying levels of protection and come with their unique features. Leading brands like Solution Controls manufacture various models of switchgear, including arc flash switchgear for applications that require high levels of protection from arc flashes.