Industrial Electrical Services

Switchgear

SME Inc. of Seattle has 40 years of experience in the industrial installation and maintenance of low voltage (LV) and high voltage (HV) switchgears. We design, install, repair and perform maintenance on LV & HV switchgears.

High Voltage (HV) Switchgear

The function of HV switchgears is to protect segments of the electrical grid from interruption due to overload and/or short circuits, while preserving the flow of electricity to other areas of the system. Through a series of circuit breakers, fuses and electrical disconnects, a switchgear isolates electrical equipment to allow for service, maintenance or to clear faults further down the system. High voltage switchgears interrupt 35,000 volts AC or more.

Circuit breakers in HV switchgears are the dominant components in stopping arcing and require accurate design. At SME Inc of Seattle, we have the experience, knowledge and dedicated designers to accurately and safely design the necessary components for any type of HV switchgear for any facility. Common Types of internal HV Switchgear circuit breakers are:

• Air
• Gas
• Oil
• Vacuum

Low Voltage (LV) Switchgear

SME Inc. of Seattle brings their decades of experience and professional electricians, designers and staff to every LV switchgear project and our safety record is unmatched. Low voltage switchgears interrupt voltages less than 1000 volts AC. LV switchgear offers electrical protection, isolation and switchgear control.

Protection:

• Of people in case of an insulation failure – circuit breakers, fuses, residual devices, and/or permanent monitoring
• Of motors, appliances from overheating – Thermal relays designed to match needs of motor use
• Of circuit elements from overload and short circuit currents – circuit breaker, fuses

Isolation separates the circuit from the energized system allowing employees to work on the isolated area in safety, while allowing the rest of the systems to continue to operate normally.

Isolation:

• Clearance between distance of creepage, contacts, etc. must comply with international and/or national standard
• A key locked system in an open position must be provided to thwart re–closure by accident or unauthorized action
• Circuit poles, including neutral must open – unless a PEN conductor is neutral
• Visual or mechanical verification that the contacts are open for an isolating device

Control of switchgear functions will provide personnel the ability to modify a loaded system within system requirements, at any time. Control will cut the energy of a live circuit that may cause an electrical fire or shock or completely stop a dangerous movement.

Control:

• Emergency stop or switching - to terminate flow or de-energize a live circuit
• Functional control – in normal service, control of part of the system or an individual piece of equipment, etc
• Maintenance control – machine stoppage without possibility of inadvertent re–starting

Switchgears are installed to protect people, machinery and the electrical system as a whole. At SME Inc. of Seattle safety is our top priority throughout the design phases as well as any time we are on the job. We have a dedicated safety director and our employees are continuously trained on our safety policy. Call SME Inc. of Seattle when you need LV or HV switchgear repair, maintenance or installation.