Emergency Power Switch Gear Controls: How Do They Work?

Switch gear controls-also referred to as switchgear-are a combination of fuses, circuit breakers, and/or electrical disconnects that isolate electrical equipment within a power system. Concerning emergency back up generators, discussion of switchgear centers mainly on electrical disconnects and circuit breakers, as they allow buildings to switch from commercial power to generator power when an onsite computer detects signs of an impending power outage in the commercial power supply. When a problem is perceived, switchgear usually switches a building’s power supply to generator power under one of two scenarios: break before make, or make before break.

Switch Gear Controls: Break Before Make Vs. Make Before Break

Whether a back up generator’s transfer switch operates in a break before make or a make before break scenario depends mainly on a building’s power needs, although both types of switches usually operate automatically when an entity doesn’t employ maintenance staff familiar with generators. Below, we examine the differences between break before make and break before make switches.

Break Before Make Switches

This type of switchgear is most common in residential generators and generators at businesses and organizations that don’t require uninterrupted power supply to preserve critical functions. In a break before make scenario, a generator disengages from commercial power before switching to generator power. When break before make switches are manual instead of automatic, it brings the advantage of generator fuel not being wasted due to false detections of commercial power supply problems, which sometimes occurs with automatic switches.

Make Before Break Switches

This type of switchgear is most common in entities that require uninterrupted power supply to preserve critical functions. In a make before break scenario, a building switches to generator power when an onsite computer detects signs of an impending power outage in the commercial power supply, thus avoiding a power outage. Some common types of businesses and organizations that require make before break switches on their back up generators are hospitals, data centers, laboratories, and defense organizations.

The Importance of Transfer Switch Maintenance

Because backup generators are seldom used, the tendency to view their maintenance as dispensable is more common than with other machines, especially due to the misconception that, because the generators are seldom used, they therefore require less maintenance. The upkeep of emergency generators requires a regular maintenance schedule the same as other machinery, with a primary maintenance concern being transfer switch servicing. Over time, transfer switches can fall prey to inner oxidization, wear due to testing, and accretions of dirt and grime that could penetrate sensitive parts, potentially causing them to malfunction during a real world switchover. For companies and organizations that don’t employ maintenance staff familiar with generator operation, contracting with a supplier of emergency power solutions to perform regular transfer switch maintenance is the best idea.