Because different entities have different power needs, emergency power services providers offer various types of power equipment, some for producing emergency power and some not. Below, we look at six types of power equipment commonly supplied by an emergency power service provider.
1. Uninterruptible Power Supply (UPS)
A UPS provides short-term emergency power when a regular input source fails. UPS units are different than standby generators in that they use batteries to provide instant power for low power use, and  flywheels to provide instant power for high power use. Some UPS devices can also correct utility power issues, such as: power failure, power surge, and frequency instability.
2. Standby Generators
Standby generators supply long-term emergency power when utility power is interrupted. Unlike UPS devices, they require no additional support in the case of high power supply. Usually running on diesel, liquid propane, or natural gas, standby generators are available in portable or stationary models, with the latter commonly found in buildings where emergency generators are required by law, such as hospitals and large commercial or residential or buildings.
3. Switchgear
Depending on its construction, switchgear is a system of electrical disconnects, circuit breakers, and/or fuses that control the power to electrical equipment, allowing it to be de-energized for maintenance purposes, and disengaged from abnormal flows of electricity. Different types of switchgear have different interrupting devices, such as: fuses, air blast circuit breakers, vacuum circuit breakers, and minimum oil circuit breakers.
4. Power Transfer Switches
A power transfer switch controls the crossover from utility power to generator power and vice versa. Most transfer switches are either open transition (brake before make) models, which connect a building to generator power after disconnecting it from utility power; or closed transition (make before brake) models, which do the opposite. Brake before make models are used in facilities that require constant power supply, such as: hospitals, data centers, and defense organizations.
5. Emergency Building Lighting
Emergency building lighting illuminates egress paths in the event of power outages. Some emergency lighting systems are battery powered, with each lighting unit containing its own battery, while others are connected to emergency back up generators. Emergency building lighting is traditionally required by law in large commercial and residential R1 buildings.
6. Power Distribution Units (PDU)
As their name suggests, power distribution units are used to supply power to various machines and apparatuses, which may connect to a PDU by direct plug in, or through a series of cables. Available as a portable unit or a stationary one, a PDU is purchased according to the level of power distribution required. Some common settings for power distribution units are: data centers, concert events, and laboratories with extensive computer equipment.
