A momentary low voltage is a sag. A synonym would be a dip. Risks to electrical power supply: POWER FAILURE Blackout: complete loss of electrical power
Fault: momentary power outage POWER DEGRADATION Brownout: an intentional reduction of voltage by the power company.
Sag/dip: a short period of low voltage POWER EXCESS Surge: Prolonged rise in voltage
Spike: Momentary High Voltage In-rush current: the initial surge of current required by a load before it reaches normal operation.
– Transient: line noise or disturbance is superimposed on the supply circuit and can cause fluctuations in electrical power
Refence(s) used for this question:
Harris, Shon (2012-10-25). CISSP All-in-One Exam Guide, 6th Edition (p. 462). McGraw-Hill. Kindle Edition.