19
18
power problemS
and their aSSociated caUSeS
All electrical and electronic equipment, connected to the mains supply is at risk of
being damaged from spikes, surges, lightning, brown-outs, power-cuts (blackouts),
power back surges, and over-voltage. The following is a summary of the main types of
power problems, causes and how these affect electrical and electronic equipment.
Spikes/Surge:
Very short, (one millisecond) event of very high surge in voltage to
thousands of volts and amps. Spikes are common in all parts of the world and repeated
exposure to spikes will damage electronic equipment and corrupt data.
what causes it?
Switching on/off of nearby equipment, lightning, motors starting etc.
rFi (radio Frequency interference)/noise:
high frequency disturbances that occur
within a short period of time (milliseconds). rFi & noise are very common in all parts of
the world and are the main cause of data corruption.
what causes it?
generated by high frequency noise from nearby equipment like
TV, radio equipment, transmitters, mobile phones, switching on/off of certain loads,
fluorescent lights, motor speed controls, light dimmers.
over-Voltage:
Long duration (milliseconds, seconds, minutes, hours or days) rise in
the voltage above acceptable limits. depending on the level of the over-voltage, the
damage can be instantaneous, severe and irreparable.
what causes it?
on return of mains supply after power cuts, under-sized utility
oscillating between periods of brown-outs and over-voltage or accidental (e.g.
accidental connection between two phases).
brown-out:
Long duration of low voltage (milliseconds to seconds, minutes, hours or
days). Very common in parts of the world especially where the power utilities are over-
stretched. Prolonged and frequent brownouts cause the equipment to malfunction
or not work at all. repeated episodes are certain to cause damage. motors and
compressors (and therefore fridges, freezers, coolers, air-conditioners and pumps) are
especially at risk. in time, damage is certain.
what causes it?
most commonly an over-stretched utility, especially in areas of poor
power distribution infra-structure and remote areas. common in dry seasons where
water is used for electricity generation.
basic lightning:
direct or nearby strikes can cause minor problems or severe
disturbances and damage. Lightning produces spikes/surges, over-voltage or power
cuts.
what causes it?
The surge is generated by either a direct hit, or indirectly striking
underground or overhead lines and transmitting high surges to connected equipment
in nearby buildings.
power-cuts:
common in many countries in the world, especially in areas of frequent
voltage problems. Sudden loss of power can cause damage ranging from corruption
of data to mechanical faults as equipment is stopped while in operation.
what causes it?
Power or sub station failure, breakdown in the distribution network,
or simply a plug being pulled out accidentally.
power-back Surges:
These typically occur when power returns after a power-cut
and connected equipment receives a surge of electricity at an over-voltage level,
which can be very damaging (see above).
what causes it?
Power back surges are created by the utility, when it restores
supply at an above normal voltage in order to compensate for the demand as
connected equipment re-starts simultaneously.
telecom surges, spikes and lightning:
Short term, high voltage and current
phenomena occurring on the telephone lines. can cause irreparable damage to any
piece of equipment connected to the incoming line. The telephone line itself may
even be damaged or destroyed in severe cases.
what causes it?
Telecom spikes are caused by lightning striking either the telephone
line directly or an object near it.
High Voltage
Power-Back
Surges
Advanced
Lightning
Low Voltage
Spikes/Surges
RFI / Noise
Power Cuts
Telecom Surges
Expert
Lightning
High Voltage
Power-Back
Surges
Advanced
Lightning
Low Voltage
Spikes/Surges
Basic
Lightning
RFI / Noise
Power Cuts
Telecom Surges
Expert
Lightning
Basic
Lightning
High Voltage
Power-Back
Surges
Advanced
Lightning
Low Voltage
Spikes/Surges
RFI / Noise
Power Cuts
Telecom Surges
Expert
Lightning
High Voltage
Power-Back
Surges
Advanced
Lightning
Low Voltage
Spikes/Surges
Basic
Lightning
RFI / Noise
Power Cuts
Telecom Surges
Expert
Lightning
Basic
Lightning
High Voltage
Power-Back
Surges
Advanced
Lightning
Low Voltage
Spikes/Surges
RFI / Noise
Power Cuts
Telecom Surges
Expert
Lightning
High Voltage
Power-Back
Surges
Advanced
Lightning
Low Voltage
Spikes/Surges
Basic
Lightning
RFI / Noise
Power Cuts
Telecom Surges
Expert
Lightning
Basic
Lightning
High Voltage
Power-Back
Surges
Advanced
Lightning
Low Voltage
Spikes/Surges
RFI / Noise
Power Cuts
Telecom Surges
Expert
Lightning
High Voltage
Power-Back
Surges
Advanced
Lightning
Low Voltage
Spikes/Surges
Basic
Lightning
RFI / Noise
Power Cuts
Telecom Surges
Expert
Lightning
Basic
Lightning
High Voltage
Power-Back
Surges
Advanced
Lightning
Low Voltage
Spikes/Surges
RFI / Noise
Power Cuts
Telecom Surges
Expert
Lightning
High Voltage
Power-Back
Surges
Advanced
Lightning
Low Voltage
Spikes/Surges
Basic
Lightning
RFI / Noise
Power Cuts
Telecom Surges
Expert
Lightning
Basic
Lightning
High Voltage
Power-Back
Surges
Advanced
Lightning
Low Voltage
Spikes/Surges
RFI / Noise
Power Cuts
Telecom Surges
Expert
Lightning
High Voltage
Power-Back
Surges
Advanced
Lightning
Low Voltage
Spikes/Surges
Basic
Lightning
RFI / Noise
Power Cuts
Telecom Surges
Expert
Lightning
Basic
Lightning
High Voltage
Power-Back
Surges
Advanced
Lightning
Low Voltage
Spikes/Surges
RFI / Noise
Power Cuts
Telecom Surges
Expert
Lightning
High Voltage
Power-Back
Surges
Advanced
Lightning
Low Voltage
Spikes/Surges
Basic
Lightning
RFI / Noise
Power Cuts
Telecom Surges
Expert
Lightning
Basic
Lightning
High Voltage
Power-Back
Surges
Advanced
Lightning
Low Voltage
Spikes/Surges
RFI / Noise
Power Cuts
Telecom Surges
Expert
Lightning
High Voltage
Power-Back
Surges
Advanced
Lightning
Low Voltage
Spikes/Surges
Basic
Lightning
RFI / Noise
Power Cuts
Telecom Surges
Expert
Lightning
Basic
Lightning