It is a known fact that Lightning surges are more destructive than switching surges but data shows that
malfunctions & premature failures of sensitive electronic and electrical equipment occur much more as
a result of switching surges than lightning surges due to the fact that there are many sources of
It is to be noted that the incidence of lightning and lightning induced surges is lesser in western parts of India
as compared to eastern parts of the country. Also, in spite of installation of various types of protective devices,
failure of such devices happens very frequently.
Proper selection and installation technique of SPDs is the only solution to protect your equipment
against these switching surges.
There are many sources of switching surges. Most common ones are listed below,
1. High voltage switching from Utility side (Electricity Boards)
2. Capacitor bank switching
4.Transfer from EB to DG & vice versa. (there is no BUMPLESS transfer, practically)
5. Transmission line switching
6. CCVT- Coupling Capacitor Voltage Transformer
9. Ground voltage differences
11. Electro-mechanical equipment
13. Digital logic circuits (SMPS, Printers, unshielded cables viz flat ribbon cables)
14. DC control circuits
15. Mechanical vibration
16. Chemical contamination
17. ESD via human touch
18. Cable resonance
19. Reflections & travelling waves
20. Power circuit in-rush currents
21.Other Incidental sources such as on load tap chargers, corona discharge from HV transmission lines
(which travel several kilo-meters from the point of generation by propagating along the line) etc.
Contact us for expert solution to protect your sensitive electronic equipment close to their MTBF levels against
the disturbances caused by any one or combination of the above-mentioned sources.
As this is a very specialized and sensitive subject, proper Selection and Installation of SPDs are very important
to ensure trouble free operation for many years.