Home >  Q&A
UPS Bypass Mode and Bypass Switch Guide
2020-12-14

What is Bypass Mode in UPS?
In normal mode, the load is provided with voltage-stabilized and frequency- stabilized power by the inverter, and meanwhile, the battery is charged. But UPS Bypass mode is when you switch the circuit from going through the UPS to going around or bypassing it. In this mode, the load is directly supplied by the mains without the protection of the UPS.

All industrial on-line uninterruptible power supplies contain static and manual (service) bypass and there are two main types of bypass switch that serve similar but distinct functions:internal bypass switch(static bypass switch)and external maintenance bypass switch.

What is a static bypass switch?
When the UPS system has an internal failure, failure, or overload, the static bypass switch will automatically convert the load to utility power immediately. It’s a built-in internal bypass and permits a transfer in less than four milliseconds(1/4 of an electrical cycle. It can also be switched manually if needed.

static bypass switch wiring diagram

What is a maintenance bypass switch?
While a Maintenance Bypass Switch is a manual bypass switch used to remove the UPS system from the circuit for servicing or maintenance. It is usually a wrap-around switch either of rotary or MCB design which allows the UPS to be powered down with the load powered directly from the mains whist maintenance is carried out on the UPS.

maintenance bypass switch wiring diagram

What's the function of a maintenance bypass switch
The maintenance bypass switch allows engineers to isolate the power to completely bypass the UPS without causing load interruption. In addition, it allows the engineer to remove power from the system for servicing or removal, without power interruption for load.

If you have any other questions about bypass mode, normal mode or bypass switch, feel free to contact us for help. sales@kstar.com.


Cookie Policy

By continuing to use this website, you agree to our use of cookies.Read our privacy policy>