The difference between two-stage and three-stage automatic transfer switches with dual power supply
1. There are only two switching states for the dual power two-stage system: S power supply - B power supply
There are three switching methods for the dual power supply three-stage mode: A power supply====completely in the middle position=====B power supply
2. Two stage dual power supply refers to a dual power supply with only two workstations, one for common power and one for backup power.
The dual power supply three stage type uses an intermediate position in addition to the two workstations for common and backup power.
3. Generally, the dual power supply two-stage type is only available in PC level, while CB level ones generally have three workstations.
Most manufacturers of PC grade high-capacity switches cannot achieve two-stage design! The middle position provides a buffer time for the impact generated during the switching process to facilitate arc extinguishing and ensure switching safety
CB level is generally a three stage dual power supply with protection function, that is, the switching switch of high load or short circuit circuit circuit switches to the middle position, and both power sources are powered off at the same time, which violates its inherent function. Ensure the continuous and reliable operation of electrical equipment! Another possibility is that the CB level three section dual power switch has two circuit breakers or contactors with mechanical interlocking, electric devices As is well known, CB level dual power supply has a protection function. When a short circuit circuit occurs, the dual power supply protection acts to trip, because one circuit trips and the other is closed simultaneously by mechanical interlocking. If the short circuit circuit is not eliminated, it will cause repeated damage to electrical equipment, and such switching is meaningless!
