Pressfit’s SFT1 MCB Changeover Switch (COS) enables us to switch the load between two power supplies. In most cases, the COS is used to switch to a backup line when the main line needs to be taken offline for repair and maintenance. It is widely used in industries and in domestic locations where continuity of supply is necessary. It finds a lot of use in individual bungalows due to the same reason.
Changeover switches, in principle, disconnect switches independently based on manual operation, and can make, carrying, and breaking currents under normal circuit conditions. The COS has 3 positions – I-O-II with the center line being the off. The SFT1 COS comes in 2 types – DP and FP – for single and three phase applications, just like other circuit breakers.
1. Switch off MCB and disconnect the power supply.
2. Mount COS over DIN rail with snap at bottom.
3. Check operation of knob position before connecting cables
4. When Knob position is I
a. Top indicator is RED, Bottom indicator is GREEN
b. Load is connected through power supply I
5. When Knob position is II
a. Top indicator is GREEN, Bottom indicator is RED
b. Load is connected through power supply II
6. When Knob is at MID position
a. Both indicators show GREEN & it is a No Load / Off position
7. Connect cables at incoming & outgoing terminals.
8. Select power supply (I or II) for Load.
9. Switch the MCB on.
Current Rating (In)
25A, 40A, 63A
Rated Voltage (Ue)
Rated Frequency (f)
Rated Insulation Voltage (Ui)
Rated Impulse Voltage (Uimp)
2500V for 1 minute
-5° to 50° C
Clip on DIN Rail (35mm x 7.5mm)