Q: What are the types of faults detect in this system?
A: Three Line to Ground, three Line-to-Line and line to line are the types of faults detected in this system.
Q: What is three phase fault analysis?
A: The possible faults which occur in three phase are 3G, LL, 3L and analysis of these faults is called three phase fault analysis.
Q: How does the system protect from these faults?
A: It temporarily switches off the load when fault occurs for a very small time and goes to auto reset when fault is cleared or it permanently switches off the load when fault occurs for a longer duration of time.
Q: Why 6 lamps are used?
A: A series of two lamps are used to represent each phase. 2 lamps are connected in series to ensure safety.
Q: Can one replace the lamp by an induction motor?
A: Yes, the lamp can be replaced by an induction motor.
Q: What would be rating of the motor?
A: A 3 phase, ¼ HP motor should be used.
Q: What is the three phase induction motor rating to be used?
A: Three phase induction motor can be used, but limited up to 1 HP only as it uses a relay of 6A contact rating only. For higher HP just use a contactor of appropriate rating. The 230 AC coil of the contactor is powered in series from one of the contacts of the relay.
Q: Can we use this project in commercial purposes?
A: The features desired by real use can be done but cost would be high enough beyond the affordability of an average student expenditure point of view. Therefore the relay used in the project is totally different from the actual relay used in the control room.
Q: Can we test this project using single phase supply?
A: Yes. Connect primary of all the transformers of 1 to 6 to single phase supply.
Q: What to do when the lamp fails and what is the maximum lamp rating that can be used?
A: If the lamp fails one can use any lamp or bulb which is used in homes up to 100W. We suggest you to go for low watt bulbs.