
2 Leg Burst Fire SCR Control Advantages
- 3 Phase, AC switch, Advanced Energy, AEG, Anodising Controller, Automation, Chlorinator, Controlled Bridge, Dimmer, Electric Furnace, Electrolysis, Electroplating Controller, Firing Card, Phase Angle Controller, Power, Power Controller, Power Regulator, Power Supply, Process Control, SCR, SCR Controller, Thyristor Controller, Thyro
- 27 Apr, 2020
Advantages of 2 Leg Control for 3 Wire, 3 Phase Systems using Burst Fire Control Method
Requirement for 2 Leg Control Method
- Burst Fire Control is Acceptable
- 3 Phase 3 Wire system
2 Leg Control Can Not be used in the following configurations
- 4 Wire System
- 3 Wire Inside Delta Wiring Arrangement
- Phase Angle Control
- Hybrid Phase/Burst Control
5 Main Advantages to 2 Leg Control
- High Efficiency/Economical – 33% less losses due to only switching two legs. The load current passes through 4 SCR’s instead of 6.
- Lower heat dissipation – Since we are only switching 2 legs, then the heat dissipation if 33% less than switching all three legs
- Safety – 3 Lage and 2 Leg Controllers have the same level of safety as both require a mechanical Contactor for safety disconnect. This is a clear requirement for the National Electricity Code since SCR’s are not considered a complete disconnect.
- Lower EMC and Harmonics due to having one phase connected at all times. This reduces potential clipping when one phase turns on while there is no return current path. 2 Leg Control generates less noise and harmonics than both 3 Phase Burst and Phase Angle Control
Conclusion
We Highly Recommend the use for 2 Leg Control for Open Delta, or 3 Wire Star applications using Burst Fire control, and in particular in EMC/Harmonics sensitive environments.
Reference of SCR Controller Wiring Topologies
Single Phase and 2 Leg
Three Phase Star
Three Phase Delta
Daniel Rehe
M.D. Fastron Electronics
Eng, Electronics RMIT
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