If you have a generator as a backup in the case of the local electricity mains failing, it is a legal requirement to have a transfer, or changeover, switch. This is for two reasons.
First there is the danger to electricity workers. If the generator has been powered up and the mains reconnects, it could back feed electricity into the mains. There is also a danger to the generator because if the mains powers up again while it is running it could burn out your generator. So, the system is designed so that the generator and the mains can never be in contact with one another.
Now your transfer switch can either be manually operated or it can be automatic. A manual changeover switch requires somebody to be on the premises when the mains power goes down whereas an automatic transfer switch does not. Both perform the same function, but the automatic transfer switch does it automatically which saves time and reduces the power outage length.
If the power goes down and you have a manual changeover switch, it means that you have to go to wherever the generator is situated and start it up. Once it is up and running, you can then manually switch to the generator. Of course, when the mains power comes back on you have to reverse the procedure by switching off the generator and only then can you switch back to the mains.
The Automatic Switch Does It For you
An automatic changeover switch does all this for you. It monitors the mains power and when it goes down it sends a signal to the generator to start. When the generator is running at full speed it sends a signal back to the transfer switch telling it to disconnect from the mains and connect to the generator.
Some automatic transfer switches do not have mains detection built in. In this instance, the mains detection would have to be in the generator or elsewhere. If the generator detects a mains power outage, it sends a signal to the automatic transfer switch to disconnect from the mains and then starts up. Once it is running it sends a signal to the changeover switch to now connect to the generator.
At Blades Power Generation we have a complete range of both manual and automatic changeover switches. Manual transfer switches are less expensive, but for the sake of convenience, an automatic transfer switch is the preference of most people.
