in the land of smiles...

A transfer switch allows safe switching between your mains supply (primary source) and your standby generator supply (secondary source) whilst ensuring both sources cannot be connected simultaneously. I'm sure you've figured out by now, that an automatic transfer switch carries out this operation automatically...

It does so by continually monitoring the incoming mains supply. If the voltage of the mains supply fails, is significantly reduced to create a brownout condition or surges outside of pre-determined parameters, it will immediately disconnect the mains supply and command the generator to start. Once the generator is producing a stable supply it will transfer the load to the generator. When a stable mains supply is restored it will carry out the reverse process, transferring the load back to the mains and shutting down the generator.

For many years automatic transfer switch panels relied on a circuit of obtrusive phase failure relays, voltage balance relays and timers to achieve this process, but inovations in technology have given us digital controllers such as the ComAp InteliAMF 25 shown to the left of this paragraph. ComAp are a world leader in generator control, load transfer and synchronization technology and their products feature in all ATS, AMF and Synchronized panels we build.

The controller manages the transfer of power by energizing and de-energizing contactors for the mains and generator supply which then passes through a circuit breaker (supply protection) at the distribution board/consumer unit location. The contactors (pictured) are connected together using a mechanical interlock device and an electrical interlock, preventing both contactors from closing simultaneously.

The difference between the ATS and AMF units is that where the ATS unit simply generates a remote start signal to command the generator to start and stop, the AMF unit controls and monitors all generator functions and safety features. It will constantly monitor oil pressure, water temperature and coolant level in addition to the voltage and frequency of the generator supply. This negates the need for an additional electronic control unit to be fitted on the generator.

The full range of ComAp New Technology controls can be monitored and operated remotely via an internet bridge or GSM modem link.