These Automatic Transfer Switches (ATS) or Manual Transfer Switches (MTS) are Suitable for Use as Service Entrance Equipment (SE) and can be manufactured using either Molded Case or Insulated Case designs.
 

When a Lake Shore Electric Corporation Transfer Switch’s load side is connected to a load, and utility side is connected to the incoming utility service conductors, it can be rated and listed as Suitable for Use as Service Entrance Equipment. This allows a great deal of flexibility to the design engineer in creating an efficient and economical electrical power system.
 

• Provides permanent marking identifying it as a service disconnect.
• Provides overcurrent protection for each ungrounded service conductor.
• Provides a means of disconnecting the bonding of the grounded conductor.
• Provides clear indication of the position of disconnect.

This application allows for the elimination of separate service disconnect in series with the transfer switch. The cost savings can be significant.
 

• Additional equipment is not needed.
• Interposing cable and conduit are eliminated.
• Labor for equipment mounting is reduced.
• Labor for interposing cable and conduit is eliminated.

The logical application of service entrance equipment is where the alternate power supply is capable of accepting the entire load and/or the placement of the ATS is placed in a readily accessible location consistent with Article 230 of the National Electric Code (NEC).
 

Section 230-2 of the NEC clearly identifies emergency systems, legally required standby systems, optional standby systems and parallel power production systems as separate services.