Why is there door latches when its an automatic door?

"Latches" please Give more detail.

The latches I assume you are referring to the handles.

The latches or handles are on the door(s) because.

Automatic doors need to have a secondary method of operation.

Electricity is not 100% reliable. If the power went out in the building

people would need to have a way to open the doors.

Most city building codes mandate such.

There can be many reasons to latch an automatic door:

1) Security - usually allows free egress and calls for access control or a time zone that controls when the door unlocks for the days business.

2) Seperation - This could be for enviromental control (areas that only trained personal can go for safety) or clean rooms are commonly designed with air pressure that will prevent dirt from entering and a latch is called for to prevent the door from opening.

3) Safety- authorized personal are the only ones allowed in the area to perform tasks necessary.

Building codes (NFPA 101 life safety) only addresses not entrapping people in a buiding, so if you lock them out that is acceptable, but free egress out of the buiding is always a major concern, and a code!