Machines For Fashion Business

sewing machines for business in nigeria, like the Juki or brother industrial, are they converted so that you can you use it manually when there's no light! 

And example is the type shown below, is there are way to use it manually when there is no light and then use it with electricity. 

Any help help or insight will be helpful

http://www.joyssewingmachines.co.uk/images/industrialwithjoyslogosmall_000.jpg