PLAN No. 1078. TESTING
Nearly all electrical equipment is tested before it leaves the factory. That is to say, it is subjected to electrical and mechanical conditions similar to those under which it must operate in practice, so that its performance under such conditions may be predetermined. This is necessary to insure that the product which leaves the factory will not develop faults after it is in service. Where machines or devices are of large capacity, each is tested individually. Where the output comprises a large number of small, identical machines, as for example, automobile starting motors, or circuit-breakers, only one or a few out of each order which passes through the shop are subjected to test.