Industrial control equipment demands a momentary overload capacity of three to eight times normal capacity. This is most prevalent in solenoid or magnetic contactor applications where inrush currents can be three to eight times as high as normal sealed or holding currents but still maintain normal voltage at this momentary overloaded condition. Distribution transformers are designed for good regulation up to 100 percent loading, but their output voltage will drop rapidly on momentary overloads of this type making them unsuitable for high inrush applications. Industrial control transformers are designed especially for maintaining a high degree of regulation even at eight times normal load. This results in a larger and generally more expensive transformer. For a complete listing of ACME industrial control transformers, refer to Section V in the ACME catalog.
How can the problem be remedied : No residual magnetism, reversed field connection and high resistance of field circuit are responsible for the failure of build up process of a dc generator. The factors are explained below: No residual magnetism: For the starting build up process requires some residual magnetism in the magnetic circuit then no voltage will be generated that can produce current flow through field circuit. Reversed field connection: The voltage induced inside the coil of field circuit due to residual magnetism that can permit the flow of current. For the following direction of this flux will be created and the direction of this flux will be same direction as the residual flux. If the field connections are reversed the lines of flux produced by current flow will oppose the residual flux, as a result generate voltage will decrease rather than increase. So voltage build up process failed. Field circuit resistance too high: A field
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