A complete treatment of ANSI/NEMA a michael kors handbags clearancend safety agency standards is well beyond the scope of this article. For help in selecting the appropriate coil housing for the exposure expected, the manufacturer's literature or application engineering department should be consulted.

 Electrical ratings and performance

 In addition to voltage and frequency, specifications include holding current and inrush current as well as wattage.

 Inrush is the current tMichael Kors outlet hat prevails immediately after the switch is closed, but before the plunger has completed its travel.

 The current draw of ac coils is determined by coil impedance, not resistance alone. Impedance results from a combination of resistance and inductive reactance.

 Inductive reactance is a measure of how much the flow of current is inhibited as a result of the rapidly reversing magnetic fields associated with an alternating current. Inductive reactance increases both with freabercrombie and fitch clothingquency and with the amount of iron in the core of the solenoid. This is why current draw is higher at 50 Hz than at 60 Hz. It also explains why inrush current is often twice as high as holding current.

 When the switch is first closed, the plunger is at some distance from the stationary pole, so that an air gap greatly limits the magnetic field strength. After the plunger reaches its final position, the air gMichael Kors online  ap is closed and the effectiveness of the iron in the core is much greater.

 This causes the inductive reactance, and therefore the impedance, to be much higher after the plunger completes its flight and solidly contacts the stationary pole.

 Current in a dc solenoid depends only on resistance, so inrush and holding current are no different. This is why the MOPD rating is lower with direct current; there is no benefit of initiaabercrombie and fitch outlet l over-current to assist in lifting the plunger.