Entering MIL-HDBK-217 Switching Devices
The following table describes the part parameters required for switching devices when a MIL-HDBK-217 model is selected for the calculation. The FN2 models support all but the Keyboard subcategory of switching devices. The FN1 model does not support any of the following subcategories: Keyboard, Other, and Rocker or Slide.
Parameter
Type
Description
Quality Level
Choice List
The quality screening level used in the manufacturing of the device. Choices are:
Mil-Spec
Commercial
Type
Choice List [Parts Count also]
For FN2 models, required only for the Circuit Breaker subcategory. For FN1 models, required for the following subcategories: Toggle or Pushbutton, Rotary, and Circuit Breaker.
The type of device. Choices vary based on subcategory.
Actuation Differential
Choice List [FN1 only]
Required only for the Basic Sensitive subcategory.
The actuation differential. Choices are:
<=0.002 inches
0.002 inches
# of Active Contacts
Integer [FN1 only]
Required only for the following subcategories: Basic Sensitive, Rotary, and Thumbwheel.
The number of conductive elements in the connector that mate with other elements for the purpose of transferring electrical energy.
Contact Form
Choice List
Required only for the following subcategories: Circuit Breakers and Toggle or Pushbutton.
The number and type of active conducting contacts. Many different choices are available, including SPDT, 3PST, and more.
Load Type
Choice List
Not required for the Circuit Breaker subcategory.
The type of load connected external to the device. Choices are:
Lamp
Inductive
Resistive
Application
Choice List
Required only for the Circuit Breaker category.
The application in which the circuit breaker is used. Choices are:
Protection Only
Power On/Off
Cycling Rate
Real [FN1 only]
Not required for the Circuit Breaker subcategory.
The average number of switching cycles per day.
[Current Parameters]
Real (Amps)
Not required for the Circuit Breaker subcategory.
For more information, see Current Parameters.
[Temperature Parameters]
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For more information, see Basic Temperature Parameters.
[Derating Parameters]
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For more information, see Derating Parameters.