Rockwell Automation 150 MNL/SMC DIALOG+/APP-PROD GUIDE - Manual (Page 192)

Glossary-5
• NEMA Type 9 – An enclosure designed for a hazardous location, Class 2
Groups F and G per the National Electrical Code. The atmosphere in which
this control must operate will contain carbon black, coal or coke dust, flour,
starch, or grain dust.
• NEMA Type 12 – Designed for industrial use. The enclosure is intended fo
use in applications where it is desirable to exclude such materials as cooling
oil, seepage, dust, lint, fibers and filings. This is normally a non-ventilated
enclosure with an oil-resistant synthetic gasket between the case and the cover.
The cover is hinged to swing horizontally and is held in place with suitable
fasteners which require the use of a tool.
• JIC – Joint Industry Conference enclosures are similar in specifications to th
NEMA Type 4 and Type 12 enclosures. The most obvious difference is the
way the seal is obtained. They are suitable for the abuse of the standard NEM
Type 4 and NEMA Type 12 enclosures.
• Hazardous Location–- Enclosures normally meet some or all of the following
specifications: Class I, Group D; Class II, Groups E, F, and G; NEMA Type 7
and NEMA Type 9.
1. Class I, Group D – is designed to meet the application requirements of the
NEC and is in accordance with the latest specifications of Underwriters
Laboratories, Inc., for locations having atmospheres containing gasoline,
hexane, naptha, benzine, butane, propane, alcohol, acetone, benzol,
lacquer solvent vapors or natural gas.
2. Class II, Group E, F, and G – is designed to meet the application
requirements of the NEC and is in accordance with the UL requirements
for atmospheres containing metal dust, including: aluminum, magnesium,
and their commercial alloys; and other metals of similar hazardous
characteristics: carbon black, coal or coke dust, flour, starch, or grain
dusts.
Factory Wiring 1. Wiring completed before the product was shipped from the factory in which it
was built.
2. Contrasted with Field Wiring.
Fault Any malfunction that interferes with normal system operation.
Floating Ground A circuit whose electrical common point is not at earth ground potential or the
same ground potential as circuitry it is associated with. A voltage difference can
exist between the floating ground and earth ground.
Forc The tendency to change the motion or position of an object with a push or pull.
Force is measured in ounces or pounds.
Frame Size The physical size of a motor, usually consisting of NEMA designed “D” and “F”
dimensions at a minimum. The “D” dimension is the distance in quarter inches
from the center of the motor shaft to the bottom of the mounting feet. The “F”
dimension relates to the distance between the centers of the mounting feet holes.