Rockwell Automation 150 MNL/SMC DIALOG+/APP-PROD GUIDE - Manual (Page 197)

Glossary-10
• Guarded Machine – (NEMA Standard) is an open machine in which all
openings giving direct access to live metal or rotating parts (except smooth
rotating surfaces) are limited in size by the structural parts or by the screens,
baffles, grills, expanded metal or other means to prevent accidental contact
with hazardous parts. Openings giving direct access to such live or rotating
parts shall not permit the passage of a cylindrical rod 0.75 inch in diameter.
• Open Externally Ventilated Machine – is one which is ventilated by means
of a separate motor driven blower mounted on the machine enclosure. This
machine is sometimes known as a blower-ventilated or a force-ventilated
machine.
• Open Pipe Ventilated Machine – is basically an open machine except that
openings for admission of ventilating air are so arranged that inlet ducts or
pipes can be connected to them. Air may be circulated by means integral with
the machine or by means external to the machine (separately forced
ventilated).
• Semiguarde – is an open machine in which part of the ventilating openings in
the machine, normally in the top half, are guarded as in the case of a”guarded
machine” but the others are left open.
• Splashproof – is an open machine in which the ventilating openings are so
constructed that successful operation is not interfered with when drops of
liquid or solid particles strike or enter the enclosure at any angle not greater
than 100 degrees downward from vertical.
• Weather-protected Machine – is an open enclosure divided into two types:
1. Type 1 – enclosures have ventilating passages constructed to minimize the
entrance of rain, snow, airborne particles and prevent passage of a 0.75
inch diameter cylindrical rod.
2. Type 2 – enclosures provide additional protection through the design of
their intake and exhaust ventilating passages. The passages are so
arranged that wind and airborne particles blown into the machine can be
discharged without entering directly into the electrical parts of the
machine. Additional baffling is provided to minimize the possibility of
moisture or dirt being carried inside the machine.
Operator Interface Device A terminal from which an operator can monitor and possibly affect aspects of the
machine or process control.
Output Device 1. For a programmable controller, any machine/process load device (such as
solenoid or motor starter) of a controller output circuit.
2. For a computer, a CRT terminal or printer.
Overload Capacity The ability of the drive to withstand currents beyond the systems continuous rating.
It is normally specified as a percentage of full load current for a specified time
period. Overload capacity is defined by NEMA as 150% of rated full load current
for one minute for Standard Industrial DC Motors.