Rockwell Automation 2500 CENTERLINE Motor Control Centers Installation Manual - Manual (Page 96)

96 Rockwell Automation Publication 2500-IN001C-EN-P - April 2014
Glossary
Plug-in units Removable units with line connections made via unit bus line stabs. Plug-in units
include withdrawable units. Sometimes referred to as withdrawable or removable
units.
Protective earth conductor (PE) Protective circuit busbar. Sometimes referred to as earth bar.
Released position Plug-in unit operating position in which line, load, control, network, and
protective earth (PE) connections are disengaged and the unit is removed from
the column. For more information refer to
Chapter 6, Install and Remove Units .
Shipping block A single column packaged for transport or multiple columns joined and
packaged together at the manufacturing site for ease of transportation. Shipping
blocks cannot be separated at the installation site. Sometimes referred to as
shipping splits.
Skilled person “Person with relevant education and experience to enable him or her to perceive
risks and to avoid hazards that operation or maintenance of a product can create.”
IEC 60204-1, 3.52 and IEV 195-04-01.
Stabs Assembly on the back of a unit that is used to make line and load connections.
(See
Withdrawable Units on page 60 ).
Test position Plug-in unit operating position in which the control, network, and protective
earth (PE) connections are engaged, and line and load connections are isolated.
For more information refer to
Chapter 6, Install and Remove Units .
Trunk line Main DeviceNet communication cable within the motor control center.
Unit An arrangement of power and/or control devices that are housed together and
inserted into a column. A unit can be used to distribute power or control a
remote device. The size of units is described by module space.
Unit main switch Disconnecting means for a unit within a motor control center. Available in two
types: circuit breaker or fused disconnect.
Withdraw lever Mechanism used to insert and remove withdrawable units. The withdraw lever is
used to select an operating position (inserted, test, disconnected, and withdrawn)
and has mechanical detents so the lever is securely in position. (See
Selecting an
Operating Position on page 62 ).
Withdrawable unit Unit where line, load, control, network and PE connections are made with stabs
or connectors. Withdrawable units are inserted and removed by using the
withdraw lever.