Rockwell Automation 1756-L7x GuardLogix 5570 Controllers - Manual (Page 33)

Rockwell Automation Publication 1756-UM022A-EN-P - November 2012 33
Install the Controller Chapter 2
Uninstall an Energy Storage
Module (ESM) The controllers ship with an ESM installed.
Consider these points before removing the ESM:
• After the controller loses power, either because the chassis power is turned
off or the controller has been removed from a powered chassis, do not
remove the ESM immediately.
Wait until the controller’s OK status indicator transitions from Green to
Solid Red to OFF before you remove the ESM.
• Use the 1756-ESMNSE module if your application requires that the
installed ESM deplete its residual stored energy to 40 μJ or less before
transporting it into or out of your application.
• Once it is installed, you cannot remove the 1756-ESMNRM module from
the controller.
Follow these steps to remove a 1756-ESMCAP(XT), 1756-ESMNSE(XT), or
1756-SPESMNSE(XT) module.
Controller Installed ESM Cat. No.
1756-L7xS controller 1756-ESMCAP
1756-L7xSXT extreme temperature controller 1756-ESMCAPXT
1756-L7SP safety partner 1756-SPESMNSE
1756-L7SPXT extreme temperature safety partner 1756-SPESMNSEXT
IMPORTANT Before you remove an ESM, make necessary adjustments to your program
to account for potential changes to the WallClockTime attribute.
WARNING: If your application requires the ESM to deplete its residual stored
energy to 40 μJoule or less before you transport it into or out of the application,
use only the 1756-ESMNSE(XT) module for the primary controller and the 1756-
SPESMNSE(XT) for the safety partner. In this case, complete these steps before
you remove the ESM.
a. Turn power off to the chassis.
After you turn power off to the chassis, the controller’s OK status indicator
transitions from Green to Solid Red to OFF.
b. Wait at least 20 minutes for the residual stored energy to decrease to 40 μJ or
less before you remove the ESM.
There is no visual indication of when the 20 minutes has expired. You must
track that time period.
WARNING: When you insert or remove the energy storage module while
backplane power is on, an electrical arc can occur. This could cause an explosion
in hazardous location installations.
Be sure that power is removed or the area is nonhazardous before proceeding.
Repeated electrical arcing causes excessive wear to contacts on both the module
and its mating connector.