3-15Use the PGND cable provided with the switch to connect the grounding strip in the equipment room.Otherwise, the grounding effect may not be ensured, which easily causes damage to the switch.Installing a Power Modulez The following section describes how to install a power module for only the S5500-28F-EI Ethernetswitches.z Before installation and removal, make sure that no power cord is connected to the power module.The installation/removal procedure of the PSR150-A and PSR150-D is similar. This manual takes thePSR150-A as an example to introduce the installation and removal of the power module.Installing the Power ModuleThe installation procedure is as follows:Step1 Wear an ESD-preventive wrist strap, ensure a good skin contact and make sure that theESD-preventive wrist strap is properly grounded.Step2 Take the power module from the package and check that the power module model is as required.Step3 Face the slot into which the power module is to be inserted.Step4 Insert the power module with the upside up. (if you insert it with the upside down, the insertion is notsmooth because of the specific structure design of the power module and slot). Grasp the handle of themodule with one hand and hold the module bottom with the other, and then slide the module slowlyalong the guide rails into the slot (see callout 1 in Figure 3-20).Step5 Fasten the captive screw on the power module clockwise with a Philips screwdriver until the powermodule is fixed into the chassis (see callout 2 in Figure 3-20).