Siemens SIMATIC S5-90U System Manual page 56

Installation Guidelines
Mounting the PS 931 Power Supply Module
Hook the power supply module onto the standard mounting rail.
Press the module down firmly until the slide snaps onto the rail.
Removal:
Turn off the 115 V/230 V AC power supply.
Loosen the connections between the PLC and the power supply module.
Using a screwdriver, press down on the slide on the bottom of the module.
Swing the module up and out of the standard mounting rail.
How to Connect Bus Units to the S5-95U
Bus units are also mounted on a standard mounting rail. Mount the bus units in the same way you
mounted the controller or a power supply module.
There are small hooks on the sides of the bus units that interlock them.
Mounting the bus units
Hook the bus unit onto the standard mounting rail.
Press the bus unit down firmly until the slide audibly snaps into place.
Pull the flat ribbon cable connector (top left on the bus unit) out of its holder.
Plug the connector into the receptacle on the right side of the controller or into the receptacle of
the adjacent bus unit on the left side (see Figure 3-8).
Removing the bus units
Loosen the connections (flat ribbon cable) to the adjoining devices.
Using a screwdriver, press down on the slide.
Swing the bus unit up and out of the standard mounting rail.
3-8
S5-90U/S5-95U
EWA 4NEB 812 6115-02b