3.6 Ladder Diagrams
3.6.1 Library of Standard Ladder Diagrams
The SAMMS-LV library of more than 70 ladder diagrams covers most standard motor control applications. Table 3.3 lists the standard control circuits and the input and output assignments for the library. You can use the library with the following starter types:
•across-the-line, non-reversing
•across-the-line, reversing
•two-speed, two winding
•two-speed, one-winding, constant or variable torque
•two-speed, one-winding, constant horsepower
•reduced-voltage, autotransformer (size 2 through 4)
•reduced-voltage, autotransformer (sizes 5 and 6)
•full-voltage, part winding
•wye-delta, open transition
•wye-delta, closed transition
For each starter type, the library includes seven control types:
•local two-wire
•local three-wire
•local three-wire, remote two-wire
•local two-wire, remote two-wire
•local three-wire, remote three-wire
•remote two-wire
•remote three-wire
SAMMS-LVE has seven preloaded circuits (ladder diagrams) for use with across-the-line (FVNR) applications. SAMMS-LVX may be used with any of the circuits.
For details on the library of standard ladder diagrams, refer to the SAMMS Standard Circuit Manual.
3.6.2 Custom Ladder Diagrams
For special motor control applications not covered by the library of standard ladders, you can construct custom ladder dia- grams using the input and output devices and their associated symbols for the SAMMS-LV device. Siemens personnel can build these custom ladder diagrams or you can build your own. You can purchase an optional IBM PC-compatible software package to develop custom ladder diagrams for special control applications. The package also includes a library of standard symbols. The package enables you to reconfigure existing SAMMS-LV devices to meet changing plant needs. Refer to the Custom Software Manual for the SAMMS device, Bulletin CP 3291.
