ABB CL Series Applications Manual page 59

Installation
CL-LMR...
CL-LMT...
56
CL-LEC.CI0
00
E+ E–
U = 300/500 V
e
CL-LER.18AC2
Figure 35: Connecting remote expansion units to CL basic unit
h
The terminals "E+" and "E-" of the CL-LEC.CI000 are
protected against short-circuits and polarity reversal.
Functionality is only ensured if "E+" is connected with
"E+" and "E-" with "E-".
1SVC 440 795 M0100
E+ E–
CL-LER18...
CL-LET20...