Mitsubishi A2 Serie Manuel Du Materiel page 73

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2 Simple Application Controllers
11.3.3 Applicable Error checks
1) If an External power supply error (M16) occurs:
Check the "+" and "-" connections to the AL2-2DA for correct wiring and installation
procedures.
Check the original Power Supply source for 24V DC operation.
AL2-2DA (AL2-14MR-*, AL2-24MR-*) 11
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