Installation
4-10
L
MA9300PLC EN 1.4
4.2.1.2 Isolation
The controllers have an electrical insulation (isolating distance) between the power terminals and
the control terminals as well as to the housing:
• Terminals X1 and X5 have a double basic insulation (double isolating distance, safe electrical
isolation to VDE0160, EN50178). The protection against contact is ensured without any
further measures.
• The control inputs and outputs of all controllers are electrically isolated.
Danger!
• Terminals X3, X4, X6, X7, X8, X9, X10 have a single basic insulation (single isolating
distance).
• Protection against contact in the event of fault is ensured only by additional measures.
• If an external voltage supply (24V DC) is used, the insulation level of a controller depends on
the insulation level of the voltage source.
reinforced insulation
single basic insulation
Fig. 4-6 Basic insulation in the controller
4.2.1.3 Replacement of defective fuses
Replace defective fuses with the prescribed type only when no voltage is applied. (^ 3-7)
• For single drives, the controller carries a hazardous voltage up to three minutes after mains
disconnection.
• In a DC-bus connection, all controllers must be inhibited and separated from the mains.
4.2.1.4 Mains disconnection
Make a safety disconnection between the controller and the mains only via a contactor at the input
side.
• Please observe that all drives connected to the DC bus must be inhibited.