Mitsubishi Electric FR-E720-0.4K Instruction Manual page 19

(1) Control circuit common terminals (SD, 5, SE)
• Terminals SD, SE and 5 are common terminals for I/O signals. (All common terminals are isolated from each other.) Do not
earth them. Avoid connecting the terminals SD and 5 and the terminals SE and 5.
• Terminal SD is a common terminal for the contact input terminals (STF, STR, RH, RM, RL, MRS, RES) and the pulse train
output (FM). The open collector circuit is isolated from the internal control circuit by photocoupler.
• Terminal 5 is a common terminal for the frequency setting signals (terminal 2 or 4). It should be protected from external
noise using a shielded or twisted wire.
• Terminal SE is a common terminal for the open collector output terminal (RUN, FU). The contact input circuit is isolated
from the internal control circuit by photocoupler.
(2) Wiring instructions
• It is recommended to use the wires of 0.3mm
• The maximum wiring length should be 30m (200m for terminal FM).
• Do not short terminals PC and SD. Inverter may be damaged.
• When using contact inputs, use two or more parallel micro-signal contacts or
twin contacts to prevent contact faults since the control circuit input signals are
micro-currents.
• To suppress EMI, use shielded or twisted cables for the control circuit terminals
and run them away from the main and power circuits (including the 200V relay
sequence circuit). For the cables connected to the control circuit terminals,
connect their shields to the common terminal of the connected control circuit terminal. When connecting an external power
supply to terminal PC, however, connect the shield of the power supply cable to the negative side of the external power
supply. Do not directly earth (ground) the shield to the enclosure, etc.
• Always apply a voltage to the fault output terminals (A, B, C) via a relay coil, lamp, etc.
• When using an external power supply for transistor output, note the following points to prevent a malfunction caused by
undesirable current.
Do not connect any terminal SD on the inverter and the 0V terminal of the external power supply (when the sink logic is
selected).
Do not connect terminal PC on the inverter and the +24V terminal of the external power supply (when the source logic is
selected).
Do not install an external power source in parallel with the internal 24VDC power source (connected to terminals PC and
SD) to use them together.
Refer to Chapter 2 of the Instruction Manual (Applied) for the detail.
2 2
to 0.75mm gauge for connection to the control circuit terminals.
Wiring
Micro signal contacts Twin contacts
2
15