Wiring Precautions - Mitsubishi Electric 800 Series Hardware Instruction Manual

• In the source logic, terminal PC is a common terminal for the contact input terminals (STF, STR, STP (STOP), RH, RM,
RL, JOG, RT, MRS, RES, AU, CS). The open collector circuit is isolated from the internal control circuit by photocoupler.
• Terminal 5 is a common terminal for the frequency setting terminals (1, 2, and 4) and the analog output terminals (AM and
*2
CA ). It should be protected from external noise using a shielded or twisted cable.
• Terminal SE is a common terminal for the open collector output terminals (RUN, SU, OL, IPF, and FU). The contact input
circuit is isolated from the internal control circuit by photocoupler.
*1 Terminal FM is provided in the FM-type inverter.
*2 Terminal CA is provided in the CA-type inverter.
 Signal inputs by contactless switches
The contact input terminals of the inverter (STF, STR, STP (STOP), RH, RM, RL, JOG, RT, MRS, RES, AU, and CS) can be
controlled using a transistor instead of a contact switch as follows.
External signal input using transistor
2.6.5

Wiring precautions

• It is recommended to use a cable of 0.3 to 0.75 mm
• The wiring length should be 30 m (200 m for terminal FM) at the maximum.
• Use two or more parallel micro-signal contacts or twin contacts to prevent contact faults when using contact inputs since
the control circuit input signals are micro-currents.
Micro signal contacts
• 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 200 V 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 (A1, B1, C1, A2, B2, C2) via a relay coil, lamp, etc.
54
2. INSTALLATION AND WIRING
2.6 Control circuit
+24 V
STF, etc.
Inverter
SD
(sink logic)
Twin contacts
PC
STF, etc.
External signal input using transistor
(source logic)
2
for the connection to the control circuit terminals.
Inverter
+24 V
R