2-13
Table 2.8 Symbols, Names and Functions of the Control Circuit Terminals (Continued)
Classifi-
cation
Symbol Name
Functions
- These low level analog signals are especially susceptible to the external noise effects.
Route the wiring as short as possible (within 20 m) and use shielded wires. In principle,
ground the shielded sheath of wires; if effects of external inductive noises are con-
siderable, connection to terminal [11] may be effective. As shown in Figure 2.5, ground
the single end of the shield to enhance the shield effect.
- Use a twin-contact relay for low level signals if the relay is used in the control circuit.
Do not connect the relay's contact to terminal [11].
- When the inverter is connected to an external device outputting analog signals, the
external device may malfunction due to electric noise generated by the inverter. If this
happens, according to the circumstances, connect a ferrite core (a toroidal core or
equivalent) to the device outputting analog signals or connect a capacitor having the
good cut-off characteristics for high frequency between control signal wires as shown
in Figure 2.6.
- Do not apply a voltage of +7.5 VDC or higher to terminal [C1]. Doing so could damage
the internal control circuit.
Analog i
nput
Figure 2.5 Connection of Shielded Wire
Figure 2.6 Example of Electric Noise Reduction
Potentiometer
1 k to 5 k
Ω
