LEESON Micro Series Compact Inverters - Manual (Page 36)

14.0 CONTROL WIRING
14.1 GENERAL
14.1.1 KEYPAD CONTROL
The drive can be controlled by the keypad or by control devices wired to the terminal strip. The drive will
run from the keypad “out of the box”, requiring no connections to the terminal strip. Refer to Section 13.0
- KEYPAD CONTROL .
14.1.2 CONTROL WIRING VS. POWER WIRING
External control wiring MUST be run in a separate conduit away from all other input and output power
wiring. If control wiring is not kept separate from power wiring, electrical noise may be generated on the
control wiring that will cause erratic drive behavior . Use twisted wires or shielded cable grounded at the
drive chassis ONLY. Recommended control wire is Belden 8760 (2-wire) or 8770 (3-wire), or equivalent.
Torque the control terminals to 2 lb-in (0.2 Nm). Be careful not to overtorque the control terminals, as
this will cause damage to the terminal strip . This is not covered under warranty and can only be repaired by
replacing the control board .
14.1.3 TB-2: CIRCUIT COMMON
The TB-2 terminals are used as circuit common for the start/stop, forward/reverse, input select,
local/remote, analog input, and analog output functions . There are three TB-2 terminals available on the
terminal strip, and they are all internally connected to each other on the main control board . If necessary
TB-2 may be connected to chassis ground .
NOTE: TB-2 MUST be connected to chassis ground when using serial communications .
14.1.4 SURGE SUPPRESSION ON RELAYS
Current and voltage surges and spikes in the coils of contactors, relays, and solenoids, etc, near or
connected to the drive, can cause erratic drive operation . Therefore, a snubber circuit should be used on
coils associated with the drive . For AC coils, snubbers should consist of a resistor and a capacitor in series
across the coil. For DC coils, a free-wheeling or flyback diode should be placed across the coil. Snubbers are
typically available from the manufacturer of the device .
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