LEESON SM-Basic Series Sub-Micro Inverters (Obsolete) - Manual (Page 14)

10
10.0 CONTROL WIRING
10.1 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 rated for 300 VDC minimum (do not ground the shield).
10.2 SURGE SUPPRESION ON RELAYS
Current and voltage surges and spikes in the coils of contactors, relays, and solenoids, near or connected
to the drive, can cause erratic drive operation. Snubbers should be used on any coils associated with
the drive. For AC loads, snubbers should consist of a resistor and a capacitor in series across the coil.
For DC loads, a free-wheeling or flyback diode should be placed across the coil.
10.3 START/STOP CONTROL
There are various control schemes that allow for 2-wire and 3-wire Start/Stop circuits. Refer to the
wiring diagrams in Section 11.0 - SM-Basic CONTROL WIRING DIAGRAMS.
10.4 SPEED REFERENCE SIGNALS
SPEED POT Connect the wiper to terminal TB-5, and connect the high and low end leads to
terminals TB-6 and TB-3, respectively. The speed pot can be 5k
Ω up to 10kΩ.
0-10 VDC Wire the positive to terminal TB-5 and the negative to terminal TB-3. The 0-10
VDC signal must be isolated, as the control terminals are at line voltage potential.
DO NOT connect the low side of the speed pot or 0-10 VDC signal to ground.
WARNING!
Hazard of electrical shock! The SM-Basic control terminals are not isolated from line voltage!
Line voltage is present between the control terminals and ground. Do not touch!
Disconnect input power and wait three minutes before making connections to the control terminals.
Devices (such as switches, pushbuttons, potentiometers, relays, etc) and wiring connected to the
control terminals are hot to ground and must have an insulation rating of at least 240 Vac or a
dielectric rating of at least 1500 volts to prevent damage to equipment and/or injury to personnel.