Rockwell Automation DC3N DC Drive User Guide, 1/4-2HP-115/230 VAC User Manual

Page 28

Starting and stopping using inhibit terminals

Operation

ATTENTION:

Starting and stopping with the inhibit terminal pins does not

disconnect AC power in the stop position. A hardwired AC power
disconnection switch must be mounted in close proximity to the operator’s
start/stop controls. This is required, as the DC3 drive does not have an armature
loop contactor. A single fault like a power device short may cause motor
rotation when in the stop mode. The user is responsible for assuring safe
conditions for operating personnel by providing suitable guards, audio or visual
alarms, or other devices. Failure to observe these precautions could result in
bodily injury.

Open or short the INHIBIT terminals to coast the motor to minimum or zero speed
(see Figure 10 for INHIBIT terminal location). Reopen the INHIBIT terminals to
accelerate the motor to set speed. An option is to install a single-pole, single-
throw switch across the INHIBIT terminals (Figure 11).

Twist inhibit wires and separate them from other power-carrying wires or sources
of electrical noise. Use shielded cable if the inhibit wires are longer than 18 inches
(46 cm). If shielded cable is used, ground only one end of the shield to earth
ground. Do not ground both ends of the shield. See Shielding Guidelines on
page 8.

Figure 10. INHIBIT Terminals and Jumper Location

J501

J502

INHIBIT

Terminals

NOTE: INHIBIT
TERMINALS ARE AT
THE SAME VOLTAGE
POTENTIAL AS THE
AC LINE INPUT