Rockwell Automation FlexPak Plus DC Drive - Manual (Page 16)

3:6
isolation transformer, thus
reducing or eliminating possible
damage to solid state
components.
D With an isolation transformer, the
Drive is free of plant power
system grounds, providing
electrical isolation for the Drive
from those grounds. Damaging
currents may be avoided in
instances where the DĆC output
is accidentally grounded or
where the DĆC motor circuits go
to ground.
Reliance offers a series of isolation
transformers suitable for use with
the FlexPak Plus Drive. Refer to
Table 2Ć2.
Motor OverloadProtection
Reliance utilizes a DĆC motor
thermostat for motor thermal
overload protection. The thermostat
is brought out through the motor
terminal box as leads P1 and P2.
These two leads must be wired to
the Controller terminals 32 and 132.
The thermostat leads can be run
with the motor armature and field
power wiring.
If an additional inverse time
overload is added, its normally
closed contact should be wired in
place of the motor thermostat and
connected to the controller at
terminals 32 and 132, or in series
with the motor thermostat when
both are used.
NOTE: The Drive will not start if the
circuit between 32 and 132 is not
made.
Armature Loop Contactor
Sequencing
WARNING
THE FLEXPAK PLUS DĆC
DRIVE MUST EMPLOY A CONĆ
TACTOR IN THE MOTOR ARĆ
MATURE LOOP FOR POSIĆ
TIVE DISCONNECT OF THE
MOTOR FROM THE DRIVE IN
A STOP CONDITION. AN INĆ
ADVERTENT START CAUSED
BY NOISE OR DRIVE COMPOĆ
NENT FAILURE MAY CAUSE
UNEXPECTED MOTOR AND
MACHINE MOVEMENT IF A
CONTACTOR IS NOT USED.
FAILURE TO OBSERVE THIS
PRECAUTION COULD REĆ
SULT IN BODILY INJURY.
In all cases, the Drive must have an
armature loop contactor to
disconnect the motor from the
Controller on a Stop.
When the Armature Loop Contactor
is not supplied by Reliance, its
ON/OFF" sequence must be
integrated into the sequence control
of the regulator just as when the
Contactor is supplied by Reliance.
The "ON" sequence requires that
the contactor is closed and
approximately 8 milliseconds later
the Drive CR Relay is energized to
release the regulator. The OFF"
sequence requires that the Drive CR
Relay first clamps the regulator
(dropĆout of the CR Relay is about 8
milliseconds) and then the
contactor is allowed to dropĆout.
The M Contactor Adapter Kit M/N
14C276 is to be used to connect the
Contactor to the Regulator to
incorporate this sequencing
function.
Refer to Figure 3.4 for
Regulator/Contactor Start/Stop
timing.
The Contactor that is used must
have a 25VDC coil and a maximum
current draw of 150 milliĆamps. A
220 MFD capacitor must be
connected in parallel with the
contactor coil for dropĆout timing.
(See Figure 3.4)
Refer to Figure 3.5 and Figure 3.6
for M Contactor connection when
the Contactor is not supplied by
Reliance.