Rockwell Automation 1395 DC Drive, 800-1250 Hp, FRN 5.XX-9.30 User Manual
Page 28
Chapter 2
Hardware Description
2-15
Relay Logic
Main Contactor (M1) Control – Figure 2.13 illustrates the hardware
associated with the control of the coil voltage applied to the Main DC
contactor M1. The coil voltage originates at an external 115VAC source.
The source voltage may be interrupted before being input to the drive at
TB5-9 and -10 by the use of externally controlled contacts. These external
contacts may include an external master coast stop, PLC controlled
contacts, permissive contacts, etc. Main contactor M1 coil voltage is
controlled within the 1395 through the Power Stage Interface when M1 is
energized. This signal is rectified and optically isolated to produce a 5V
logic signal CVERIFY which is sent to the Main Control Board.
Pilot Relay (PR) Control – K2 and K3 contacts on the PSI Board in series
with the 115VAC Coast Stop input to the drive, control coil voltage to the
Pilot Relay.
ECOAST Stop – The “ECOAST Stop” as defined and illustrated, is a
contingency circuit designed to stop the motor in event of a malfunction in
the solid state interface drive software.
When an ECOAST Stop is initiated, the DC loop contactor is de-energized
and the motor will coast to a stop unless the drive is equipped with
optional dynamic braking circuitry.
The optional dynamic braking circuitry is designed to develop 150% –
200% of rated motor torque for braking when an ECOAST Stop is
initiated. Braking torque decreases with speed. This option is not
recommended for repetitive operation.
Relay K2 on the Power Stage Interface is the ECOAST Stop relay and is
controlled by +24VDC. As shown in Figure 2.13, +24VDC from the
Power Stage Interface is connected to TB3-12 and -11. At this point, an
external (dry) 24VDC ECOAST stop contact could be used to control the
application of 24VDC to K2 through TB3-9. TB3-12 and -10 should
always be jumpered together to provide a return path for 24VDC. If an
external 24VDC ECOAST Stop contact is not used, then TB3-9 and -11
must be jumpered.
In addition to the 24VDC ECOAST Stop, there is an 115VAC ECOAST
Stop circuit which is also provided as standard in the 1395. 115VAC
enters the power stage interface from TB5 and is distributed to TB3-4.
Between TB3-4 and -5, an external (dry) ECOAST Stop contact may be
connected. If an external 115VAC ECOAST stop circuit is not used,
TB3-4 and 5 must be jumpered. 115VAC is returned to the Power Stage
Interface from TB3-5 and sent to contacts of K2. From here it proceeds to
the contacts of K3 on the Power Stage Interface. The 115VAC ECOAST
Stop Signal is also sent to an isolation circuit which converts the 115VAC
to a +5VDC control Signal ECOAST which is sent to the Main Control
Board.
Main Control Relay – K3 on the Power Stage Interface is the main
control relay which controls turn on voltage to the coil of the pilot relay
PR. K3 is controlled by logic signals from the Main Control board
entering the Power Stage Interface through ribbon connector J9. The two
signals which control K3 are the SYSTRIP and the DCPILOT signals. In
order for K3 to energize PR, there must be no system fault and there must
be a DC pilot relay turn-on command. If both these conditions are met, K3
is energized, and PR is in turn energized.