PowerTec 2000C Instruction Manual page 42

FAULT RELAY
Figure 20: Adding a FAULT relay to a
Model 2000C or Model 3000C.
A 48VDC relay may be connected to the POWER-
TEC Brushless DC motor control in the manner shown in
Figure 20. Using an auxiliary relay makes fault contacts
available to 120VAC control circuits (the fault output of
the board is the output transistor portion of an optical
coupler, and the optical coupler can only operate direct
current circuits up to 50VDC at 50 milliamps). The diode
around the coil of the fault relay is for surge protection.
The fault circuits are designed to be fail safe. If there
is no fault, the relay is energized. If the relay should fail for
any reason, the relay will be off, indicating a fault.
Figure 21: Obtaining an ENABLE indication.
© copyright 1992, 1996 by Powertec Industrial
Motors
ENABLE RELAY
On the POWERTEC Models 2000C and 3000C
there is a way to obtain an enable relay output which
combines the functionsof the RUN and the FAULT relays.
The RUN relay is pulled in by the application of
+24VDC to TB2 terminal 4. The RUN relay will stay on
as long as there is a sufficiently positive voltage on that
terminal. The RUN relay does not drop out when a trip
occurs. It only drops out when both terminals 4 and 5 on
TB2 are open.
The FAULT relay pulls in when there are no faults
(i.e., when the bus is charged up after application of power
or after a previous fault is reset by pressing the STOP
button). It only drops out after a trip occurs.
Neither the RUN nor the fault tells the user by itself
that the control is actually in an operational state, but the
combination of the two, when both are ON, says that the
control is on and that there are no faults. This circuitry will
shut off when the RUN circuit is dropped, even if the
control is decelerating in RAMP STOP.
Figure 21 illustrates the wiring and connections to
connect an ENABLE relay to the Model 2000C. The
maximum current is 50mA. The diode around the coil must
be installed.
ZERO SPEED RELAY
Figure 22: Connecting a ZERO SPEED relay. Note
that the relay coil is 24VDC, so current should be
kept low.
A 24VDC relay may be connected from the +24VDC
unswitched supply to the zero speed output terminal TB2
terminal 1 (see Figure 22).
The zero speed output is an open collector transistor
with the collector connected to TB2 terminal 1 and the
emitter to control common. The Zero Speed relay may be
used to indicate that the motor is actually running.
The relay coil current must be limited to a maximum
of 50mA. The diode around the relay coil must be installed
to prevent any high voltage transients at turn-off from
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