Baldor MicroFlex e100, Installation Manual

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Basic Installation 3-21 MN1942
3.5.5 Thermal switch connection
You might wish to wire the motor’s thermal switch contacts (normally closed), using a relay, to a
digital input on connector X3 (see section 3.3.1). Using the Mint WorkBench Digital I/O tool, the
input can be configured to be the motor trip input. This allows the MicroFlex
e
100 to respond to
motor over-temperature conditions. The Mint keyword
MOTORTEMPERATUREINPUT
can also be
used to configure a digital input for this purpose. A typical circuit, using DIN1 as the input, is shown
in Figure 9.
A
B
motor
thermal
switch
Relay
Customer
supplied
24 VDC
supply
+24 V 0 V
Separate
customer
supplied
24 VDC supply
+24 V 0 V
DIN1+
DIN1-
16
6
‘X3’
The relay has normally open
contacts and is shown deactivated
(contacts open, motor overheated).
Figure 9 - Motor thermal switch circuit
The 24 VDC power supply connected to the thermal switch must be a separate
supply as shown in Figure 9. Do not use the 24 VDC supply used for the drive
enable signal, or the internally generated supply (if present). The thermal switch
wires often carry noise that could cause erratic drive operation or damage. The
thermal switch contacts must never be wired directly to a digital input or any part
of the logic supply for other components in the system.
The separate 24 VDC supply used for the thermal switch may also be used for the
motor brake circuit (section 3.5.6).
CAUTION