Baldor MN1274 06/2001 installation manual Thermal switch connection, Motor thermal switch circuit

Pin 12 (CREF) controls the sense of all the digital inputs (X13 pins 1 to 9) and should be permanently wired, dependent on the user requirements, as described below:

Active high: connect +24VDC to pin1 and 0V to pin 12.

The digital inputs will be active when a voltage of +24VDC (±20%) is applied to them and will sink a maximum of 20mA.

Active low: connect +24VDC to pin12 and 0V to pin 1.

The digital inputs will be active when grounded and will source a maximum of 20mA.

The +24VDC supply mentioned above is from an externally generated 24VDC supply which should have a current capability of at least 3A to fulfill all the current requirements of the above loads.

The sense of the inputs can also be controlled individually in Mint using the keyword INPUTACTIVELEVEL. See also section 2.6 on page 26.

3.3.1.1Thermal switch connection

It is recommended to wire the motor’s thermal switch, via a relay, to an input on connector X13. Using suitable code, this provides a way for the Mint program to respond to motor overtemperature conditions. A typical circuit, using DIN11 as the input, is shown below.

B

A

Motor

thermal switch connections

Relay

+24VDC 0V

External 24VDC supply

X13
1
2	DIN10 (IN.10)
3	DIN11 (IN.11)
4	DIN12 (IN.12)
5	DIN13 (IN.13)
6	DIN14 (IN.14)
7	DIN15 (IN.15)
8	DIN16 (IN.16)
9	DIN17 (IN.17)
12	CREF

Figure 16 - Motor thermal switch circuit

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