Wiring - Logic Outputs

Overview

The four logic outputs of the LTMR controller are relay outputs. The relay outputs command the motor managed by the LTMR controller.

The four relay outputs on the LTMR controller are:

Three single pole / single throw (SPST, NO) relay outputs
One double pole / single throw (DPST, NC+NO) relay output

Output Interposing Relays

When an output commands a contactor, an interposing relay may be required depending of the coil voltage and the power required by the contactor used.

The following diagrams illustrate system wiring without and with the use of an interposing relay KA1:

B1, B2 Power supply dedicated to logic outputs

The LTMR controller logic output characteristics are:

Rated insulation voltage: 300 V
AC rated thermal load: 250 Vac / 5 A
DC rated thermal load: 30 Vdc / 5 A
AC 15 rating: 480 VA, 500,000 operations, Ie max = 2 A
DC 13 rating: 30 W, 500,000 operations, Ie max = 1.25 A

If the LTMR controller logic output is not able to control directly the contactor, an interposing relay is required.

The protection module is mandatory on the interposing relays in order to suppress the surge.

Recommended Contactors

The tables in the appendix, listing the references and characteristics of Schneider Electric contactors, specify whether an interposing relay is required or not. Refer to the Recommended Contactors in the TeSys T LTMR Motor Management Controller User Guide.