Operation diagram
≥ 3800 Ω
A1/A2
≤ 1500 Ω
≤ 20 Ω
P1/P2
R [Ω]
X1/X2
Test/Reset
11-14/21-24
11-12/21-22
1 2 3 4 5
Tests1
Overtemperature/broken wire detection2
Voltage failure/reset3
Sensor short-circuit4
Test/Reset5
Wiring
■ Insulation of the sensor circuit
When you connect the temperature sensor(s) of the Ex motor to the drive STO terminals
through a relay, make sure that there is reinforced (double) insulation between the main
circuit (motor) and the drive control unit as required by IEC 61800-5-1. The insulation of the
temperature sensor in the Ex motor and the insulation of the protection relay form the
insulation of the whole circuit. All Ex motors manufactured by ABB have basic insulation
between the main circuit and the temperature sensor. The thermistor relays shown in this
manual have basic insulation between the sensor circuit and relay output. This ensures that
there is double insulation between the main circuit and the drive control unit.
24 ATEX-certified motor thermal protection function with PTC thermistor relays (+L513+Q971)