Greetings to all!

We use 2 x 6sl3320-1tg41-0aa0 in parallel. It operates an electric motor of 1300 kW. The p1800 parameter is set to 2.5 kHz, but during operation in r1801, 1.66 kHz is displayed. At that time, the motor module does not work with overload, as the description of the parameter p1800 says. Why then the pulse frequency is reduced? 

Sometimes, pulse frequency is reduced if the semiconductors becomes to hot.

You may check temperature and cooling system.

At this time, the temperature data look like this:

r37[0] 36

r37[1] 45

r37[2] -200

r37[3] 26 

What are the critical values affecting r1801 аnd where to find them?

... please check parameter p290

there is the reaction for overload (for example current limitation, or puls frequency change or doing nothing, ...)