text: <s>[INST] SMC Flex Par 50 Are the thermistor inputs used to calculate the %MTU ? , and if so can Par 50 be adjusted to give a trip point ? [/INST] MTU is motor thermal usage and is a mathematical model that simulates the amount of heat generated in a motor due to current draw over time. It is based on an I^2T algorigthm (where I is current and T is time). Some of the factors used to calculation are what the full load current of the motor is set at, what the actual current draw of the motor is, and the amount of current used to start the motor. PTC value isn't used for that... it gives you an option to have an enhanced control of motor temperature. An alarm (pre-fault) indication level can be programmed to indicate the unit is getting close to faulting. The alarm modification information is displayed through the LCD, HIM, Communication (if applicable) and alarm contact closing. Parameter 50 is used to set an alarm status in the SMC-Flex based on the programmed level in it...If you want to be advised before %MTU reach 100% and the overload occurs, then you've to program a value at which you will have an alarm...default is 50%. Hope this helps...- fuzzy logic \\n </s>