Or mathematically:
Let…
S = safety factor
Ing = number of engineers involved in a drive design
then:
S is proportional to |Ing|
where…
|Ing| = cardinality of I (number of engineers)
What do I mean by that? 🙂
In fact, a safety factor is added every time a required performance is specified. The person who calculates it at the machine manufacturer, the person who requests it, the person who translates the request into a drive solution, the person who finally defines the drives – they all add a little bit of safety margin.
In the end, oversized drives are often requested and designed.
Solution: Provide the drive manufacturers with clear torque-speed characteristics over time – for your specific machine. If the drives meet these requirements, you can be sure of getting the optimum drive.
Or: Test the motors. But start with the smaller design! Why the smaller one? Because otherwise the status quo effect will kick in (just ask the internet/AI—going too far here 😅).
In fact, if you start with the more powerful solution, you usually can’t get away from it.
One final note:
In practice, it is of course highly relevant to determine the proportionality constant k correctly. So if S=k |Ing|.
k also depends heavily on the risk culture of the company. 1.1…1.2 is a good average, i.e., 10-20%. However, risk-averse engineers may use up to 1.5 (50% certainty).
Salespeople work according to a different law, by the way! That’s important to know. Here, k is more likely to be <1. 😅😎😉
👉 Feel free to follow me on LinkedIn for more practical knowledge on the subject of drive technology.