In the US, I use the orange splitter HKJ suggested, along with a Fluke 375 FC for 2% accuracy +/- 5 digits, Since you requested “safely” in your question, it is by far the safest way to do the measurement, not to mention the ability to log and monitor with Fluke Connect remotely for utmost safety. With the flexible loop, it can handle up to 2500A, it is higher than anything I would want to get close to.