What is the difference in RCDs of different types and what are they?

Good afternoon, are you definitely not mistaken? Neither I nor even Google knows. DM and DE - this is found in the names of models of individual manufacturers. But RCDs are of different types according to the leakage current, for example, RCDs type A - for direct (pulsing) and alternating current, AC - for alternating leakage current and type B - for alternating, direct or rectified leakage current. There are also S type RCDs - selective, i.e. they fire with a time delay of 0.15-0.5 seconds, and type G is also selective, but with a longer shutter speed - 0.6-0.8 seconds.

There are other types, for example AP-R, type F, but they are modifications of the above types, for example, F is almost like type A, only taking into account different frequencies of leakage currents for consumers with a frequency converter (such as modern household appliances with an inverter drive ) or AP-R with delayed response is slightly less than selective.

Another classification according to the power source is electromechanical, which does not require the presence of phase and zero, i.e. independent of the power source and electronic - which are dependent on the power source (read how - it will not work when the zero burns out).

Unfortunately, I do not know about other gradations (or I just forgot).