Symmetrical distribution of the control devices across all phases is advantageous. Please observe the installation instructions from the control device manufacturer. The switch operates independently of its position. Therefore, the protective switch can be used in accordance with the installation regulations for fault protection and additional protection. The 4-pole switch can also be used as a 2- or 3-pole switch. See connection examples. The test button "T" must be pressed every year. The operator of the system must be informed of this requirement and its responsibility in writing. In special conditions (construction sites, laboratories), the test button may need to be pressed more frequently. The statements of the respective installation regulations apply here. Pressing the test button "T" only tests the function of the residual current (FI) protective switch. This test does not replace the grounding resistance measurement (RE) or the proper protective conductor condition check, which must be conducted separately. Type B: Short-time delayed and surge-resistant 3 kA, all-current sensitive, Type B (ÖVE E 8601). Type B: High reliability against false tripping. Mandatorily required for circuits with potential personal or property damage in the event of false tripping (ÖVE/ÖNORM E 8001-1 § 12.1.6). Type S/B: Selective and surge-resistant 5 kA, all-current sensitive, Type S/B. Type S/B: Selective residual current protective switch. Protects against all types of residual current forms.