The Siemens 3RB1900-0A is a sealable cap that fits over the current-setting knob and class-selector on 3RB series overload relays. It prevents unauthorized adjustment after commissioning — a common requirement on production lines where settings must remain locked.
Fit & Integration
Designed specifically for the 3RB overload relay family. The cap snaps onto the front of the relay, covering both the current-setting knob and the class-selector switch. Once sealed, it deters tampering without removing the relay from the panel.