life cover / 1.14 Public besign

The design of this kind of sewer cover mainly consists of the “led” warning light and sense switch. And it is surpported mainly by reserved and source current.
The switch will be touch off and then the “LED” lights up when the cover is off the warning ring. So the passersby and cars can get the notice to get away from this risk area.
In general, the warning ring is closed when the cover rightly shield the sewer .When the cover is lifted and the switch is touch off , the cover ring will issue a red warning light while the wireless signal will be sent to involved parties to tell them that there is a problem with the cover.