摘要 |
A method for modernizing a hydraulic elevator including an elevator car guided by car guide rails for moving in an essentially vertical direction in the elevator hoistway, a hydraulic system including a lifting cylinder having a cylinder part essentially vertically supported on the base of the elevator hoistway and a piston rod moving in relation to the cylinder part and a hydraulic powerpack and a control center. The hydraulic system of the hydraulic elevator is modernized to include a function for preventing unintended starting at a floor, in such a way that the hydraulic powerpack is retained and an electrically-operating valve that is monitored with a control and that acts on the flow of hydraulic fluid of the lifting cylinder is added to the hydraulic system. The control controls a valve to prevent movement of the piston rod of the lifting cylinder downwards and/or upwards, if predetermined criteria are fulfilled. |