VG Overspeed Governor
The VG Overspeed Governor (VG OSG) is designed to be installed in new lifts and retro fitted to existing passenger and goods lifts and when used in conjunction with other VG Safety products such as the VG Safety Gear and or the VG Rope Brake will provide a complete solution to the requirements of EN81-1:1998+A3: 2009. It can also be used with other “CE” marked safety products,but the responsibility lies with the lift designer to ensure correct operation in these circumstances.
The VG OSG connects to the main lift control panel via its own specific controlbox (VG OSG – CB01). From here it can receive power and signals to tell if the lift doors are open, the state of the main motor contactor and the condition of the main safety circuit. It also sends signals to the lift, warning the lift controller if the lift speed reaches 110% above the normal running speed (Alert Signal) and will operate the “CE” marked braking means in the event of overspeed or unintended car movement.
The system will always deploy immediately and interrupt the main lift safety circuit if:
- Overspeed is signalled
- Unintended car movement away from the landing with the landing door not in the locked position and the car door not in the closed position
- If the emergency stop button on the front of the control panel (VGOSG-CB01) is pressed
The governor incorporates a bi-directional drop-jaw mechanism which is monitored by state of the art electronic sensors and operates by releasing a12V dc electro-magnet in the event that either overspeed or unintended car movement is detected, or the emergency stop button pressed.
When either overspeed or excessive unintended movement is detected the governor will be activated which in turn will deploy the brakes under its control and in addition to this an emergency stop signal will be sent to the main lift control panel, by means of interrupting the main saftey circuit.