Issues about "on-site and remote control" in DCS
Thread Content
Recently, I encountered a problem at work, which is a motor on site. The control button has a "onsite, remote control" selector switch button. But if I want to control it in DCS, how do I connect the power distribution panel to the DCS cabinet? Please know, express your opinion and learn from * middle.
The control buttons mentioned by LZ are equipped with "on-site, remote control" selection switch buttons, which refers to on-site manual automatic conversion switches. For example, for motor start and stop control, you can choose manual automatic. The on-site control loop is implemented by an electrical low-voltage switch cabinet. When DCS is required to implement it, it is necessary to lead two wires from the electrical low-voltage switch cabinet to the relay of the DCS control cabinet to achieve this control method.
There is a DCS contact signal contact on the secondary line in the power distribution panel, which has the same meaning as the start and stop of the manual button.
Lead two wires from an output contact of the output relay of the DCS control cabinet to the reserved remote control contact terminal of the local electrical control cabinet. When the switch of the local control cabinet selects remote, the DCS output contact is closed. Start the corresponding equipment.
This is how I handle the two-place control requirements that require DCS remote control and on-site control.: The starting priority of the motor is DCS--on-site. The stopping priority of the motor is on-site--DCS. This is relatively easy to implement and can meet many actual production requirements.
Considering the operation safety and production safety of the motor, the motor is divided into two control methods: remote DCS and local operation box. The main purpose is to ensure that the motor is still controllable if there is a problem with the DCS, and it is best to have an intermediate emergency stop position. Regardless of the driving method, when danger occurs on site, an emergency stop can be made on site to prevent accidents.