Will a UPS failure cause the device to stop operating?

1. Your understanding is correct. The main control room of petrochemical plants typically uses mains electricity, while the UPS (Uninterruptible Power Supply) serves to continue supplying power to the DCS system in the event of a power outage or malfunction, ensuring that the system remains operational and preventing data loss as well as sudden shutdowns of the equipment. 2. If the mains power is normal but the UPS fails (and there is only one UPS), the computers in the control room may go black due to the lack of backup power. In this case, if the computer is in charge of critical operations, it may affect the operation of the DCS, which could in turn lead to the shutdown of the equipment inside the unit. Therefore, the importance of timely maintenance and inspection of the UPS system cannot be ignored. .

A UPS is essentially a backup power source that provides power in emergency situations over a certain period of time. UPS power supply is designed for emergency operations that involve stopping the production process of equipment and devices promptly, so as to bring them into a safe, stationary state as early as possible. As for the power supply source, in large chemical enterprises, it is provided directly through dedicated lines. For some large-scale equipment, starting it requires contacting the power supply provider to coordinate the load before it can be operated. Generally, grid failures are rare; most power outages are caused by improper electricity use within enterprises. For reference.

You can think of the function of a UPS in this way: your DCS system is like the laptop’s main unit, while the UPS is equivalent to the battery in that laptop. There is a charger taken from a wall socket connected to the laptop’s charging port. When the outlet runs out of power, the laptop’s battery supplies power to the host, and this is the function of a UPS as a backup. Of course, in reality, as mentioned above, the UPS uses mains power to supply the DCS system. However, it’s not raw mains power; rather, it’s mains power that has been processed. The mains power enters the UPS, where it is first rectified into direct current. This DC power then splits into two paths: one path supplies the UPS batteries, keeping them in a fully charged state; the other path goes to the inverter, which converts the DC power back into mains power for use by the DCS loads. Therefore, the inverter in a UPS is very important. If a malfunction in the UPS affects the inverter, it means that the DC power from the backup batteries (as well as the DC power obtained after rectifying the mains power) cannot be converted by the inverter into AC power to supply the DCS loads. As a result, the DCS screen will go black. Therefore, UPS systems typically come equipped with a bypass function, which allows the mains power to be fed directly to the DCS loads, bypassing the UPS. All of these functions need to be tested and verified to ensure their reliability during maintenance work

In petrochemical plants, the DCS in the main control room is generally powered by a dual-circuit system, with power mainly coming from on-site generators; if these generators are under maintenance or fail, the system relies on external power supplies. As for UPS, it is merely a backup power source for use in emergency situations over a certain period of time.

The power supply for the DCS control section comes from two separate circuits; it is generally supplied by one set of UPS units, one mains power source, or two UPS units. The UPS units keep supplying power continuously, and when the main power supply fails, they automatically switch to the batteries as a backup. The UPS units are not used only as a backup power source in emergency situations. Additionally, the lighting and fans in the DCS cabinet are powered by another mains power source

No, the UPS is connected in parallel with the mains power