Key Benefits

  • Intuitive and user friendly
  • Easy troubleshooting
  • Flexible and simple to install and operate

PIACS DC controllers

Best ESP control strategies

FLSmidth’s PIACS DC4 control unit for Electrostatic Precipitators (ESP) provides plant operators enhanced utilization of installed power which in turn improves ESP efficiency and reduces dust emissions. Our
microprocessor-based PIACS controller incorporates the best ESP control strategies to avoid process fluctuations delivering superior ESP performance that helps you save energy. The PIACS DC4 control unit has evolved from 40+ years of experience in providing over 4,000 ESP installations worldwide.


Our PIACS controller uses a patented method to detect back corona and avoid process fluctuations. Our controller features an enhanced stability monitor for ESP and process optimization. We enable superior ESP performance with improved spark detection and a patented rapid voltage recovery system. Also, our controller helps you save energy using a built-in energy management control system (EMCS). 

User experience like never before

We designed the new PIACS DC4 with emphasis on an intuitive user interface so it is clear and simple for you. With distinct visual layers, clear text, symbols, and icons, we make it easy for you to navigate the system. We’ve built in rich content and functionality that you can seamlessly discover through smooth transitions without ever losing context.

Engineer working on PIACS DC4 ESP controller touch screen

Built-in ESP manager

Our built-in ESP manager eliminates the need for an external computer or special software. With the new PIACS DC4, it is now possible to access the ESP control interface through a built-in ethernet connection. This allows your plant maintenance staff and our specialists to service the equipment remotely all of which increases ESP reliability.

Engineer working on PIACS DC4 control manager software from laptop

Unique service facilities

Our PIACS DC4 controller offers several unique service functionalities that help you maintain the ESP high voltage (HV) system including a built-in help menu with troubleshooting tips. Service tasks are addressed using a 4-channel oscilloscope and the firmware is easily updated via a USB port. There is a self-diagnose tool for the panel and I/O controller, and, for testing purposes, manual controls of firing angle and ESP current.

With the PIACS DC4 controller you can also detect failures inside the ESP using a 4-channel trend log of all essential operating values plus an alarm log and a history log. You can access current voltage curves (CVC) in automatic or manual mode and customize the event log for specific parameters and configurations that are important for you. What’s more, you can easily export CVCs, trending data, events and scope data to an ftp server or USB memory card. Finally, your system configuration can be fully backed-up and restored with ease.

Engineer working on electrical panel

Custom-made systems or retrofitting existing control panels

Our PIACS DC4 is available for new ESPs, or you can easily upgrade your existing controller in a manner that fits your needs. We have successfully upgraded existing ESP control systems from all different manufacturers, starting with the first generation of PIACS controller.

A modern ESP control system that is user friendly, flexible, easy to use and maintain

Intuitive and user friendly
Our new PIACS DC4 has an intuitive user interface so it is clear and simple for you to navigate the system and access additional content and functionality without ever losing context. With several configuration options, you can customize the event log for specific parameters that are important for you and export key data, such as CVCs, trending, events and scope data to ftp or USB memory for additional analysis or reporting.
Flexible, simple to install and operate

Compared to previous generations of PIACS controllers that were built for each section of the ESP, we designed the PIACS DC4, with an expandable I/O system.  Our design offers an almost limitless modular system and fully customizable control panels that can be tailored to your needs, so you are no longer bound to only three rapping and heating feeders.

Additionally, with our PIACS DC4, almost all parts can be used in both single and three phase T/R systems. This means you save on spare parts, keep track of fewer parts, and only require one order number. Also, transitioning between single and three-phase T/R system is easy.
Easy troubleshooting
Our new PIACS DC4, with a Built-in ESP manager, offers access to the ESP control interface through a built-in ethernet connection removing the need for a computer or external device. Plant maintenance staff and FLSmidth experts can service the equipment remotely. Additionally, FLSmidth also offers various service packages, including 24/7 support via remote access from our Copenhagen central or our local customer service office.

Unique and powerful

features for superior user experience while securing low particulate matter emissions

The PIACS DC4 is highly user-friendly and enables the utilization of best ESP control strategies. Improved performance, energy savings, and operational stability can all be realized with this latest automatic control system for ESPs.


The key features for the PIACS DC4 controller include:

  • Improved ESP voltage and current measurements
  • Optimization of corona power delivered to the ESP bus section
  • Faster voltage recovery following sparks for improved performance
  • Robust controller construction for increased reliability of components
  • Automatic optimization, including patented method for back corona detection
  • Modular design with ability to expand by up to 90 rapping gears and 90 heaters and two purge-air units
  • Available for new ESPs and for retrofits.
  • Pre-cabled and pretested back panels can be delivered and installed in the existing cubicles with expert support to ensure new control systems are properly installed in existing ESP control panels
  • Built-in retrofits can be performed during maintenance outages or during operation, field by field
  • Delivery of retrofit kit parts with all required components for upgrading an existing panel with one-phase or three-phase thyristor control.
  • Cost-efficient spare part strategy - Common parts for single and three phase systems
  • Built in ESP Manager with remote monitoring and 24/7 support



Component Specification
ECP Touch Panel

- 15,6” touch panel capacitive touch screen

- Common controller for one chamber

- Modular system supporting - Built-in ESP manager for remote support

-  High-speed data communication with slave nodes using Ethernet Powerlink.

FB – Firing Board

- Single-phase firing board (3 phase systems use three single-phase units)  

- Mains voltage up to 690V, 50/60Hz - No active power supply for driver circuits

- One fibre optical firing for both half-cycles of the line frequency

- Status fibre for line synchronisation and status of firing

iCU – intelligent Control Unit

- iCU supports both single and 3-phase systems

- Power controller for firing board up to 690V - 50/60Hz

-  Fiber optical firing of the SCR unit(s) - electrical separation between iCU and firing board

rMU – remote Measuring Unit

-  High voltage control & alarms

-  For unit status and maintenance (7-segment LED for status indication or manual control of firing angle/current control).

- Service interface via serial USB

-  Analog monitoring of SCR units and control cabinet temperature


Notice and brochure

PDF (4064KB)

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