NWL’s Graphic Voltage Controller (GVC) is a powerful tool for clean-air management and compliance, offering precise monitoring and control for NWL's ESP Transformer/Rectifier (T/R) sets and power supplies.  GVC is available as a complete system, including:

• All SCR (Silicon Controller Rectifier) components
• Hardware for incoming power (Contactor and Circuit Breaker)
• Analog meters for VAC/AAC (primary voltage/current) and kVDC/mADC (secondary voltage/current)
• NEMA rated enclosures for a variety of ambient conditions
• Control Electronics System
  • Control Module - (CPU, I/O board and power supply)
  • Trigger Module - takes low voltage pulse from CPU to SCR
  • Hand Held Module - LED display that can monitor and control up to 90 T/R sets

Control Electronics Module

In July 2010, we introduced our new module, which is based on new Texas Instruments Digital Signal Processor (DSP) technology. 

Communication Options

• The GVC is easily integrated into our Precipitator Control and Management System (PCAMS).  PCAMS is NWL's central precipitator control system with the capacity of up to 8 precipitators, and 90 T/R sets per precipitator.  With the optional OPC server, PCAMS can deliver all precipitator data directly to your DCS.
• NWL's Distributed Control Systems Interface (DCSi) is a simple and inexpensive way to link your GVCs to your plant's DCS.  This interface module can accomodate up to 24 GVCs.
• Our GVC can be configured to communicate to your DCS using Modbus RTU protocol via a RS 485 network port.   The port runs at 9000 baud and can be daisy chained per the RS 485 Standard.

Control Upgrades Available!

Many companies have upgraded their old analog controls with just our GVC control Module.  The entire package costs less than $2000, so it can be purchased under most companies' R & M (repair and maintenance) budget.  Installation can either be performed by a qualified electrician or an NWL Field Service Technician.  For more information about this upgrade, please email us.   

The GVC uses a detachable and hand-held keypad input and display module for convenient technician interface. A single unit can access up to 90 transformer-rectifier controllers through a few simple keystrokes.

The GVC readout features a dot-matrix display and tactile, push-button switches mounted in a small, rugged all-environment assembly. The unit can be handheld or panel-mounted and has a life expectancy of 30 years under normal use.

Key features include:

• Comprehensive voltage control and visual monitoring of ESP power supplies
• Can communicate to any plant  DCS system with most data protocols
• Numerous upgrade packages available 
• 640 character LED display
• Software for calculating V/I curves, bar graphs and trending
• Sophisticated arc detection system
• Provides for back corona detection
• Local or remote control options
• Can be integrated into NWL’s PCAMS

For more information, please see our new GVC brochure. 

To specify a controller package, please fill out this configurator form and email it to us.

GVC user manuals can be found here.

List of latest software revisions