Transformer-Rectifier Accessories

Current Limiting Reactors

Current Limiting Reactors (CLRs) protect both the TR set and the Silicon Controlled Rectifier (SCR) Controls. Hamon Research-Cottrell stocks several sizes of CLRs for either internal or external mounting. Hamon Research-Cottrell also stocks many replacement TR components.

Diode Stacks

Diodes, also commonly called rectifiers, are used to provide one-way electrical current flow in an electrical circuit. The rectifier in the precipitator TR set is made up of many small, low voltage diodes connected in series. This creates a rectifier capable of operating at the high voltage potentials that are present across the rectifier "stack". Two identical stacks are used in a TR set, one connected to each A.C. side of the transformer output at the rectifier center junction. This provides for rectification of each side of the A.C. sine wave. The two positive ends of the rectifier are joined together and connect to the precipitator "ground" through a resistor (control signal feedback) circuit to provide the positive voltage to the collecting electrodes. The negative ends are commonly connected together to create the negative voltage to the discharge electrode system. In some applications, the negative end remains separated and is fed through separate high voltage insulators to 2 different discharge electrode grids. This is known as "half-wave" energization, as it takes the rectified negative pulses of the A.C. sine wave and sends one pulse to one discharge electrode grid, then 180 degrees later sends the other pulse to the other discharge electrode gris. Hamon Research-Cottrell stocks diode stacks for many common sized TR sets.

Transformer-Rectifier High Voltage Bushing Insulator