Microprocessor Transformer-Rectifier Control (MTC)
A backfit package includes the interface panel, microprocessor module, signal conditioning board, a CT (for primary current), a PT (for primary voltage), and an interface cable.
Effective energization of a precipitator is essential if the removal efficiencies required today are to be achieved. Precipitator professionals developed the Hamon Research-Cottrell transformer-rectifier controls with experience on virtually every application and set of operating conditions. As you would expect, the performance of the controls are essential for optimum precipitator performance.
MTC-G3 backfit packages can be installed in existing control cabinets in a few hours. When put into service the numerous features will enable the unit to deliver exceptional performance.
These features include:
- Patented arc detection circuit. The MTC-G3 uses the phase relationship between current and voltage to detect true arcs.
- Proportional spark rate control automatically selects the optimum spark rate. The controller reacts to each spark as dictated by the selected phase ramp and ramp rate parameters. Once these parameters are optimized, the spark rate will automatically adjust based on changing operating conditions.
- Dual back corona operating modes. When back corona is detected, one mode reduces the operating power amplitude while the other activates intermittent energization (IE). Being able to select the best site-specific mode insures top performance.
Peak secondary voltage and current limit protection during IE mode. The built in peak secondary voltage and peak secondary current limit parameters clamp these inrushes that normally occur when power is reapplied following IE "offtime".
The MTC-G3 keypad and display module can show more than 40 operating and alarm messages. Operators are kept aware of the control's normal operation, alarm conditions and activated operating modes. The display continuously shows:
- Transformer primary voltage
- Transformer primary current
- Instantaneous power
- Precipitator secondary voltages
- Precipitator secondary current
- Alarm/status
- Spark occurrence
- Spark rate
- Arc occurrence
- Arc rate
- Messages
- Electrical limit status
- Selectable display of SCR firing angle
The MTC-G3 proportional spark rate control automatically adjusts programmable parameters such as Phase Back, Ramp, and Pedestal to optimize usable power levels based on actual precipitator operating conditions.
Only one keypad and display unit is necessary to operate up to 32 TR controls. The MRC rapper keypad and display module can be located next to the MTC-G3 for simplified operation.
Hamon Research-Cottrell can supply the controls in complete cabinets complete with breakers, contactors, SCRs and analog gauges (if requested). Hamon Research-Cottrell stocks these components as replacement parts as well as voltage dividers and other accessories to completely upgrade your control system.
Replacement SCR modules with integral heat sink save installation time and provide a grounded system or added safety.
Voltage dividers enable older systems to have secondary voltage and current information required by Title V.
The Hamon Research-Cottrell DAVC Plus TR controller offers many of the features of the MTC-G3 but at a lower cost. The DAV-Plus conversion kit includes the control board, front panel controller with LCD display and key pad, mounting panel, relay and mounting socket and all components such as resisters, terminal block, ground bar and cable for a complete conversion.
Spark Response
An adjustable high-low energy spark discriminator allows selection of the threshold at which the spark response is initiated and the mode of response for the type of spark detected.
Adjustability of all spark response parameters during setup allows the full potential of control optimization to be realized.
These parameters include:
- Low energy spark power decrement and recovery ramp
- High energy spark off-time
- Fast ramp and conduction angle start, slope and endpoint
- Two stage slow ramp to sparking threshold
- Targeted spark rate
Back Corona Detection and Control
A schedule of voltage-current characteristic curves can be set up for Back Corona detection. Once Back Corona is detected, one of three responses can be selected by the operator - No Action, Power Savings Energization, or limitation of secondary current below onset of Back Corona.
Other features include:
- Self diagnostic software with LED indication
- Diagnostic routines executed during each power-up
- Password protection
- Adjustable limits on both primary and secondary voltage and current