RK3000 High Frequency Power Supply
Operating Manual
Page 15 of 73
period of time from the last spark or arc occurrence. (For a more detailed description of
Process Sense, see Discussion of Typical Control Waveforms, page 52).
This control feature assures stable and rapid recovery after a process upset has
subsided.
Quench Mode
The Quench
Mode is programmable; it can activate the Quench time for “Arcs Only” or for
“Sparks and Arcs”.
With the Quench Mode set to Arcs Only, the detection of a second spark within the Arc
Delay time will cause the Quench Time feature to become active. This is the preferred
operating mode for precipitators collecting ash from the burning of coal.
With the Quench mode set to Sparks and Arcs, the detection of a spark will cause the
Quench time to become active (For a more detailed description of Quench Mode, see the
Discussion of Typical Control Waveforms, page 52.)
Quench Time
When a second spark occurs within the Arc Delay time it is considered an arc and it is
necessary to turn off the power for at least one system cycle to ensure the arc is
extinguished. Turning off power after this second spark is detected is called Quench.
The length of time a Quench occurs is the Quench Time, and its length is programmable
(see Preprogrammed Levels And Operating Ranges, Page 68).
Ramp Rate
The Ramp Rate is the rate at which the precipitator power increases after a Phase Back.
Power recovery starts from the Phase Back level and continues at the Ramp Rate until
either current limit or voltage limit is reached or a spark or arc occurs. The time
programmed for the Ramp Rate is the time it takes the power to increase from the Phase
Back level to pre-spark current level.
The Ramp Rate is field-programmed (see Preprogrammed Levels and Operating Ranges,
page 68) for the lowest opacity operation under normal operating conditions (For a more
detailed description, see Discussion of Typical Control Waveforms, page 52).
Rapping System Set-up
If onboard timers, and relays located on the Control Unit, are being used to operate
motors that drive mechanical rapping systems, this set-up allows the timing and anti-
coincidence parameters to be programmed.
Both the Interval and On-time of the motors as well as groupings for non-simultaneous
operation of the motors can be adjusted.
Re-initialize
Selecting this routine erases the contents of control memory and resets all parameters to
their default values. There are two different re-initialization routines, one for the Control
Unit and one for the Keypad and Display Unit. The control must be reprogrammed after a
re-initialization is requested.
Relay Timers
This control can be configured with up to four on-board relays with normally open
contacts. The on and off times of these relays are set through the keypad. These relays
can be used for controlling motor operated cleaning systems, electric vibrators, air
solenoids, and wet precipitator wash-down systems.
Conduction Display
The control can be programmed to display the IGBT firing percentage. How closely a
control is matched to the actual transformer load is judged by comparing the actual
