RK3000 High Frequency Power Supply
Operating Manual
Page 14 of 73
External Alarm Message Text
In conjunction with the external alarm inputs, there are preprogrammed tags
(descriptions) that can be assigned to each input. .
Max Set Size
The same microprocessor control components are used regardless of the size of the TR
they are connected to. In order for the control to know what size TR it is connected to,
the TR name plate ratings are field programmed into the control in a programming screen
called Max Set Size.
Pedestal Rate
This feature operates in conjunction with Quench (see quench definition on page 15).
After each Quench, the rate at which the power is reapplied to the precipitator is the
Pedestal Rate. The Pedestal Rate is a programmable parameter (see Preprogrammed
Levels And Operating Ranges, page 68). The rate is the number of cycles to recover
from zero to the equivalent Phase Back level had the arc been a spark. (For a more
detailed description of Pedestal Rate see the Discussion of Typical Control Waveforms on
page 52).
Phase Back
Phase Back is the amount of power reduction that takes place after each spark
occurrence. The amount of Phase Back is programmable (see Preprogrammed Levels
And Operating Ranges, page 68).
Since it is undesirable to operate at high sparking levels, the Phase Back reduces power
in an effort to keep the operating power just below the threshold of sparking. Typically,
fewer sparks result in more uniform power in the precipitator and more stable precipitator
efficiency. (For a more detailed description of Phase Back, see Discussion of Typical
Control Waveforms, page 52).
Power Down Rapping
If the TR controller is communicating with a Microprocessor Rapper Control (MRC-NT)
over a communications loop, or the optional relays and timers are installed on the Control
Unit for controlling motor drives of mechanical rappers, the TR power level can be set for
a value below the automatic level when rappers are energized. Lower power levels make
it easier for the particulate to be released from its collecting surface.
Pre-Spark Readings
The display shows the last set of electrical readings that were taken prior to a spark. It is
used for diagnostic purposes when trying to determine the kV spark over level.
Primary Current Limit
The Primary Current Limit is typically programmed for the nameplate current rating of the
transformer-rectifier being controlled. The Primary Current Limit prevents the
transformer-rectifier primary current from exceeding the programmed value. This limit
can be used to limit operation of the control below the transformer rated current, if
desired.
Primary Voltage Limit
The Primary Voltage Limit is typically programmed for the nameplate current rating of the
transformer-rectifier being controlled. The Primary Voltage Limit prevents the
transformer-rectifier primary current from exceeding the programmed value. This limit
can be used to limit operation of the control below the transformer rate primary voltage, if
desired.
Process Sense
The Process Sense function monitors the time between sparks and arcs. It automatically
overrides the Ramp function if a spark or arc does not occur within a programmable
