Boiler house
Local regulations may restrict the use of this product to below the conditions quoted.
TDS blowdown controls
In the interests of development and improvement of the product, we reserve the right to change the specification without notice. © Copyright 2017
TI-P403-90
AB Issue 6
BC3250
Blowdown Controller
Description
The BC3250 is a blowdown controller for steam boilers. It controls
TDS (total dissolved solids - salts in solution) by opening and
closing a blowdown valve.
It also has a timer that controls a bottom blowdown valve, to
remove precipitated solids from the bottom of the boiler.
The product works in conjunction with a Spirax Sarco conductivity
sensor, a boiler blowdown valve and, for condensate
contamination detection, a dump valve.
It can operate on a supply voltage of between 110 to 240 Vac at
50/60 Hz.
The front panel has an LCD graphics display and five-button
keypad to select, view, and change functions.
In run mode (standard setting) the display is divided into three
sections:
i) Process variable and control parameters.
ii) Information line, displays the various control states and
process units.
iii) Three bar graphs, which show a percentage of full scale of:
-
PV Process Variable highest and lowest recorded value.
-
SP Set Point and hysteresis point.
-
AL High Alarm and hysteresis point.
An additional filter can be selected to increase the damping effect
where the probe is fitted directly in the boiler. This avoids over-
frequent valve operation.
A Trend graph screen display appears if the right or left button is
pressed in run mode - This displays a record of the variation in
TDS over a set time.
The BC3250 can be used on a condensate contamination system.
Please note that it will not detect contaminants that do not change
the conductivity, e.g. oils, fats, or sugars.
The blowdown may be set to pulsed, rather than continuous
output, opening for 10 seconds, and closing for 20 seconds. This
avoids the risk of triggering a low water alarm in smaller boilers.
An isolated 0 - 20 or 4 - 20 mA output is provided for remote
display of the TDS level or as an output to a management system.
If a switch box is fitted to the bottom blowdown valve actuator,
an alarm can be configured to indicate if the bottom blowdown
valve fails to close or to lift off its seat.
The BC3250 can communicate via an infrared link between
adjacent controllers. It can be designated as either a master unit
or a slave unit.
The unit can be panel, DIN rail or chassis mounted.
BC3250
100
50
0
%
OK
Clamping screw
Graphic display
5 button display
Clamping screw
SP
PV
AL
Principal features:
-
Blowdown controller with bottom blowdown timer.
-
Multi-voltage 110 Vac to 240 Vac.
-
UL and TÜV approved.
-
Display in μS / cm or ppm.
-
LCD graphics display of PV and sequential trend graph.
-
Filter for turbulent conditions.
-
Infrared communications.
-
Diagnostic / test facility.
-
0/4 - 20 mA output.
-
EIA 485 / Modbus communications.
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