Spencer Electronic Modulating Bleed Control - Manual (Page 2)

The Spencer Turbine Company 600 Day Hill Road Windsor, CT 06095-4706 TEL 800-232-4321 ◆ 860-688-8361 ◆ FAX 860-688-0098
I. Overview
The Electronic Modulating Bleed Control (EMBC) will monitor
the current load of a blower or vacuum producer and open a
bleed valve to prevent the machine from operating in a surge
condition. It will also close the bleed valve when there is suffi-
cient system load for normal operation. The lower portion of the
panel is divided into three categories: Display, Function, and
Program. The Display group is linked to the 4-digit digital
display (11), indicating the "units" of the numerical value
being displayed, either Amps or SCFM. The Function group
acts as a status indicator for valve positioning control. Finally,
the Program group contains push buttons that allow the user to
interface with the controller.
The EMBC is programmed at Spencer with machine-specific
data, allowing for more precise control in a machine and con-
troller "matched set" configuration. The Amps/SCFM ratio will
therefore be tailored to the blower or vacuum producer perfor-
mance as determined by factory testing.
II. Applying Power
When power is applied to the EMBC, an initialization sequence
takes place. The controller’s 4-digit display will indicate: 8.8.8.8.
followed by 0000, 1111, 2222, 3333, ........ 9999, SPENCER
EnBC. When the initialization sequence is complete, the Amps
LED (Light Emitting Diode) (3) will light to indicate that the digital
display is in the amps mode. The Valve Closing LED (5) will also
illuminate, indicating that the valve is being closed. The Valve
Closing LED will remain lit for 15 seconds and the controller valve
close output relay will remain energized for 15 seconds to allow
the valve actuator to fully close the bleed valve. Note: The bleed
valve should be fully closed before starting the blower/
vacuum producer.
When the initialization sequence has been completed, pressing
the "start" push button on the control panel will start the blower or
vacuum producer. As the motor gains speed, the motor current
can be seen on the 4-digit digital display (11). By pressing the
Display button "D" (9), the digital display may be changed from
"Amps" to "SCFM" and vice versa.
III. Set Points
The EMBC Universal Controller has two fully programmable set
points. These set points are for Bleed Valve open (minimum
flow prior to surge) and Bleed Valve close (minimum flow to
close the bleed valve without causing the valve to immediately
reopen). If the machine is operating in the region between the
two set points, the valve will idle in a partially open state until
the load changes, prompting the valve to open for additional
load or to close to avoid unnecessary load on the motor.
Valve Open (avoid surge):
The valve opening set point can be adjusted by pressing the
upper Set button (12). The Valve Opening LED (2) will illuminate
and the digital display (11) will show the Valve Open set point in
amps with the tenths digit flashing. To change the tenths digit in
the set point, press the Up button (10) or the Down button (7). To
change to the units digit, press the Display button "D" (9) and
the units digit will flash. Now press the Up button (10) or the
Down button (7). Pressing the "D" button (9) shifts the numerical
place value to the left, allowing for a quicker change. To save the
new set point and return to the Amps Display (normal operation),
press the Reset/Enter key "R/E" button (8). This key must be
pressed to exit the "Set" mode.
Valve Close (avoid unnecessary system output):
The valve closing set point can be adjusted by pressing the
lower Set button (6). The Valve Closing LED (5) will illuminate
and the digital display (11) will show the Valve Close set point
in amps with the tenths digit flashing. To change the tenths
digit in the set point, press the Up button (10) or the Down
button (7). To change to the units digit, press the Display button
"D" (9) and the units digit will flash. Now press the Up button
(10) or the Down button (7). Pressing the "D" button (9) shifts
the numerical place value to the left, allowing for a quicker
change. To save the new set point and return to the Amps
Display (normal operation), press the Reset/Enter "R/E" button
(8). This key must be pressed to exit the "Set" mode.
Note: If either "Set" button is pressed and no further operator
intervention occurs for 30 seconds, the controller will switch
back to normal operation. (The controller will revert to the
last operating display: Amps or SCFM.)
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11
Electronic
Modulating
Bleed Control
DISPLAY
AMPS
SCFM
FUNCTION
VALVE
OPENING
VALVE
CLOSING
PROGRAM
SET D
SET R/E
▲
▼
12
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2
3
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8
9
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11
1. Keypad Identifier
2. Valve Opening LED
(OFF = @ Rest, ON = Valve Opening)
3. Amps Display LED (ON = AMPS)
4. SCFM Display LED (ON = SCFM)
5. Valve Closing LED
(OFF = @ Rest, ON = Valve Closing)
6. Valve Closing “Set” Button
7. “Scroll Down” Button
8. Reset/Enter Set Points
9. Alternate Display Button
10. “Scroll Up” Button
11. 4-Digit Digital Display (7 Segment LED)
12. Valve Opening “Set” Button