WattMaster WCC II - Manual (Page 172)

Section 3: Screen Descriptions
WCC II Operator’s Guide
Operator Interfaces 3-140
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The TUC-P and TUC-PR models have the capability of driving
two 24 VDC solenoid air valves to obtain “feed” and “bleed”
type control of pneumatic powered devices. If the TUC has the
pneumatic driver circuit, this menu will automatically appear as
part of the TUC Setup Screen.
Use [low] [high] resolution on deadband
The deadband range is either +/- (0-15) °F or +/- (0-3) °F depending
on which range is selected.
Low resolution = 0-15 °F Deadband Range
High resolution = 0-3 °F Deadband Range
Deadband is [0-15] Deg F and pulse on-time is
[1-255]/10 seconds [0-3]
The deadband is user entered and can range from 0-15 °F entered
as whole numbers or 0-3 entered in 0.2 °F increments depending
on which resolution is selected. The deadband is the range above
and below setpoint that the pneumatic driver does not energize the
“feed” or the “bleed” solenoid air valve. That is to say, when the
temperature is within the deadband, the controlled device remains
in its present position. The value entered here is a +/- value from
setpoint.
For example, if the setpoint is 72 °F, and the deadband is 2 °F, the
deadband is from 70 °F to 74 °F.
The “pulse on-time” is active when the proportional mode is used.
The “/10” means that the number entered as the pulse on-time
is divided by 10. For example, if you want a pulse on-time of 2
seconds, 20 is entered.
Use Proportional Mode [Yes] [No]
If you choose to use the proportional mode, the TUC will pulse the
“feed” and “bleed” solenoid air valves to cause the pneumatically
controlled device to move faster as the actual temperature moves
farther from setpoint. If you do not use the proportional mode, the
TUC will continuously open either the “feed” or “bleed” solenoid
air valve as the space temperature drifts out of the deadband.
Proportional mode
When the actual temperature is just outside of the deadband, the
TUC will pulse either the “feed” or “bleed” solenoid air valve to
move the controlled device and bring the temperature back into the
desired range. When the actual temperature is just barely out of the
deadband, the TUC will send a pulse and then wait for a time period
of 15 times longer than the pulse. As the space temperature gets
farther away from setpoint, the TUC will cause the pneumatically
controlled device to move faster. When the space temperature is
3 °F above or below the deadband, the TUC will continuously hold
the “feed” or “bleed” solenoid air valve open to drive the device
at full speed.
When the actual space temperature is just outside of the deadband,
the TUC will pulse the “feed” or “bleed” air valve for the pulse on-
time entered on this screen.
Pulse ON-time in seconds
|--------|
+-----------------------------------------------------------------------------+
|//////////|
+-----------------------------------------------------------------------------+
15 times longer than the entered “pulse on-time”
|-------------------------------------------------------------------------------|
PNEUMATIC OUTPUT SCREEN
-----------------------------------------------------------------------------------------
------------------------Pneumatic Output---------------------------
Pneumatic Mode: [Pneumatic Driver] Use [low] resolution on deadband
[high]
Deadband is [0-15] Deg F and pulse on-time is [1-255]/10 seconds
[0-3]
Use proportional mode: [Yes] Reverse action during MWU: [Yes]
[No] [No]
Forced Bleed: [ON] [OFF] [No] Forced Fill: [ON] [OFF] [No]
Use hysteresis on deadband: [Yes] [No]
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