WattMaster WCC II - Manual (Page 173)

Section 3: Screen Descriptions
WCC II Operator’s Guide
Operator Interfaces 3-141
As the space temperature drifts farther from setpoint, the TUC will
send a longer pulse ON-time to cause the pneumatically controlled
device to move faster.
Pulse ON-time in seconds
|---------------------------------------- |
+-----------------------------------------------------------------------------+
|///////////////////////////////////////////////// |
+-----------------------------------------------------------------------------+
15 times longer than the entered “pulse on-time”
|-------------------------------------------------------------------------------|
If the actual temperature is 3 °F or more from the deadband, the
TUC will send a continuous pulse signal to the pneumatically
controlled device to cause it to move at full speed.
Pulse ON-time in seconds
|-------------------------------------------------------------------------------|
+-----------------------------------------------------------------------------+
|////////////////////////////////////////////////////////////////////////////////////////////////|
+-----------------------------------------------------------------------------+
15 times longer than the entered “pulse on-time”
|-------------------------------------------------------------------------------|
Reversed action during MWU:
You can cause the TUC to reverse the control action during the
morning warm-up period by entering YES here. The morning
warm-up period is active whenever the “Reverse Action” input on
the EA Driver Screen is enabled.
For example, in the normal mode, the TUC will energize the “feed”
terminal if the space temperature is above setpoint and energize the
“bleed” terminal if the space temperature is below setpoint. In the
reverse action mode, the TUC will energize the “bleed” terminal
if the space temperature is above setpoint and energize the “feed”
terminal if the space temperature is below setpoint.
Forced bleed: [ON] [OFF] [No]
Forced fi ll: [ON] [OFF] [No]
You may manually override the “feed” or “bleed” terminal either
ON or OFF. The override will take effect when you leave the TUC
Setup Screen.
Use hysteresis on deadband: [YES] [NO]
Hysteresis is also called “switch differential” and is the amount
the space temperature has to change before the switch will change
state.
For example, assume we have a setpoint of 74 °F, and a hysteresis
of +/- 0.4 °F. When the space temperature rises to 74.4 °F, the
switch changes state, and when the space temperature falls to 73.6
°F, it switches back to its original position.