724-746-5500 | blackbox.com
Page 42
724-746-5500 | blackbox.com
Chapter 4: E2 Controller
NOTE: You may turn the A/C unit on and off at any time by pressing and holding the Enter key for 3 seconds.
Other status messages that may appear at the bottom of the screen are:
“OFF by remote shutdown” indicates the Remote Start/Stop feature is enabled and requires a remote start switch to be turned
on.
“OFF by Network” indicates the unit is part of a group and is off because of a grouping priority command such as a compressor
alarm or loss of airflow, or the BMS communication feature is enabled and the unit received a network signal to pause operation.
“OFF by Internal Alarm” indicates that the unit is off because of a group alarm condition. (Only active with grouped units.)
“Unit on CL Lockout” indicates cooling has been locked out while there is a demand for dehumidification because the
temperature is below the minimum temperature allowable for dehumidification (factory default setting is 4° F below setpoint).
4. After the initialization period expires, the controller enables the control output to the CW valve and signals it to open.
Following a 45-second time delay (to allow the valve to fully open) the fans are allowed to begin operating.
5. The Black Box logo in the display is replaced with a blower
symbol. The fans begin operating in stages with five-second
time delays. The middle fan starts first, then the upper fan, then the lower fan.
6. Following a 45-second time delay (after the first fan turns on) the controller polls the air proving switch. If adequate airflow is
detected, the controller begins proportionally controlling the output signals to perform cooling, humidification, and
dehumidification as defined by the system configuration. If there is no call for cooling at that time, the CW valve is returned to
the closed position.
Figure 4-13. Controller polls screen.
7. The controller records the date and time power is reinitialized in the alarm history log.
8. If the actual room conditions are not within the range of the programmed setpoints, the system will begin operating in the
mode(s) needed to reach the setpoints (cooling or dehumidifying). Symbols appear to indicate the active operating modes.
= Blower On
= Cooling Enabled (CW based units)
= Humidifying
= Dehumidifying
= CW Coil Flush Cycle On
9. Temperature and humidity alarms are masked out for 30 minutes to allow conditions to stabilize without triggering nuisance
alarms.
10. Operator interface to the menu loops is available from the Main screen by pressing the Program (Prg) key. The controller starts
a timer whenever a key sequence is initiated. Every time a button is pressed, the timer is reset. If there is no key activity for 60
seconds, the controller will return to the Main screen unless the Screen Lock feature is enabled in the Information menu loop
(see Section 4.5.2).