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Chapter 4: E2 Controller
4.4.4.1.2 Temperature Proportionate Speed Control
The controller adjusts the speed of each fan proportionally for that zone to meet the supply air temperature setpoint. The
controller compares the variance of each temperature zone to the temperature setpoint and develops a proportional control
output to modulate the speed of each fan to meet the supply air temperature setpoint for that zone.
4.4.4.1.3 Manual Speed Control
The controller continually controls the speed of each fan to values manually entered in the system controller Control>Set>Fan
Control menu loop (Section 4.5.4.1) without regard to the temperature setpoint.
4.4.4.2 Static Pressure Control
The control of static pressure is used as a means to ensure the constant flow of air across the heat load in server containment
configurations. The controller is configured to control fan speed from 100% (full speed) to a minimum setting based on the total
system static pressure. Minimum and maximum fan speed settings are user adjustable in the Service menu. The static pressure is
either directly read by the controller as an analog input from a sensor or a static pressure input signal may be provided to the
controller from a BMS. See Section 4.5.4.1 for instructions on setting static pressure control.
4.4.5 Remote On/Off
For Remote On/Off operation, terminal positions are provided to connect a remotely located, On/Off switching control device. If
the A/C unit is turned on and the E2 controller receives a remote input signal to turn off the A/C unit, the controller disables all
control outputs and a message “Off by Remote Shutdown” appears in the main display screen. The A/C system will automatically
be reenabled when the remote On/Off signal calls for the A/C unit to turn back on.
The control device may be an On/Off switch, thermostat, or a humidistat. If customer provided, the remote On/Off control
contacts must be sized appropriately. The Remote On/Off contacts must have a minimal rating of 24 VAC. Refer to the electrical
drawing included with the A/C unit for the electrical specifications and for wiring details.
4.4.6 Dual Power Transfer Monitoring
As an option, two sources of input power may be used (see Section 1.6.5). With this feature the controller monitors switching
between two power sources, such as commercial power and generator backup. Each power source is monitored by a voltage
monitor (used on 1-phase systems) or a phase relay (used on 3-phase systems), one output of which goes into the power
switching circuit and the other output sent to the controller for monitoring purposes. If a power transfer occurs, the controller
provides an alarm message and the alarm display indicates which power source failed.
4.5 Menu Screens
4.5.1 Main Menu
Figure 4-20. Main menu.
The Main Menu is accessed from the Main screen by pressing the key. The Main Menu screen provides a complete listing of
the menu loops that are available. You may scroll through the menu categories using the Up and Down arrow keys. From
the Main Menu screen, you may select from among the following standard menus:
“Info” displays basic read-only status information. Allows you to monitor system operational parameters. No password is needed
at this level.
“Alarm Log” displays all alarms and “power-ups” in sequential order with a time and date stamp. No password is needed at this
level.