iO- -400 Electronic Static Pressure ModuleESP
Installation & Operation
Instructions
INTRODUCTION
The iO- -400 is designed to work with any forced air zone control system capable of usingESP
conventional 24 Volt, 3-wire, floating point, motorized zone dampers. The module will handle up to four
zones. The same transformer used to power the zone control panel is also used to provide power to
the iO- -400. The module uses a iO- -400- pressure sensor that is installed in the mainESP ESP PS
discharge air plenum of the system.HVAC
SEQUENCE OF OPERATION
As zone dampers open and close, the iO- -400- Static Pressure Sensor continuously monitorsESP PS
the system static pressure. If the static pressure goes above the static pressure setpoint, the panel will
send a signal to all non-calling zone dampers to start to open to a point where the static pressure
setpoint is not exceeded. The small amount of air allowed to bleed into non-calling zones eliminates
air noise and assures proper airflow through the system. This also prevents coil freeze up andHVAC
high temperature issues. When all calls are satisfied, all zone dampers will go to the full open position.
INSTALLATION
1. Make sure all power is disconnected to the equipment and zoning panel.HVAC
2. Remove the iO- -400 cover and locate the panel on a flat, non-condensating, vertical surfaceESP
near
the zone control panel that will facilitate ease of access and wiring. Use appropriate anchors and
screws to secure the panel to the surface.
3. Run a 3-wire cable from each zone damper to the , C, terminals on the iO- -400.PC PO ESP
Strip 1/2” insulation off of each wire. Confirm the Power Close, Common and Power Open
wires and then push each wire into the terminals on the iO- -400. Repeat this step forESP
each zone damper in the system.
4. Run a length of 18-2 thermostat wire from the Power Close and Power Open terminals on the
zoning panel to the and terminals on the iO- -400. Make sure that the wire leads to thePC PO ESP
iO- -400 terminals have 1/2” insulation stripped off and then push each wire into the terminalESP
block. Repeat this step for each zone damper in the system.
5. Run a length of 18-2 thermostat wire from the 24 volt power terminals on the zoning panel to the
24 ‘R’ and ‘X’ terminals on the iO- -400. Make sure that the zoning panel 24 volt hot andVAC ESP
common match the ‘R’ Hot and ‘X’ Common on the iO- -400.ESP
6. Drill a 9/32” diameter hole in the middle of the main discharge air plenum prior to any zone dampers
or duct transitions. Take the iO- -400- Pressure Sensor probe and install it with the arrow inESP PS
the direction of airflow. Mount the iO- -400- Pressure Sensor in an accessible location withESP PS
the diaphragm in the vertical position. Use the supplied plastic tubing and attach one end to the
sensor probe and the other end to the ( ) high pressure fitting on the pressure sensor. RunP1+
conventional 8-2 thermostat wire from terminals 2 and 3 on the pressure sensor to the 1 andPS
2 terminals on the iO- -400 panel. The terminals are not polarity sensitive. (See wiringPS ESP
diagram on page 3)
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