TF7039GB_A_NOT
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6.2.2.
DIFFERENTIAL PRESSURE CONTROL
The device is equipped with a pressure control. This is mounted
under the hood directly behind the maintenance opening. To gain
access, the eight screws must be loosened (pictures on the
right).
The maintenance opening cover must be secured
against falling when loosening the screws.
The differential pressure control has an internally connected discharge port for receiving the static negative
pressure in the unit suction chamber next to the filter unit and a discharge port for receiving the ambient
pressure under the port cover. The position of the pressure measuring hoses and pressure connections must
not be changed. Care must be taken that the transparent pressure measuring hoses are not bent or otherwise
disconnected or blocked over their entire length. The opening at the end must remain free. Otherwise the
unit’s intended function may be affected.
Before opening the controller, the unit must be disconnected from the mains and secured
against being switched on again. Wait for the fan impeller to come to a standstill.
A
DIP switch S1 “Pressure setpoint”
B
DIP switch S2 “% setback”
C
DIP switch S3 “Hall sensors”
D
“Network” LED
E
Pressure indicator
F
Fuses
G
Terminal X5 “Mains power supply”
H
Terminal X4 “Error message”
I
Terminal X3 “ON”, “Setback”
J
Terminal X2 “Control signal”
K
Terminal X1 “External”
L
Pressure sensor
M
“Setback mode” LED
N
“Error” LED
The pressure control regulates the negative pressure on the suction side by adjusting the fan speed to an
adjustable fixed pressure level relative to the atmospheric pressure. The pressure regulator is thus the heart
of a demand-driven ventilation system that automatically reduces the fan output and thus the power con-
sumption when the air volume requirement is low. As an output signal, the pressure control module supplies
DC voltage between 0-10 V, which serves as input for the fan motor (control signal).
The control operation is monitored. The signals from the pressure sensor are evaluated for this purpose. If a
too large deviation of the signals from the setpoint value is detected for longer than five minutes (optionally
