fisair DFRA Series, User Manual

Page: 44 / 68

User Manual DFRA Series |
44
9.9 Flow adjustment.
Steps for adjusting the process air flow (if the differential pressure sensor is not
available):
1) Measure the differential pressure of the differential pressure ports on the
front of the control panel with a pressure gauge.
2) A. Direct drive fan (constant speed):
By opening and closing the damper, the process air pressure drop is
established according to the corresponding values in the pressure drop
table to obtain the nominal process air flow.
B. Plug type fan (variable speed):
The air flow rate is adjusted manually using the potentiometer installed
in the unit panel. Use the pressure taps on the front of the unit to
measure the pressure drop and adjust until the pressure loss
corresponds to the desired process nominal air flow
The flow rate can also be regulated (in the case of a plug type fan), as
explained in the sub-
section “Flow rate calculation via differential fan
suction pressure” located at the end of this section.
3) Repeat steps 1 and 2) A. for the reactivation air.
Pressure Taps
P- Reactivation air P
+
P
+
Process air P-