Startup; Adjustment - Nederman Airflow Alarm Kit Manual De Instrucciones

When monitoring
One single workplace
A group of workplaces
The pressure switch can be mounted on the air duct.
NOTE! When drilling in air ducts, safety regulations must be kept in mind.
The hose is connected to the hose connection on the pressure switch marked
with a minus (-) sign. Nothing is connected to the hose connection marked
plus (+) atmospheric pressure.
4.4

Startup

When the fan starts, the alarm is activated, and the ALARM LED remains lit
until the required pressure is reached. The ON LED is also lit.
4.4.1

Adjustment

1. A suitable part of the duct is selected, and a hole for the protection filter
is drilled close to the last connection point. See section 4. Installation
above.
2. The maximum airflow according to the order acknowledgement,
technical specifications etc. must be determined and the corresponding
air velocity calculated.
3. The air velocity is measured with the planned number of extraction
points open. If the airflow is larger than (V
example, this can be done by inserting a plate in front of the fan outlet
flange to reduce the airflow until the airflow (V
4. At this airflow, the static pressure at the monitoring point (PS
measured, and the pressure switch is set 10% lower, see figure 4.
If the pressure switch measuring range does not cover the setting
value required, the pressure switch is replaced by one with a relevant
measuring range.
5. The main airflow is reduced slowly by inserting the plate in the fan outlet
flange until the alarm is released.
6. The air velocity is measured and the airflow is calculated. If it is between
90 and 95% of the airflow specified, the adjustment has been completed.
7. If the airflow is less than 90% of the airflow specified, set pressure switch
5% higher, and repeat item 5.
8. If the airflow is higher than 95% of the airflow specified, set pressure
switch 5% lower, and repeat item 5. It might be necessary to remove the
plate in front of the fan outlet flange.
Location
Between dust extraction point, such as a suction hood, and a
connection to the duct system.
Close to the connection point farthest away from the fan. See figure
3.
Airflow Alarm Kit
), reduce the airflow. For
0
) planned is reached.
0
) is
0
EN
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