14 Set fan speed
14.1 Press
[Set Speed]
[10-100] [Enter]
on the
DM-2 to set any speed from 10 to 100%.
Example:
Press
[Set Speed] [25] [Enter]
to set the fan
speed to 25%.
Tip
Monitor “PrA” to ensure that the pressure does not exceed
90Pa.
Tip
Press
[Exit]
to turn the fan off.
14.2 Press
[Jog/Hold]
until “Jog” appears. This
enables manual fan speed adjustment.
14.3 Use
[
S
] [
T
]
to adjust the fan speed up or
down.
Tip
Click once to change speed by 1%, hold button to
increment by 5%.
15 Set pressure automatically
15.1 Press
[Set Pressure]
[10-90] [Enter]
. The
DM-2 will control the fan to achieve the set
pressure.
Example:
Press
[Set Pressure] [50] [Enter]
to instruct
the DM-2 to attempt to achieve 50Pa building pressure.
15.2 Press
[Jog/Hold]
until “Jog” appears, to
enable manual pressure adjustment.
Tip
Click once to change pressure by 5 Pa, hold to increment
by 10 Pa.
Tip
Press
[Exit]
to turn the fan off.
16 Viewing flow at another pressure
16.1 Press
[@ Pressure]
until “@...” appears.
Flow is now calculated at the pressure
displayed after the “@”.
Example:
2190 cfm is the flow rate that would occur if the
exact test pressure of 50 Pa was achieved.
Tip
It is difficult to achieve an exact test pressure especially
under windy conditions. Use “@ Pressure” to improve
accuracy; flow at the pressure following the “@” sign will
be displayed.
In
[Set Pressure]
mode, the “@ Pressure” can change
according to the target pressure which is very useful
when setting several different test pressures.
“Too Low” is displayed
If the pressure (PrA) has been reached, but “Too
Low” appears, the fan is running too slowly to
measure flow.
1. Press
[Exit]
to stop the fan.
2. Add the next smaller range plate.
3. Change the
[Range Config]
to match.
4. Restart the fan and try again.
Cannot reach target pressure (50Pa)
If the fan reaches 100% speed before reaching the
target “PrA” pressure:
1. Press
[Exit]
to stop the fan.
2. Remove a range plate, and change the
[Range
Config]
to match.
3. Start the fan and try
again.
Still cannot achieve target pressure
If the fan reaches 100% speed before reaching the
target “PrA” pressure and all of the range plates
have been removed:
Press
[@ Pressure]
to calculate the flow required to
establish the target pressure.
Example:
2200 cfm is the flow rate that would occur at 50
Pa even though only 42 Pa was achieved.
17 Flow at the pressure on channel “PrA”
17.1 Press
[@ Pressure]
until “@...” disappears.
Flow is now calculated at the pressure
displayed.
Example:
2262.8 cfm is the flow rate that occurred when
a test pressure of 53.0 Pa was achieved.
Tip
CFM50 or cfm at 50 Pa is commonly used in the USA.
Simply establish 50 Pa and read the flow.
Tip
The default @ Pressure settings can be changed by using
[Setup]
.
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