Retrotec DM-2 - Manual (Page 16)

Page 16 of 72
©Retrotec Inc. 2012
1. Press [Set Pressure] to activate the automatic control. Input the desired building pressure
using the DM-2 keypad and press [Enter] to start the fan.
2. The fan will accelerate until the input pressure has been reached, or the fan reaches 100%
speed. The fan will continue to hold at that pressure, regardless of changes to the
enclosure or room (i.e. opening/closing windows and doors, HVAC on/off, sealing, etc.).
3. Press [Exit] to stop the fan, and cancel the Set Pressure.
If the pressure is set to “0” Pa, the gauge will adjust the fan speed to bring the existing pressure to
zero. This can be used to neutralize pressures during specific tests. See the Retrotec DucTester
Operation & Testing manual for an example.
When numerical input is required, the [Set Pressure] key functions to input the number seven, [7] .
2.1.12 Set Speed
The gauge can automatically control the fan speed on Retrotec systems to achieve a
specific user-defined fan speed.
To use the Set Speed function
1. Press [Set Speed] to activate the automatic control.
2. Input the desired speed using the DM-2 keypad. Speed is input as a percentage, and can be
any value from 1-100.
3. Press [Enter] to start the fan. The fan will accelerate until the desired speed is achieved.
4. Press [Exit] to stop the fan and cancel the Set Speed, or press [Set Speed] [0] [Enter] to stop
the fan.
When numerical input is required, the [Set Speed] key functions to input the number eight, [8] .
2.1.13 Jog/Hold
The [Jog/Hold] key has two functions, Holding the display and Jogging the fan speed:
2.1.13.1 Hold

Freezes the display with the data currently displayed on the screen. Nothing will
change until the [Jog/Hold] key is pressed again to clear "Hold".

Can be activated at any time.

Allows the recording of instananeous results (eg. Flow, EqLA, PrB at precisely the same time)

Hold will also hold the Speed Control signal to the fan without allowing it to vary up or down. The
signal will be held until [Exit] is pressed which will shut off the fan.
The screen will display either "- - - - " or "Hold", unless it is doing a Set Speed or Set Pressure when it
will display either "- - - - ", "Jog" or "Hold".
To activate Hold:
1. Press [Jog/Hold] until "Hold" appears on the screen to freeze the screen and lock the data
currently displayed.
2. Press [Jog/Hold] again until "----" is displayed to unlock the screen.