Retrotec Multi-Fan Blower Door - Manual (Page 21)

Page 21 of 37
©Retrotec Inc. 2015
6. Control Cable configurations that work best
The difference between the multi-fan configurations is how you connect the Speed Control Cables. The
configuration of your multi-fan setup depends on:
1. which models of Retrotec fans or Drives you are trying to connect,
2. which model of Retrotec gauges you are trying to connect, and
3. whether you want Individual or Common set point control (see section 3).
Most commonly, multi-fan setups use high output fans, so connections involving only 3300 series
Retrotec fans will be described in this section.
Table 1. Summary of Control Cable configurations illustrated in this section
Fan/Drive model Gauge model: Set point control Refer to:
3300 DM-2 Common Figure 22
3300 DM-2 Individual Figure 23
3350 DM-2 Common Figure 25 and Figure 26*
3350 DM-2 Individual Figure 27
3300 and 3350 DM-2 “Somewhat Common” Figure 28
3350 DM32 Common Figure 29
3350 DM32 Individual Figure 30
*Figure 26 illustrates the use of the Multi-fan Umbilical. If you
have three fans, you can make use of the Retrotec Multi-fan
Umbilical (part number DM241) which allows three fans to be
controlled from 75 feet away with only one Umbilical,
minimizing the tangle of cabling at the fans and gauges.

Tube diameters are small, making this umbilical small and
light.

Small diameter tubes eliminate pressure spikes when
accidently stepped on.

You can have your gauges right next to your computer,
giving you more control.

The protective sheathing eliminates errors due to the sun
shining on tubes.
While it is true that some gauges will yield errors when used with tubes over 50 feet and/or with small
diameter tubes, that is not true with the Retrotec gauge. Because the Retrotec gauge has an extremely
small diaphragm it is not affected even when tubes are 1000 feet long or more.
Figure 19: Multi-fan Umbilical to facilitate neat
multi-fan installations