7
4. TEST OF THE SYSTEM AND CONTROL OF THE AIR VOLUME TO THE OUTLET GRILLES
The unit is prearranged to supply an external static pressure of
about 5 mm. Too high resistances in the air distribution system
can cause an exceedingly small air volume to the outlet grilles.
This trouble can be solved by increasing the fan speed as follows:
Open the cover of the electrical junction box. Take out the booster
cable clamped in the box. (fig. 4-1)
Disconnect the fan motor plug in the electrical box and insert
the booster cable as a cable extension between the motor plug
and the socket from the PCB. The external static pressure will
increase to 7 mm w.g. Check static pressure and air flow rate
on the fan performance graph. (fig. 4-2)
Fan motor
Fan motor
Booster cable
Booster cable
Connector motor cable (at the supply)
Fig. 4-1
Fig. 4-2
0
2
4
6
8
10
200
400
600
800
1000
H
HH
M
L
0
2
4
6
8
10
300
500
700
900
1100
1300
1500
L
M
H
HH
DSAVM9X/12X
DSAVM18X
m
3
/h
m
3
/h
EXTERNAL
ST
A
TIC PRESSURE (mmW
.G.)
EXTERNAL
ST
A
TIC PRESSURE (mmW
.G.)
H = High fan speed
L = Low fan speed
HH = Very high fan speed
M = Middle fan speed
H:
Standard supplied unit. Available fan speeds: Low-Middle-
High (L - M - H). Max. static pressure: about 5 mm
HH:
Unit with cable extension of the fan motor (booster cable).
Available fan speeds: Middle-High-Very high (M - H - HH).
Max. static pressure: about 7 mm
EG