Greenheck SFD, SFB, SWB and SWD (455308) - Manual (Page 5)

Centrifugal Utility Fans 5
®
GOOD POOR
POOR
FAIR
7
o
MAX.
POOR FAIR
POOR FAIR
One
Impeller
Dia.
GOOD
Should be at least
1/2 Impeller Dia.
FAIR
Not Greater than
60
o
Including Angle
POOR
POOR FAIR GOOD
POOR
Turning
Varies
Affect of Installation on
Performance
Restricted or unstable flow at the fan inlet can cause
pre-rotation of incoming air or uneven loading of the
fan wheel, yielding large system losses, increased
sound levels and structural failure of the fan wheel.
Free discharge or turbulent flow in the discharge
ductwork will also result in system effect losses.
These examples show the system layout and inlet
and discharge configurations which can affect fan
performance.
Pre-Starting Checks
The adjustable motor pulley is set at the factory for
the fan RPM specified by the customer. Fan RPM can
be increased by closing or decreased by opening the
adjustable motor pulley. Multigroove variable pitch
pulleys must be adjusted an equal number of turns
open or closed. Any increase in fan speed represents
a substantial increase in load on the motor.
To avoid motor overheating and possible burnout,
motor load amperes should always be checked and
compared to nameplate rating when fan speed is
increased.
Alignment of Pulleys and Belts
Check pulleys and belts for proper alignment to avoid
unnecessary belt wear, noise, vibration and power
loss. Motor and drive shafts must be parallel and
pulleys in line as shown in Figure 1.
CORRECT WRONG WRONG WRONG
Figure 1
DANGER
Always disconnect, lock and tag power source
before installing or servicing. Failure to disconnect
power source can result in fire, shock or serious
injury.
CAUTION
When servicing the fan, motor may be hot enough
to cause pain or injury. Allow motor to cool before
servicing.
CAUTION
Precaution should be taken in explosive
atmospheres.
DANGER
Pour écarter les risques d’incendie, de choc
électrique ou de blessure grave, veiller à toujours
débrancher, verrouiller et étiqueter la source de
courant avant l’installation ou l’entretien.
ATTENTION
Lors de toute intervention sur la soufflante, le moteur
peut être suffisamment chaud pour provoquer
une douleur voire une blessure. Laisser le moteur
refroidir avant toute maintenance.
ATTENTION
Faire preuve de précaution dans les atmosphères
explosives.