User manual

28
Sheave Alignment
Always shut off electrical power to the tower fan motor prior to
performing any inspections that may involve physical contact with
themechanicalorelectricalequipmentinoronthetower.Lockout
and tag out any electrical switches to prevent others from turning
thepowerbackon.Servicepersonnelmustwearproperpersonal
protectiveclothingandequipment.
• The motor sheave is to be positioned as close as possible to the motor
in order to minimize torque on the motor bushings.
• The motor and fan sheaves may have grooves that are not used. The bot-
tom surface of the motor and fan sheaves must be aligned within
1
⁄8" of
each other and level within
1
⁄2° (
1
⁄8" in 12") in order to not adversely affect
belt and sheave life.
• Alignment can be achieved by placing a straight edge across the top of
the sheaves making sure that it is level and measuring down to the bottom
surface of both sheaves at four points. See photo.
• The number of grooves on the motor and fan sheaves may not match
each other, or the number of grooves on the belt. Always install the belts
on the highest grooves on the fan sheave. Doing so will reduce the force
on the fan shaft bearings, thus increasing their life.
Maintenance
Motor Sheave
diameter
Used V-Belt
minimum
New V-Belt
maximum
3.4" - 4.2"
85cm - 105cm
4.9 lb
2.2 kg
7.2 lb
3.3 kg
4.4" - 5.6"
106cm - 140cm
7.1 lb
3.2 kg
10.5 lb
4.8 kg
5.8" - 8.6"
141cm - 220 cm
8.5 lb
3.9 kg
12.6 lb
5.7 kg
Warning
Bushing Fastener Torque ft·lb
ƒ
SH
1
⁄4
-
20 6
SDS
1
⁄4
-
20 6
SD
1
⁄4
-
20 6
SK
5
⁄16
-
18 13
SF
3
⁄8
-
16 22
E
1
⁄2
-
13 35
F
9
⁄16
-
12 65
Bushing Fastener
Torque Values