32
Commissioning and Maintenance
Maintenance of belt-driven fan unit
ELECTRICAL HAZARD AND DANGER FROM ROTATING UNIT PARTS!
OBSERVE PERSONAL PROTECTION MEASURES.
In doing so, be sure to observe the safety information on page 51.
DAMAGE TO UNIT
When the fan is at a standstill and the unit heater control valve (water, steam or
refrigerant) is open, temperatures occur inside the unit that are roughly equivalent to the
inlet temperature of the heating medium (normally around 90 °C). This causes damage
through deformation of plastic parts (particularly to plastic droplet eliminators, humidifier
honeycombs etc.).
Furthermore, fan and motor bearings with permanent lubrication may be damaged at
temperatures above 80 °C. Many electric built-in components (frequency inverters etc.)
may only be operated at temperatures up to a maximum of 40 °C – see also the relevant
manufacturer’s instructions.
The following maintenance and inspection steps must be carried out:
• Check that fans are securely mounted.
• Check fans for soiling, damage and corrosion.
• Check that anti vibration mounts are functioning correctly.
• Check that belt guards are functioning correctly, clean as necessary.
• Check impeller for imbalance.
Re-tensioning/renewing V-belt
Carry out the initial check after approximately 50 operating hours.
The subsequent checks depend on the operational load.
– For normal operation (roughly 8 hrs a day), perform check every 3 months.
– Define shorter intervals between checks where the number of operating hours is
greater.
Initial check:
Regular checks:
Belt
profiles
Diameter of
small disk (mm)
Force F
(N/belt)
SPZ
70 – 85
13 – 19
86 – 155
15 – 23
116 – 150
19 – 27
151 – 200
25 – 24
201 – 250
29 – 38
SPA
112 – 150
25 – 34
151 – 200
29 – 38
201 – 250
35 – 44
251 – 300
40 – 50
SPB
180 – 224
40 – 52
225 – 300
46 – 60
301 – 400
55 – 76
401 – 500
67 – 90
0
10
20
30
40
50
0
500
1000
1500
2000
2500
3000
Deflection x [mm]
Distance between axes A [mm]
