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TK 61555-2-MM-EN
Belts should be regularly inspected during unit pretrip inspections for wear, scuffing, or cracking.
Belt tension should also be checked during scheduled maintenance inspections. Correct belt
tension is critical for correct unit operation. Belts that are too loose will whip and belts that are
too tight put too much strain on the belt fibers and bearings.
SLXi have both manual and automatic belt adjustment. SLXi units have an automatic tensioning
polygroove belt system driving the condenser and evaporator fanshaft. The lower polygroove
belt runs from the engine or electric motor to the intermediate jackshaft. The upper polygroove
belt runs from the intermediate jackshaft to the fanshaft and includes the drive for the alternator.
Additionally it has special procedures to facilitate easy belt changes.
New belts should be tensioned cold and re-tensioned cold after 10 hours of unit operation.
Using Thermo King Frequency Gauge (See Tool Catalog) is the best method to check belt
tension. Other commercially available tension gauges that measure the frequency or the tension
in pounds are also acceptable.
N
No
otte
e:: When using the frequency gauge P/N 204-1903, place the probe near the belt with the LED
shining on the belt. Pluck the belt with a metal tab as shown below to get an accurate
reading. Take three readings and average them.
Figure 42.
Using Frequency Gauge P/N 204-1903
1.
Probe
2.
Metal Tab
N
No
otte
e:: Do not attempt to remove or install belts without loosening adjustments. Belts that are
installed by prying over pulleys will fail prematurely due to internal cord damage.
