6: Maintenance
ShopTek™ ST4, ST5, ST7, ST11, ST15 Three-phase 60 Hz User Manual
88292018-236 R00
46
Subject to EAR, ECCN EAR99 and related export control restrictions.
9. Average the three measurements to obtain
the true belt tension.
10. Repeat for remaining belts.
11. Compare the results to the belt tension spec-
ification in
Table 6-1
and adjust if necessary.
6.8.2
Belt tension measurement with
frequency meter
Refer to
. Follow instructions as follows:
1. Turn on the meter.
2. Hold the meter so that the probe is > 10 mm
(
⅜
") away from the belt being tested. Do not
touch the belt with tester probe.
3. Pluck a single belt at the midpoint between
the motor and compressor unit pulleys. Try
not to disturb any adjacent belts, as this will
give a false reading. As the probe detects a
vibration, the meter will display the fre-
quency. Record data.
4. Rotate the motor pulley through at least one
complete revolution and measure the belts
again, recording the results.
5. Repeat step 4 for a total of 3 measurements.
6. Average the three measurements to obtain
the true belt tension.
7. Repeat for remaining belts.
8. Compare the results to the belt tension spec-
ification in
Table 6-1
and adjust if necessary.
6.8.3
Belt tension adjustment
Refer to
and
Figure 6-11
.
Adjust the belt tension according to the following proce-
dure:
1. Shut down the compressor and isolate all
electric power.
2. Open the side panel and remove belt guard.
3. Loosen the locking nut.
4. Loosen the four compressor unit mounting
plate bolts ¾ of a turn.
5. Adjust the belt tension by turning the jacking
nut clockwise to tighten or counterclockwise
to loosen.
6. Measure belt tension and ensure it meets the
specifications in
Table 6-1
.
7. Tighten the locking nut.
8. Tighten the four compressor unit mounting
plate adjusting bolts.
9. Ensure that the discharge hose is not kinked,
bent, or has been placed under undue stress
or strain.
10. Replace the belt guard and the side panel.
Figure 6-9: Belt tension frequency meter