Belt Tension Measurement With Frequency Meter; Belt Tension Adjustment - Sullair ShopTek ST4 User Manual

6: Maintenance
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
Figure 6-9: Belt tension frequency meter
Refer to Figure 6-9. 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
46
ShopTek™ ST4, ST5, ST7, ST11, ST15 Three-phase 60 Hz User Manual
88292018-236 R00
Subject to EAR, ECCN EAR99 and related export control restrictions.
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 Figure 6-10 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.