Repair manual

Troubleshooting the Vibration System RD 27
wc_tx000953gb.fm 78
Continued from the previous page.
8. Press the vibration ON/OFF switch to activate the vibration and measure the
relief and operating pressures. The relief pressure is the pressure shown as
soon as the vibration is turned on. The system will then settle into operating
pressure. Record these two pressures.
Is an operating pressure of 120–152 bar (1800–2200 psi) measured?
9. Repeat the test with the drum vibration mode switch in the dual-drum position.
Is an operating pressure of 248–276 bar (3600–4000 psi) measured?
To help diagnose possible problems with the vibration system, compare the results
from operating pressure, relief pressure, and exciter speed using the chart below.
N = Normal, L = Low, H = High
Result The vibration operating and relief pressure has now been checked.
Yes ____ No ____
The vibration system operating pressure is
OK.
The vibration system operating pressure is
abnormal. See chart.
Yes ____ No ____
The vibration system operating pressure is
OK.
The vibration system operating pressure is
abnormal. See chart.
Operating
Pressure
Pump Relief
Pressure
Exciter
Speed
Probable Cause
N N N System OK
H N N or L Exciter bearings or motor binding
N or L N L Exciter motor worn
L L L Exciter pump damaged or worn, relief
valve defective, or needs adjusting