14
GEA30580_Rev_11.15
Trouble Shooting Checklist
Trouble
Item
Possible Cause
Remedy
No flow
1
2
3
Speed too low
Wrong rotation
Obstruction in piping
Check by tachometer and compare with speed on
Roots Order Acknowledgement�
Compare actual rotation, change driver rotation if
wrong�
Check piping valve, silencer, to assure open flow
path�
Low Capacity
4
5
6
7
Speed too slow
Excessive pressure rise
Obstruction in piping
Excessive slip
See Item 1�
Check inlet vacuum and discharge pressure and
compare these figures with specified operation
conditions on order�
See Item 3�
Check inside of casing for worn or eroded surfaces
causing excessive clearances�
Excessive Power
8
9
10
Speed too high
Excessive pressure rise
Impeller rubbing
See Item 1�
See Item 5�
Inspect outside of cylinder for high temperature
areas, then check
for impeller contact at these points� Look for
excessive scale build-up� Correct blower mounting
drive alignment�
Overheating of bearings
or gears
11
12
13
14
Inadequate lubrication
Excessive lubrication
Excessive pressure rise
Coupling misalignment
Check oil sump levels in end covers�
Check oil levels� If correct, drain and refill with clean
oil or
recommended grade
See Item 5�
Check carefully� Realign if questionable�
Vibration
15
16
17
18
19
20
Misalignment
Impellers rubbing
Worn bearings/gears
Unbalanced or rubbing
impellers
Driver or blower loose
Piping resonance
See Item 14�
See Item 10�
Check gear backlash and condition of bearings
and replace as indicated�
Scale or process material may build up on casing
and impellers or inside impellers� Remove build-up
to restore original clearances and impeller balance�
Tighten mounting bolts accurately�
Determine whether standing wave pressure pulsa-
tions are present in the piping� Refer to Sales
Office�
Driver stops or will not
start
21
Impeller stuck
Check for excessive hot spot on headplate or cylin-
der� See Item 10� Look for detective shaft, bearing
and/or gear teeth�
Excessive breather
blowby or
excessive oil leakage to
vent area
22
Broken seal
Replace seals
GEA30580 Roots 827 DVJ IOM Manual_rev.02.16.indd 14
15/02/2016 12:15:35
