Howden Roots Tri-RAM 409, Installation, Operation & Maintenance Manual

9

GEA19684  ISRB_2008 rev._11.15

Troubleshooting 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 published perfor-

mance.
Compare actual rotation with Figure 1, change driver if wrong.
Check piping, valves, silencer to assure open flow path.

Low capacity

4
5

6
7

Speed too low
Excessive pressure 

rise
 

Obstruction in piping
Excessive slip

See item 1, if belt drive, check for slippage and re-adjust ten-

sion.
Check inlet vacuum and discharge pressure and compare with 

published performance.
See item 3.
Check inside of casing for worn or eroded surfaces causing ex-

cessive clearances

Excessive power

8
9

10

11

Speed too high
Excessvie pressure 

rise
Impeller rubbing
 

Scale , sludge, rust or 

product build up

Check speed and compare with published performance.
See item 5
Inspect outside of cylinder for high temperature areas, then check 

for impeller contact at these points. Correct blower mounting, drive 

alignment.
Clean blower appropriately

Damage to bearings 

or gears

12
13
14
15
16

Inadequate lubrica-

tion
Excessive lubrica-

tion
Excessive pressure 

rise
Coupling misalign-

ment
Excessive belt ten-

sion

Check oil sump levels in gear and drive end headplates
Check oil levels. If correct, drain and refill with clean oil of recom-

mended grade.
See item 5.
Check carefully. Re-align if questionable.
Re-adjust for correct tension.

Vibration

17
18
19
20

21
22
23
24

Misalignment
Impellers rubbing
Worn bearings/gears
Unbalanced or rub-

bing impeller
Driver or blower 

loose
Piping resonances
Scale/sludge build-

ups
Casing strain

See item 15
See item 10
Check gear backlash and conditions 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 securely.
Determine whether standing wave pressure pulsations are present 

in the piping.
Clean out interior of impeller lobes to restore dynamic balance.
Re-work piping alignment to remove excess strain.

Driver stops, or will 

not start

25

26

Impeller stuck
 

Scale, sludge, rust or 

prodcut build-up

Check for excessive hot spot on headplate or cynlinder. See 

item 10. Look for defective shaft bearing and/or gear teeth.
Clean blower appropiately

Excessive breather
Blow-by or exces-

sive oil leakage to 

vent area
Excessive oil leak-

age in vent area

27
28

29

30
31

32

Broken seal
Defective O-ring
 

Defective/plugged 

breather
Oil level too high
Oil type or viscosity 

incorrect
 

Blower running hot

Replace seals
Replace seals and O-ring
 

Replace breather and monitor oil leakage
 

Check sump levels in gear and drive headplates
Check oil to ensure it meets recommendations. Drain then fill 

with clean oil of recommended grade.
Recommended oil temperature can be found on page 6 of this 

manual. The blower must be operated within the conditions of 

this manual.

GEA19684_ISRB-2008_Tri-RAM_rev02.16.indd   9

15/02/2016   11:17:05