JOHNSON CONTROLS
10
GUIDELINES
GUIDELINES FOR INTERPRETING THE CLASSIFICATIONS ON THE SEVERITY CHART
Smooth:
Alignment, balance and the integrity of the support structure must be near perfect and the vibration from sources other
than the fan equipment must be low.
Good:
Requires reasonable care on installation, proper foundation, good balance on the rotating components and good alignment
of the running gear.
Fair:
Fan equipment can operate in this region, but imperfections are indicated.
Slightly Rough:
Requires service. Continued use in this condition will reduce equipment life. Monitor equipment for deterioration.
Rough:
Requires service. Dangerous operating conditions for fan equipment. Shut equipment down.
Shut Down:
Do not operate fan equipment. Potential for catastrophic failure.
KA
EP-
OT-
KA
EP
-
SLI
M -
T
NE
ME
CA
LP
SI
D
N
OI
TA
RBI
V
Vibration Frequency* - CPM
KA
EP
-
CE
S/
NI -
YTI
C
OL
EV
N
OI
TA
RBI
V
60
50
40
30
20
15
10
8
7
1.5
6
5
4
3
2
1.0
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.05 IN/SEC
0.10 IN/SEC
0.20 IN/SEC
0.80 IN/SEC
0.40 IN/SEC
00
3
00
4
00
5
00
6
00
7
00
8
00
01
00
9
00
21
00
51
00
81
00
02
00
03
00
63
00
52
Values are for filtered
readings taken on the
bearing caps.
Shut Down
Rough
Slightly Rough
Fair
Good
Smoot
h
*Frequency corresponds to RPM when dynamic imbalance is the cause of vibration.