GE GEH-5304A - Manual (Page 19)

GEH-5304A
19
2. Noise and Vibration
Check for unusual vibration or noises that might indicate rubbing or interference.
Vibration of new machines at the bearing housings, as measured by a vibration meter, should not ex-
ceed the values shown in Table 8. (Measurements are according to NEMA MG 1-12.06 and MG 1-
12.07.)
The most likely cause of vibration in new machines is misalignment due to improper installation,
loose foot bolts, uneven shimming under feet, or damage to machine during shipment or installation.
Current ripple due to a rectified power supply may also be a source of vibration and audio noise.
Table 8
Maximum Amplitude
(in Inches)
RPM (Peak to Peak)
3000-4000 incl. .001
1500-2999 incl. .0015
1000-1499 incl. .002
999 and below .0025
3. Inspection After Short Time in Service
New machines may smell warm or have the odor of varnish, but should not smell scorched.
After a machine has been operating for a short time, an inspection should be made to ascertain that
there have been no changes since installation. Check for increased vibration, signs of change in
alignment or foundation settling, bolts that may have loosened, rubbing parts, loose connections and
worsened commutation. Proper steps must be taken to correct the trouble. Also, check the condition
of air filters on blower ventilated machines. The amount of dirt in the air varies widely between in-
stallations.
V. MAINTENANCE
High voltage electric shock may cause serious or fatal injury. Disconnect power
before touching any internal part. High voltage may be present even when the
machine is not rotating. If used with a rectified power supply, disconnect all AC
line connections to the power supply. With other power supplies, disconnect
all DC line and field connections. Also, disconnect power from auxiliary de-
vices.
Ground the machine properly to avoid serious injury to personnel. Grounding
must be in accordance with the National Electrical Code and consistent with
sound local practices.
Replace covers and protective devices before operating.