Du Pont SORVALL RC-5 Service Manual page 129

Warning:
Only install the correct thickness
brush. If the wrong brush is cho-
sen the centrifuge may not run and
the motor may be damaged.
P/N: 50589-3
INSTRUCTIONS
RC-5B / RC-5C Preventative Maintenance Kit
(Kit Catalog No. 12010)
7. Remove the motor brushes and inspect the motor commutator. The
commutator should be a smooth shiney copper color devoid of pits and
grooves. If the commutator is damaged, replace the motor.
RC-5B & RC-5C centrifuges
8. With the brushes removed turn the gyro shaft by hand and check for
smooth noise free rotoation. If the motor shaft feels rough or makes
noise disconnect the motor from the gyro and determine weather the
gyro or the motor are the cause of the problem. Check the motor cou-
pling for any deformities. If the coupling is damaged, replace it with
part number 12345. If the motor bearings are damaged, replace the
motor using the chart above as a guide. If the gyro is the cause of the
problem, replace the gyro ordering part number 12817.
9. If the motor contains carbon brushes replace the brushes after first
comparing the brushes that were removed with the new brushes that
are included with the PM kit (12010). Discard the brushes that were
removed from the motor.
12884
74196
10. Inspect the smaller brush warning spring to insure proper operation.
11. Inspect the foam ring inside the silencer assembly located under the
centrifuge chamber (motor shroud). Insure that the foam ring that is
located at the bottom of the upper silencer assembly is place and intact.
If the foam ring is missing or damaged replace it using the foam ring
kit part number 74342.
12. Using a DVM (digital volt meter) check the continuity of the ground
wire on the motor assembly. The resistance from the ground pin on
the motor cable to the motor frame should be less than 0.1 Ω.
13. Inspect the tapered pins on the gyro cone drive adapter. Replace any
damaged pins with the new pins (204742) that are supplied with the
PM kit (12010).
for the
Centrifuge
1/4" thick brush kit
3/8" thick brush kit
Motor
12991
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