TM 9-2320-279-34-3
Arctic Heater Kit Maintenance Instructions (Cont)
WARNING
Compressed air used for cleaning purposes will
not exceed 30 psi (207 kPa). Use only with
effective chip guarding and personal protective
equipment, goggles, shield, and gloves.
(a)
Cut commutator of armature (1) as
required on lathe. When cutting
commutator, cut no more than
0.005 in. (0.13 mm) at a time to
remove scoring, pits, burrs, or to
return commutator to round. Then
make final cut of 0.002 in. (0.051
mm). Undercut commutator with a
0.025 in. (0.63 mm) or less slot
width. Blow off all loose copper and
mica with compressed air.
(b)
Polish commutator of armature (1)
with abrasive paper. Blow off all
loose debris with compressed air.
(3)
Inspect brush and spring assemblies for brush chips, excessive brush wear, spring distortion, and
broken or frayed pigtails. If brush has more than minor chips in it or is less than 0.300 in. (7.620
mm) in length, replace brush spring assembly If spring is distorted or has lost its resilience,
replace brush spring assembly. If pigtail is frayed or broken, replace brush spring assembly.
(4)
Replace unserviceable parts.
Change 3
21-7
