How to Select Carbon Brushes for Motors and ... - Morgan AM&T

8
Electrographitic (continued)
Brush
Grade
N66
N964
R20X1
SA35
SA45
SA4542
SA4548
SA50
T300
T416
T500
T508
T550
T563
T566
T573
T583
T606
T652
T659
T758
Spec.
Res.
Ω-in.
(µΩ-m)
0.0026
(66)
0.0021
(53)
0.0004
(10)
0.0021
(53)
0.0026
(66)
0.0026
(66)
0.0025
(64)
0.0028
(71)
0.0008
(20)
0.0030
(76)
0.0030
(76)
0.0022
(56)
0.0029
(74)
0.0030
(76)
0.0030
(76)
0.0027
(66)
0.0022
(56)
0.0035
(76)
0.0030
(76)
0.0030
(76)
0.0027
(66)
Dens.
g/cm³
1.62
1.60
1.70
1.54
1.49
1.51
1.50
1.49
1.72
1.62
1.57
1.68
1.63
1.58
1.62
1.62
1.67
1.73
1.62
1.63
1.68
Trans.
Strength
lbf/in²
(kgf/cm²)
2800
(197)
3400
(239)
3000
(211)
2400
(169)
1450
(102)
1525
(107)
1500
(106)
1000
(70)
4000
(282)
2700
(190)
2000
(141)
4300
(303)
3900
(275)
2400
(169)
2500
(176)
3100
(218)
4100
(289)
3600
(253)
2700
(190)
4000
(282)
4700
(331)
Con-
tact
Drop
Friction
VH L
VH M
H M
VH L
VH L
VH M
VH L
VH L
H M
VH M
VH M
VH M
VH M
VH M
VH M
VH M
VH M
VH M
VH M
VH M
VH M
Surface
Speed
ft/min
(m/sec)
8000
(41)
8000
(41)
4000
(20)
8000
(41)
10000
(51)
8000
(41)
8000
(41)
10000
(51)
7000
(36)
8000
(41)
8000
(41)
8000
(41)
8000
(41)
8000
(41)
8000
(41)
7000
(36)
6000
(30)
7000
(36)
8000
(41)
8000
(41)
8000
(41)
Normal
Current
Density
A/in²
(A/cm²)
80
(12.5)
80
(12.5)
80
(12.5)
80
(12.5)
80
(12.5)
80
(12.5)
80
(12.5)
80
(12.5)
80
(12.5)
80
(12.5)
80
(12.5)
80
(12.5)
80
(12.5)
80
(12.5)
70
(11)
80
(12.5)
80
(12.5)
70
(11)
80
(12.5)
80
(12.5)
80
(12.5)
Description and Application
Recommended for:
Where a slight polishing action may be
required for controlling commutator bar
marking or other contaminants.
Low/variable humidity conditions and where
long periods of light loading are a factor.
Slip rings of wound rotor or synchronous
machines used in low humidity or difficult
filming conditions.
Where intermediate commutating ability is
required.
Where excellent commutating ability is
required. Used widely on industrial motors
and generators.
Where severe operating conditions such as
transient overloads and improper machine
adjustment are present and a slight polishing
action is needed.
Applications where SA45 would normally be
used but where increased filming ability is
required.
Machines where superior commutation is the
primary requirement.
24 to 80 volt DC machines where low
humidity and high loads are present.
Where excellent commutating and riding
properties are required. Applied on highvoltage
machines used in steel mills, paper
mills, dragline generators, etc.
Heavily loaded, difficult to commutate
machines. Long life at lower humidity.
General industrial and transportation
applications.
The plastics industry where good filming and
excellent commutation is necessary.
Wide variety of industrial applications where
excellent commutation is necessary.
Contaminated atmospheres seen in paper
mills and where load requirements are high.
Wide variety of industrial applications.
Medium duty industrial and general traction
motor application.
Where threading is a concern in
contaminated atmospheres and to minimize
friction chatter.
Where low humidity and selelctivity are
concerns.
Low friction and good commutation are
primary concerns.
High-speed transit car motors.
7