Checking The Brush - Yamaha F30B 2018 Service Manual

3. Measure:
• Commutator undercut "a"
Below specification  Replace the arma-
ture.
Standard commutator undercut
1.50 mm (0.0591 in) (F30A,
F30BET,
F40FET, F40HA)
Wear limit
1.35 mm (0.0532 in) (F30A,
F30BET,
F40FET, F40HA)
4. Check:
• Armature continuity
Out of specification  Replace the arma-
ture.
a
b
Digital circuit tester
90890-03243
Digital multimeter
YU-34899-A
Armature continuity
"a" "b"
a
F30HA, F40A,
F30HA, F40A,
d
c
"c" "d"

Checking the brush

1. Measure:
• Brush length
Below specification  Replace the brush.
a. Standard brush length
b. Wear limit
Standard brush length
7.00 mm (0.2756 in) (F30A,
F30BET,
F40FET, F40HA)
Wear limit
3.5 mm (0.14 in) (F30A, F30BET,
F30HA, F40A, F40FET, F40HA)
2. Check:
• Circuit breaker continuity
No continuity  Replace.
Do not touch the bimetal "a". Otherwise,
the operation of the circuit breaker could be
affected.
3. Check:
• PTT motor base
Cracks/damage  Replace the PTT motor
assembly.
9-35
PTT motor
b
a
F30HA, F40A,
a