Troubleshooting & repair, Shunt coil and series coil resistance tests, Dc exciter test (continued) – Lincoln Electric PIPELINER 200 User Manual
Page 86
TROUBLESHOOTING & REPAIR
F-16
F-16
PIPELINER® 200
WHITE
FLEX
LEAD
SMALL
FLEX
LEAD
SOLID
LEAD
WARRANTY
FIGURE F.3 – BRUSH HOLDER LEADS
SHUNT COIL AND SERIES COIL
RESISTANCE TESTS
7. Turn the engine OFF.
8. Using the 3/8" nut driver, disconnect the two leads
from the left side brush holder. See Figure F.3.
Separate the two leads. One will be a larger
"solid" lead (series coil). The other will be a small-
er flex lead (shunt coil).
9. Using the 3/8" nut driver, remove the two flex leads
from the right side brush holder.
Note: Two coils make up a set (L8707), and each coil
consists of two coils, wound together. An Exciter
Shunt Field Coil and an Exciter Series Coil.
10. The coil leads should be disconnected from the
positive and negative brush holder and also the
bolted connection within the exciter bracket that
connects T12 to the RED lead.
11. Using the Ohmmeter, measure the Exciter Series
Coils from the T12 and T2 (heavy stiff magnet
wire) and the Exciter Shunt Field Coils from T4 and
T14 (fine stranded wire) to a good frame ground.
The resistance should be very high (500k Ohms or
higher). This indicates that the coils are not
grounded. If the resistance reading is less than
500k Ohms, this indicates a grounded condition
and replacement should be considered.
12. Using the Ohmmeter, measure Exciter Series
Field Coils from connection T12 to connection T2.
The resistance should be .276 to .296 Ohms.
Measure with the Ohmmeter the Exciter Shunt
Field Coils between T4 and T14, The resistance
should be 127.0 to 133.0 Ohms. If resistance is
very low, the coils are shorted. If coils are warmer
or colder than 25 degrees Celsius, the resistance
will be considerably higher or lower. If coil resis-
tances vary significantly, REPLACEMENT MAY
BE NECESSARY.
13. If the shunt and series coils are good, and the
exciter is not operating properly, the exciter arma-
ture may be faulty. Replace the exciter armature.
14. After the test and repairs are completed, install the
exciter cover using the 3/8” nut driver.
DC EXCITER TEST (continued)
EXCITER SHUNT FIELD
EXCITER
ARMATURE
EXCITER SERIES FIELD
120 VOLTS
DC
#2
#1
T
T
T
T
T
T
T
T
12
11
1
2
4
3
13
14
-
+
RED LEAD -