Generac Power Systems 16 kW NG User Manual

AC GENERATORS
PART 2
Page 55
Section 2.4
Diagnostic Tests
Procedure
1. Disassemble the Generator until the brushes and
slip rings are exposed. Refer to Section 6.1 “Major
Disassembly.”
2. Inspect the brush wires and verify they are secured and
properly connected.
3. Inspect the brush assembly for excessive wear, or
damage.
4. Inspect the rotor slip rings. If their appearance is dull or
tarnished, polish with a fine grade abrasive material.

Do not use metallic grit to polish slip rings. This may
cause irreversible damage to the rotor.
5. Wire 0, located on the negative brush terminal, provides
an electrical connection to ground for the rotor and the
voltage regulator. To test this wire for an OPEN condition,
remove Wire 0 from the brush assembly.
6. For C1 Configuration A disconnect the bulkhead connector
C1 inside the control panel. For C1 Configuration B
disconnect the J5 connector from the controller and
isolate Wire 0 from the ground stud.
7. Set Volt-Ohm-Milliammeter (VOM) to measure resistance.
8. For C1 Configuration A c onnect one meter test lead to
Wire 0 at the brush assembly and connect the other meter
test lead to C1 Pin 6. For C1 Configuration B c onnect
one meter test lead to Wire 0 at the brush assembly
and connect the other meter test lead to the Wire 0
disconnected in Step 6.
•If the VOM indicated INFINITY, repair or replace Wire 0
between the negative slip ring and C1 Pin 6 (Configuration
A) or the ground stud (Configuration B).
•If the VOM indicated CONTINUITY, continue to Step 9.
9. Wire 4, located on the positive brush terminal, provides an
electrical connection for excitation current to flow between
the rotor and the voltage regulator. To test this wire for an
OPEN condition, remove Wire 0 from the brush assembly.
10. For C1 Configuration A connect one meter test lead to
Wire 4 at the brush assembly and connect the other
meter test lead C1 Pin 5. For C1 Configuration B connect
one meter test lead to Wire 4 a the brush assembly and
connect the other meter test lead to J5 Pin 13.
•If the VOM indicated INFINITY, repair or replace Wire 4
between the positive slip ring and C1 Pin 6 (Configuration A)
or J5 Pin 13 ( Configuration B).
•If the VOM indicated CONTINUITY, continue to Step 11.
11. Connect one meter test lead to Wire 4 at the brush
assembly and connect the other meter test lead to frame
ground.
•If the VOM indicated CONTINUITY, repair or replace Wire 4
between the positive slip ring and C1 Pin 6 (Configuration A)
or J5 Pin 13 ( Configuration B).
•If the VOM indicated INFINITY, continue to Step 12.
12. Connect one meter test lead to Wire 0 at the brush
assembly and connect the other meter test lead to a clean
frame ground.
•If the VOM indicated INFINITY , repair or replace Wire 0
between the positive slip ring and the control panel ground
connection.
•If the VOM indicated CONTINUITY, refer back to flow chart.
Results
1. Repair, replace, or reconnect wires as necessary.
2. Replace any damage slip rings or brush holder.
3. Clean and polish slip rings as required.
TEST 10 – TEST ROTOR ASSEMBLY
Discussion
A rotor having open windings will cause loss of excitation
current flow and as a result generator AC output voltage will
drop to “residual” voltage. A “shorted” rotor winding can result
in a low voltage condition.
Procedure
1. Remove the brush assembly from the slip rings to prevent
interaction.
2. Set a Volt-Ohm-Milliammeter (VOM) to measure
resistance.
3. Connect one meter test lead to the positive slip ring
(nearest the rotor bearing) and the common test lead to
the negative slip ring, measure and record the resistance.
4. Connect one meter test lead to the positive slip ring and
connect the other meter test lead to a clean frame ground,
measure and record the resistance.
Results
1. Compare the resistance measured in Step 3 with the
“Specifications”, replace rotor as required.
2. If the VOM indicated CONTINUITY in Step 4, replace the
rotor assembly.
TEST 11 – CHECK AC OUTPUT FREQUENCY
Discussion
The generator AC frequency is proportional to the operating
speed of the rotor. The 2-pole rotor will supply a 60 Hertz AC
frequency at 3600 RPM.

Generac Power Systems 16 kW NG Specifications

General

Brand	Generac Power Systems
Model	16 kW NG
Category	Portable Generator
Language	English