Westerbeke 5.0Kw BCDR Operator's Manual page 52

5.0KW BC GENERATOR TROUBLESHOOTING
This troubleshooting chart is designed to give insight into
problems which may be encountered with BT brushless
generators operating on compound transformer regulation.
Owing to the simplicity of the equipment and controls,
troubleshooting is relatively easy, once the relationship
between cause and effect is understood.
WESTERBEKE recommends that the troubleshooting and
repair of the generator be performed by a qualified technician
with a thorough knowledge of electricity and the safety
procedures necessary when dealing with high voltages.
Problem Probable Cause
Only a few basic tools are necessary for diagnosis and repair.
These are hand tools: an amp probe and a quality volt-ohm-
meter capable of reading less than one ohm due to the
precision required in reading component winding resistances.
Before·attempting any repairs, get a clear an explanation of
the problem as possible, preferably from an individual
witnessing the problem. In some cases, this may bring to
light a problem which is related to the method of operation
rather than equipment fault. Have basic repair parts available,
such as: diodes and a bridge rectifier, so that if the problem is
found in one of these easily replaceable parts, repairs can 1]e
made efficiently.
VerlflcationJRemedy
No AC Output at No load.
1. Main stator winding is open or shorted. 1. Excite unit with 12 VDC. Check the stator windings.
ReSidual voltage (4 - 6 Volts) at NIL.
1. Faulty capaCitor. 1. Perform capacitor check.
2. Faulty electrical connections.
2. Check all electrical connections, ensure they are clean and tight.
3. Engine speed is too slow. 3. Adjust engine speed to correct NIL hertz.
4. Faulty exciter winding. 4. Check winding resistance value.
Check winding residual voltage output..
High No Load voltage output. 1. Engine speed is too fast. 1. Adjust engine speed to correct no load hertz.
2. No load voltage tap at capacitor . 2. Change tap to lower number.
..
..
3. Wrong hertz tap. 3. Check to ensure correct hertz tap attached.
Correct No Load voltage, voltage drops 1. Faulty diode.
1. Isolate diodes and check for short.
to 60 - 80 volts when load applied.
2. Poor governor reaction.
2. Check engine speed under load.
Adjust or repair governor as needed.
3. Overload on generator. 3. Check the engine speed.
Monitor amperage draw with amprobe.
Correct No Load voltage, high voltage 1. Engine speed is too fast.
1. Check engine speed. Adjust or repair governor as needed.
Unstable voltage output. 1. Poor governor reaction. 1. Check the governor. Adjust or repair the governor as needed.
2. Loose electrical connections. 2. Check the security and cleanliness of the electrical connections.
Noisy Generator.
1. Rear support bearing faulty. 1. Inspect rear bearing.
2. Unbalanced load (1201240 wired).
2. Monitor the amperage draw from each leg using amprobe.
3. Generator rotor connection 3. Check rotor security.
to engine is loose.
Engines & Generators
47