Tadiran Telecom Swift Inverter 9U Service Manual page 49

Tools required Multimeter, pressure gauge, megameter, module panel in normal
condition
for inspection
Supply voltage, compressor wire, reactor, system pressure, module
Frequent
problematic part panel, main external control panel, compressor
1. Is the order of compressor wires not correct, which makes the
compressor rotate reversely? Try exchanging the compressor wires on
U-V phase to see if the problem can be solved?
2. Check if the supply voltage is unstable and highly volatile, and test
if the system pressure is normal. High system pressure will cause
rotating problems to the compressor.
3. Is the module panel fixed to the radiator firmly? Will it cause pool
cooling? Is the internal and external heat exchanger dirty, which lead to
poor heat transfer and high system pressure?
4. If "module protection error" will be indicated immediately after
starting up, it is almost certain that it's substantial error, having nothing
to do with supply voltage and system pressure, it is suggested to
observe if there is any component destroyed by strike arc near the
module panel; use the multimeter to test if the resistances between any
two compressor wires are the same. The resistances between any two
compressor wires in normal condition are tiny resistances at ohm level
and are basically equal; then use the megameter to measure if the
resistance insulation of the three compressor wires against the earth
wire is good (normally at MΩ level), and check if the reactor wire is
Inspection
well connected or the reactor is destroyed.
procedure and
5. Test if the 15V and 5V (3.3V) power supply on the module panel is
key points
stable and exclude the module panel error caused by power supply of
the main external control panel.
6. Methods for judging whether the power module is damaged: use the
"diode position" of the multimeter to measure the features of P of the
module panel against U-V-W three phases respectively. Measure the
power module P-U, P-V and P-W, there is always infinite resistance at
one side and fixed on-state voltage at the other side (generally 0.5V);
measure the features between N-U, N-V and N-W in the same way, if
short circuit occurs during any measurement, then the module is
destroyed.
7. Replace with the module panel in normal condition for test. If the
test is normal after changing the module panel, then the original
module panel is destroyed.
8. After excluding problems of module, connecting wires, system and
power supply, distinguish by ear. If there is only electromagnetic sound
and the compressor does not work; or the sound of irregular running
appears after the compressor works for a while and then it shuts down
and indicates error; chances are that the compressor is blocked or
destroyed, consider replacing the compressor.
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