Trane TR170 - Rectifier Circuit Test; Inverter Section Tests

6.3.2 Rectier Circuit Test
Pay close attention to the polarity of the meter leads to
ensure the
identication
of any faulty component, in case
an incorrect reading appears.
Described next is the procedure to conduct the static test
on the
rectier.
NOTICE
In H6 units the +/-UDC terminals are not readily
accessible. Find terminals K601 (+) and K611 (-) between
the DC capacitors.
In H7-H8 units the +/-UDC terminals are directly
accessible on MK900 on the power card.
In I7-I8 units the +/-UDC terminals are accessible on
MK900 on the power card or on MK3 on the current
sensor board.
For further details, see chapter 6.3.5 Location of UDC
Terminals before measuring).
Before starting tests, ensure that meter is set to diode
scale.
Rectier test part I
1. Connect the positive (+) terminal of the
multimeter lead to the positive (+) DC Bus.
2. Connect the negative (-) terminal of the
multimeter lead to the input terminal L1, L2, L3
in turn. The multimeter indicates Innity.
Rectier test part II
3. Reverse the meter leads by connecting the
negative (-) terminal of the multimeter lead to
the positive (+) DC Bus.
4. Connect the positive (+) terminal of the
multimeter lead to the input terminal L1, L2, L3
in turn. The multimeter indicates Diode drop.
Rectier test part III
5. Connect the positive (+) terminal of the
multimeter lead to the negative (-) DC Bus.
6. Connect the negative (-) terminal of the
multimeter lead to the input terminal L1, L2, L3
in turn. The multimeter indicates a diode drop.
Rectier test part IV
7. Reverse the meter leads by connecting the
negative (-) terminal of the multimeter lead to
the negative (-) DC Bus.
8. Connect the positive (+) terminal of the
multimeter lead to the input terminal L1, L2, L3
in turn. The multimeter indicates Innity.
6.3.3 Inverter Section Tests
The inverter section is primarily made up of the IGBTs used
for switching the DC bus voltage to create the output to
the motor. The frequency converter also has clamping
capacitors between +UDC and -UDC on the IGBT.
CAUTION
Disconnect motor cables when testing inverter section.
With leads connected, a short circuit in one phase reads
in all phases, making isolation
dicult.
Before starting tests, ensure that meter is set to diode
scale.
Inverter test part I
1. Connect the positive (+) meter lead to the
positive (+) DC bus terminal.
2. Connect the negative (-) meter lead to terminals
U, V, and W in sequence.
Each reading must show innity.
Inverter test part II
1. Reverse the meter leads by connecting the
negative (-) meter lead to the positive (+) DC bus
terminal.
2. Connect the positive (+) meter lead to U, V, and
W in sequence. Each reading should show a
diode drop.
Inverter test part III
1. Connect the positive (+) meter lead to the
negative (-) DC bus terminal.
2. Connect the negative (-) meter lead to terminals
U, V, and W in sequence. Each reading should
show a diode drop.
Inverter test part IV
1. Reverse the meter leads by connecting the
negative (-) meter lead to the negative (-) DC bus
terminal.
2. Connect the positive (+) meter lead to U, V, and
W in sequence.
Each reading should show innity.
Test Procedures
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