Danfoss Turbocor VTT Series - Figure 115 - PWM Connector - 6 Pin; Figure 116 - PWM Test Points

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M-SV-VT-001-EN Rev. A
Compressor Components
Figure 115 - PWM Connector
- 6 Pin
9. The measured voltage drop should be 0.33-0.46 VDC.
Figure 116 - PWM Test Points
Pin 1
TP 2: HV-
TP 3: 17VDC
TP 1: HV+
Diode Test
1. Isolate the Compressor power as described in the “Electrical Isolation of the Compressor/VFD”
section of this manual.
2. Disconnect the PWM Bearing Power Cables from the Compressor bearing feed throughs.
3. Unplug the 250V DC input to the PWM.
4. Using a Multimeter, set to measure Diode, place the positive(+) test lead on the HV- test point of
the PWM and negative(-) lead in the first pin hole of the rear PWM Bearing Power Cable.
5. The measured voltage drop should be 0.33-0.46 VDC.
6. Repeat in a clockwise rotation for all the outer pin holes of the rear Bearing Power Cable and the
4 pins of the front Bearing Power Cable (The center pin of the rear Bearing Power Cable does not
have a test value.).
7. Place the negative (-) test lead on the HV+ test point of the PWM and the positive(+) lead in the
first pin hole of the PWM Bearing Power Cable.
8. Repeat in a clockwise rotation for all the outer pin holes of the rear Bearing Power Cable and the
4 pins of the front Bearing Power Cable. (The center pin of the rear Bearing Power Cable does
not have a test value.)