Owner manual
120
4 Checking the power stage
The measurements described below are to be carried out only by
skilled specialists. Use a digital voltmeter. The measuring values
indicate the nominal value. If they are different, there is a defective.
4.1 Checking the mains rectifier
Disconnect inverter from the mains and wait until the DC bus has
discharged (approx. 3 minutes). You can measure directly at the
power terminals.
Measurement Measuring point Measuring value
Diodes in forward
direction
L1 → +UG
L2 → +UG
L3 → +UG
-UG → L1
-UG → L2
-UG → L3
≈ 0.4V
≈ 0.4V
≈ 0.4V
≈ 0.4V
≈ 0.4V
≈ 0.4V
Diodes in reverse
direction
+UG → L1
+UG → L2
+UG → L3
L1 → -UG
L2 → -UG
L3 → -UG
high-resistance (OL)
high-resistance (OL)
high-resistance (OL)
high-resistance (OL)
high-resistance (OL)
high-resistance (OL)
4.2 Checking the power stage
Disconnect inverter from the mains and wait until the DC bus has
discharged (approx. 3 minutes).
You can measure directly at the power terminals.
Measurement Measuring point Measuring value
Inverter diode
in forward direction
U → +UG
V → +UG
W → +UG
≈ 0.4V
≈ 0.4V
≈ 0.4V
Diodes in reverse
direction
UG → U
UG → V
UG → W
high-resistance
high-resistance
high-resistance
Inverter diode in forward
direction
-UG → U
-UG → V
-UG → W
≈ 0.4V
≈ 0.4V
≈ 0.4V
Inverter diode
in reverse direction
U → -UG
V → -UG
W → -UG
high-resistance
high-resistance
high-resistance
4.3 Checking the voltage supply on the control
board 8602MP
Inhibit controller
Remarks Measuring point Measuring value
+Vcc 15 Term. 20 →Term. 40 +14.25 V...+15.75 V
+Vref 10 V Term. 9 →Term. 40 +9.79 V...+10.21 V
-Vref 10 V Kl. 10 →Term. 40 -9.79 V... -10.21 V