After-Repair Tests - Danfoss VLT FC Series Service Manual

Test Procedures
Incorrect signals indicate problems in the external control
wiring to the drive, configuration of the switches, or a
faulty control card.
The power for the analog inputs either comes from the
supply built into the drive, or from an external supply. If an
external supply is used, reference the common of the
supply to terminal 55.
Verify the control voltage supply
1. Connect the (-) negative meter lead to
terminal 55.
2. Connect the (+) positive meter lead to
terminal 50.
The correct reading is 9.2–11.2 V DC. If the supply voltage
is not present, perform the basic control card voltage test.
Verify that the analog input is configured for the type of
signal being sent to the drive. Parameter 16-61 Terminal 53
Switch Setting shows the configuration of terminal 53, and
parameter 16-63 Terminal 54 Switch Setting shows the
configuration of terminal 54. If the inputs are not
8 8
configured correctly, power down the drive and change
switches S201 and S202.
Check the individual inputs if configured for voltage
1. Connect the (-) negative meter lead to
terminal 55.
2. Connect the (+) positive meter lead to terminal
53 or terminal 54 and measure the DC voltage.
For each analog input, the measured DC voltage must
match the value shown in the display parameter. If the
display does not correspond with the measured input and
the switch is configured for voltage, the analog input on
the control card has failed. Replace the control card.
Check the individual inputs if configured for current
1. Connect the (-) negative meter lead to
terminal 55.
2. Connect the (+) positive meter lead to
terminal 53 or terminal 54 and measure the DC
voltage.
When configured for current, the current flows through a
200 Ω resistor to create a voltage drop. A 4 mA current
flow creates approximately a 0.8 V DC voltage reading. A
20 mA current flow creates approximately a 4.0 V DC
voltage reading. The display shows the mA value. If the
display does not correspond with the measured input, the
analog input on the control card has failed. Replace the
control card.
Incorrect reading
A negative voltage reading indicates a reversed polarity.
Reverse the wiring to the analog input.
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VLT FC Series, D1h–D8h, Da2/Db2/Da4/Db4, E1h–E4h, J8/J9

8.6 After-repair Tests

WARNING
DISCHARGE TIME
The drive contains DC-link capacitors, which can remain
charged even when the drive is not powered. High
voltage can be present even when the warning LED
indicator lights are off. Failure to wait the specified time
after power has been removed before performing service
or repair work can result in death or serious injury.
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Enclosure Size
D1h–D8h drives
J8–J9 drives
D9h–D10h enclosed drive systems
Da2/Da4/Db2/Db4 parallel drive systems 20 minutes
E1h–E4h drives
E5h–E6h enclosed drive systems
Table 8.16 Discharge Time
Danfoss A/S © 02/2019 All rights reserved.
Stop the motor.
Disconnect AC mains and remote DC-link power
supplies, including battery back-ups, UPS, and
DC-link connections to other drives.
Disconnect or lock the motor.
Disconnect any brake option.
Disconnect any regen/load share option.
Wait for the capacitors to discharge fully. The
minimum waiting time is specified in the
following discharge time table and is also
visible on the drive label.
Before performing any service or repair work,
use an appropriate voltage measuring device to
make sure that the capacitors are fully
discharged. For parallel drive modules, measure
DC-bus capacitor voltages before and after the
individual DC fuses.
Minimum waiting time
20 minutes
20 minutes
20 minutes
40 minutes
40 minutes
MG94A502