Danfoss VLT 5000 Series Instruction Manual page 206

Before servicing the installation (adjusta-
ble frequency drive + motor), it must be
checked that the intermediate circuit volt-
age is below 60 V DC. This is done by
measuring terminals 88 and 89, load-
sharing.
NOTE
The power dissipation during quick dis-
charge does not form part of the power
monitoring function,
When sizing resistors, this fact should be
taken into consideration.
Mains failure/quick discharge with mains failure
inverse
The first column in the table shows Mains failure , which
is selected in parameter 407. If no function is selected,
the mains failure procedure will not be carried out. If
Controlled ramp-down [1] is selected, the frequency
converter will take the motor down to 0 Hz. If Enable
[1] has been selected in parameter 408, a quick dis-
charge of the intermediate circuit voltage will be car-
ried out after the motor has stopped.
Using a digital input, it is possible to activate mains
failure and/or quick discharge. This is done by select-
Mains failure par. Quick discharge par. 408
407
No function [0] Disable [0]
No function [0] Disable [0]
No function [0] Enable [1]
No function [0] Enable [1]
[1]-[4] Disable [0]
[1]-[4] Disable [0]
[1]-[4] Enable [1]
[1]-[4] Enable [1]
Function no. 1
Mains failure and quick discharge are not active.
Function no. 2
Mains failure and quick discharge are not active.
MG.51.C5.22 - VLT is a registered Danfoss trademark.
Parameter 408 = [1]
Quick discharge
activated
Check 24 Volts
external DC supply
24 Volts external
DC supply OK
Start
parameter 403.
Quick discharge
Discharge
Discharge completed
175ZA447.10
ing Mains failure inverse on one of the control terminals
(16, 17, 29, 32, 33). Mains failure inverse is active in the
logical '0' situation.
Mains failure inverse digital in-
put
Logical '0'
Logical '1'
Logical '0'
Logical '1'
Logical '0'
Logical '1'
Logical '0'
Logical '1'
Function no. 3
The digital input activates the quick discharge function,
regardless of the intermediate circuit voltage level and
regardless of whether the motor is running.
®
VLT 5000 Series
TRIP (RESET)
ALARM:33
No 24 Volts external
DC supply
Q.DISCHARGING FAILED
TRIP (RESET)
ALARM:33
Timeout
Q.DISCHARGING FAILED
POWER IS DISCHARGED
NOTE
The frequency converter can be com-
pletely damaged if the Quick-discharge
function is repeated, using the digital input
while mains voltage is on.
Function
1
2
3
4
5
6
7
8
203