KEB COMBIVERT F5-A, Руководство по применению, Страница: 413 / 552

Protective functions
© KEB, 2012-10 COMBIVERT F5-A, -E, -H Page 7.13 - 39
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7.13.11.2 Adjustment of the activation threshold
The DC link voltage threshold where the braking transistor becomes active can be adjusted with Pn.69 "GTR7
voltage".
The settings range is 300..1500V. This value is internally limited down in the inverter: the braking transistor
becomes active no earlier than ru.68 "DC link voltage rated value" * 1.0625.
The DC link voltage rated value is the DC link voltage measured at "Power on".
7.13.11.3 Activation conditions
In the factory settings, the braking transistor is only active if the modulation is also enabled.
The reason for it is that for "standard" asynchronous motors, the recovery of energy into the inverter also ends
with shutdown of the modulation.
When using synchronous machines in the field weakening range, or using sine filters at the inverter output,
recovery may continue despite the modulation being switched off.
In that case, Pn.65 should be changed.
Pn.65: Special functions
Bit Meaning Explanation
0
1: GTR7 function
for LS
GTR7 function also available in status "70: standstill (Modulation off)" (LS)
3
8: GTR7 release on
error
GTR7 function also available if the inverter is in an error state.
Exception: On opening of the hardware control release (terminal X2A.16) and
for an unpowered power circuit (status 13: power circuit not ready), the GTR7
is always switched off.
5
32: GTR7 function
for SW nop
The terminal ST causes an immediate hardware switch-off of the braking tran-
sistor. If the GTR7 function shall be available in status „0: no control release“
(nop) software-control release must be used (can be activated via di.36). The
GTR7 can then be activated for the status "no control release" with bit 5.
Exception: On opening the hardware control release (terminal X2A.16), the
GTR7 is always switched off.
In which cases the braking transistor remains active even if modulation is switched off depends of the specific
application.
7.13.11.4 Electrical work via GTR7
The electrical work that is converted via the GTR7 resistance is displayed with parameter ru.91. The correct
input of the resistance in Pn.82 is required therefor. On reaching the maximum value of 99999 kWh the counter
is limited to this value. The limitation is given by the operator display (5 digits).
Parameter ru. 91 is writable. It is set to its default value by new-initialization and writing on power on counter
(ru.40).
Pn.82 GTR7 resistance
range 0.000… 5000.000 Ohm (Default 0.000 Ohm)
ru.91 Energy over gtr 7
range 0… 99999 kWh (Default 0 kWh)