ABB ACS 800 Series, Firmware Manual

Page: 78 / 340

Program features
78
Preprogrammed faults
Overcurrent
The Overcurrent trip limit is 3.5 * I
hd
(nominal motor current for heavy duty use).
There are several sources of the overcurrent trip:
• Software trip (time level 100 ms, level = 97% of measurement scale)
• Hardware level trip (97% of measurement scale for 35 ms)
• Hardware derivative trip (12.5% of measurement scale for 75 ms)
• Hardware level trip in parallel connected units by PBU logic (94% of
measurement scale for 75 ms)
A fault “ OVERCURRENT ” is given during overcurrent condition.The current
measurement is calibrated automatically during the start procedure.
DC overvoltage
The DC overvoltage trip limit is 1.3 * 1.35 * U
1max
, where U
1max
is the maximum
value of the mains voltage range. For 400 V units, U
1max
is 415 V. For 500 V units,
U
1max
is 500 V. For 690 V units, U
1max
is 690 V.
The actual voltage in the intermediate circuit corresponding to the mains voltage trip
level is 728 V DC for 400 V units, 877 V DC for 500 V units, and 1210 V DC for 690 V
units. See the following
Figure: DC voltage control and trip limits.
DC undervoltage
The DC undervoltage trip limit is 0.6 *1.35 * U
1min
, where U
1min
is the minimum
value of the mains voltage range. For 400 V and 500 V units, U
1min
is 380 V. For 690
V units, U
1min
is 525 V.
The actual voltage in the intermediate circuit corresponding to the mains voltage trip
level is 307 V DC for 400 V and 500 V units, and 425 V DC for 690 V units. See the
following
Figure: DC voltage control and trip limits.