Yaskawa VS-616G5 Series Revision F Programming Manual - Manual (Page 119)

VS-616G5 Programming Manual 119
This parameter assists in protecting the IGBT from overheating of the transistor junction when the out-
put current is high and the output frequency is low. The settings are as follows:
This parameter allows the selection of normal or fast OL2 protection below 6 or 10 Hz. It is recom-
mended that this parameter be enabled at all times. In some instances fast OL2 protection (L8-19=1)
may not be desired, such as when operating in flux vector at zero speed. If L8-19 is set to 0 (disabled)
L8-17 must be set to 1,2, or 3.
Caution: When disabling OL2 protection, (L8-19=0) verify that the motor current will not go beyond
the current limit level when operating below 10 Hz. Or set the carrier frequency equal to or
less than 2 kHz.
L8-17 IGBT Protection at Low Speed Prtct@L-Spd A A A —
Setting Description
0 Conventional Method (No change in carrier), inverter relies on L8-19 protection (same as 1042
software).
1 Lower fc - When output current is greater than 100%, and output frequency is less than or equal to
10Hz, the carrier frequency is automatically decreased to the L8-18 setting (between 8 and 2 kHz
depending on model). The carrier will automatically return to the normal value after the load is
reduced.
(factory default)
2 Short term OL2 - OL occurs in 2 seconds when at low output frequencies (6Hz or less) and in hard
current limit.
3 I-Limit=150% - Current limit is 150% of inverter rated current. The IGBT junction temperature
should be below any critical level provided the output current is less than 150%.
<1110>
L8-19 OL2 Characteristics at Low speed
<1110>
OL2 Chara@L-Spd A A A A
Setting Description
0 Disabled -OL2 protection is disabled at low speed. This OL2
protection is the same at high speed and low speed. (factory
default).
1 Enabled - A current limiting function is performed at low
speed, the inverter OL2 protection responds quickly at 6 Hz or
less.
Section L: Protection Parameters
L8 Hardware Protection