At very low speeds (6 Hz and below) and very high current levels it can be possible to damage output transistors. Therefore the default setting of L8-15

is set to shorten the time before an OL2 fault will occur when operating at low speed with a relatively heavy load (L8-15 = "1: Enabled").

L8-18: Software CLA Selection

The Software CLA (software current limit level) is a drive protection function that will limit the drive's output current. The drive limits the output current

by reducing the output frequency whenever the current exceeds 110% of the drive rated current. If the current level drops below the Software CLA level,

then normal operation will continue.

If the software current limit is disabled (L8-18 = "0: Disabled"), the drive may trip on an OC fault if the load is prohibitively large or the acceleration is

too short. For proper drive protection and operation leave the Software CLA function enabled.

L8-19: Frequency Reduction Rate during OH Pre-Alarm

Specifies how much to derate the frequency reference when L8-03 is set to 4 and an OH prealarm is output.

L8-29: Current Unbalance Detection (LF2)

This function is available only when using PM Open Loop Vector.

Issues a stop command when the output current becomes unbalanced as a result of a damaged photocoupler or output phase loss. Set to 0 to disable this

function.

L8-35: Side-by-Side Installation Selection

Sets the type of installation. Default setting is for a standard type of set up. For a fully enclosed motor compliant with NEMA type 1 specifications, set

this parameter to "2". Set to "1" when taking advantage of Yaskawa's Side-by-Side installation.

L8-38: Carrier Frequency Reduction

Specifies the degree of reduction for the carrier frequency at low speeds for IGBT protection. There is no carrier frequency reduction when L8-38 is set

to 0. Set to "1" to derate the carrier frequency when operating at less than 6 Hz and during overload.

To always have a derated carrier frequency, set L8-38 to 2.

L8-40: Low Carrier Frequency Time

Sets the amount of time the drive will operate with a reduced carrier frequency. The carrier frequency derating function during run is disabled when this

parameter is set to 0.00 s.

L8-41: Current Alarm Selection

Allows or restricts an alarm from being triggered when the relative output current rises above 150%. Disabled when set to 0 (no output).

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YASKAWA ELECTRIC SIEP C710606 18A YASKAWA AC Drive – V1000 Technical Manual (Preliminary)

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