Operating Instructions

Descriptions of Parameter Settings
Descriptions of Parameter Settings
179 | 443
Pr.
Explanation
Settings
Default
06-49
LvX auto-reset
0: Disable
1: Enable
0
06-53
Input phase loss detection action
(OrP)
0: Fault and ramp to stop
1: Fault and coast to stop
0
The drive executes the input phase loss protection according to Pr.06-53.
Pr.
Explanation
Settings
Default
06-55
Derating protection
0: Constant rated current and limit carrier frequency by load current and
temperature
1: Constant carrier frequency and limit load current by setting carrier
frequency
2: Constant rated current (same as setting 0), but close current limit
0
● Allowable maximum output frequency and the minimum carrier frequency limit in control mode:
For VF, SVC, VFPG modes:
When the maximum output frequency is 599 Hz, the minimum carrier frequency is 6 k.
● Setting 0:
When the operating point is greater than the derating curve (when the operating carrier frequency is greater
than the rated carrier frequency), the rated current is constant, and carrier frequency (Fc) output by the drive
decreases automatically according to the ambient temperature, overload output current and overload time. If
overloads are not frequent, and the concern is only about the carrier frequency operating with the rated current
for a long time, and changes to the carrier frequency due to short overload are acceptable, set to 0.
See Section 9-7 Derating for Ambient Temperature, Altitude and Carrier Frequency for the carrier frequency
derating level.
Take RT-005X-43N in normal load as an example: ambient temperature 50°C, UL open-type, and independent
installation. When the carrier frequency is set to 10 kHz, it corresponds to 55% of the rated output current. In
the same condition for ambient temperature 40°C, it corresponds to 75% of rated output current. When the
output current is higher than this value, it automatically decreases the carrier frequency according to the
ambient temperature, output current and overload time. At this time, the overload capacity of the drive is 150%
of the rated current.
● Setting 1:
When the operating point exceeds the derating curve 1, the carrier frequency is the setting value. Select this
mode if the change of carrier frequency and motor noise caused by ambient temperature and frequent overload
are not allowed. (See Pr.00-17.)
See Section 9-7 Derating for Ambient Temperature, Altitude and Carrier Frequency for the rated current
derating level. Take RT-005X-43N in normal load as an example. If you need to maintain the carrier frequency
at 10 kHz, decrease the rated current to 55%. The OL protection executes when the current is 120% * 55% =
66% for one minute; therefore, you must operate using the values within the derating curve to keep the carrier
frequency constant.
● Setting 2:
The protection method and action are the same as setting value 0, but it disables the current limit when output
current is the derating ratio ×120% (default value) in normal load and when the output current is the derating
ratio ×180% (default value) in heavy load. The advantage is that it provides a higher starting output current
when the carrier frequency setting is higher than the default. However, the carrier frequency derates easily
when it overloads.
Example: when Pr.06-55 = 0 or 1, over-current stall prevention level = Ratio * Pr.06-03. When Pr.06-55 = 2,
the over-current stall prevention level = Pr.06-03.
● Use this parameter with Pr.00-16 and Pr.00-17.