6. Description of Parameters
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For example, application requires detect of Err11 when motor runs at 150% of rated motor
current for two minutes.
According to Figure 7-47, 150% (I) is in the range of 145% (I1) and 155% (I2). 145% corresponds
to overload protection time 6 minutes (T1) and 145% corresponds to overload protection time
4 minutes (T2). You can calculate overload protection time T corresponding to 150% from the
following formula:
T = T1 + (T2 - T1) x (I - I1) / (I2-I1) = 4 + (6 - 4) x (150% - 145%) / (155%-145%) = 5 minutes
Then calculate motor overload protection gain from the following formula: F9-01 = Desired
overload protection time / Corresponding overload protection time = 2 / 5 = 0.4.
The motor should be tted with overtemperature sensors (e.g PTC) and wired to a
protection relay. Such protection devices measure actual motor winding temperature
and is the ultimate protection.
Function Code Parameter Name Setting Range Default
F9-02
Motor overload pre-warning
coefcient
50% to 100% 80%
The AC drive has the motor overload pending function that reminds of motor overload in advance
through digital output function 6.
On the condition that F9-01 = 1.00 and F9-02 = 80%, when motor running current reaches 145%
of rated motor current and motor runs at this level for 80% x 6 = 4.8 minutes, DO terminal or fault
relay outputs the motor overload pending signal.
When F9-02 = 100%, the motor overload pending and the motor overload protection are
performed simultaneously.
6.6.2 Phase Loss Protection
Function Code Parameter Name Setting Range Default
F9-12
Input phase loss/pre-
charge relay protection
0: Disabled
1: Enabled
11
Units position: Input phase loss protection
Tens position: Pre-charge relay protection
This function parameter determines whether to perform input phase loss or pre-charge relay
protection.
Function Code Parameter Name Setting Range Default
F9-13
Output phase loss
protection
0: Disabled
1: Enabled
01
Units position: Output phase loss
protection
Tens position: Output phase loss
protection before running
Units position: It determines whether to perform output phase loss protection. If protection is
disabled but power output phase loss occurs, the AC drive does not detect the fault. At this
moment, actual current is larger than the current displayed on the operating panel.
Tens position: It takes about several seconds to detect output phase loss during running. In low-
frequency running application or application where risks exist in start with phase loss, set this
position to 1. In applications which have strict requirements on start time, set this position to 0.