5 20 60 Output frequency
Constant torque B_13 = 01
Reduced
torque
B_13 = 00

3–24

“B” Group: Fine Tuning Functions

Electronic Thermal Overload Alarm Setting

The thermal overload detection protects the inverter and motor from overheating due to an excessive load. It uses a current/inverse time curve to determine the trip point.

First, use B_13 to select the torque characteristic that matches your load. This allows the inverter to utilize the best thermal overload characteristic for your application.

Torque

100%

80%

60%

0

Hz

120

The torque developed in a motor is directly proportional to the current in the windings,

which is also proportional to the heat generated (and temperature, over time). Therefore, you must set the thermal overload threshold in terms of current (amperes) for parameter B_12. The range is 50% to 120% of the rated current for each inverter model. If the current exceeds the level you specify, the inverter will trip and log an event (error E05) in the history table. The inverter turns the motor output OFF when tripped.

 

 

 

“B” Function

Run

 

Defaults

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Func.

Name /

 

Description

Mode

–FE

–FU

 

–FR

Units

Configuring ParametersDrive

 

 

Edit

 

 

Code

SRW Display

(CE)

(UL)

 

(Jpn)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

B_12

Level of electronic

 

Set a level between 50% and

✘

Rated current for each

%

 

 

 

thermal setting

 

120% for the rated inverter

 

inverter model

 

 

 

 

 

 

current.

 

 

*See note

 

 

 

 

 

E-THM LVL 03.00A

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

B_13

Electronic thermal

 

Select from two curves, option

✘

01

01

 

00

—

 

 

 

characteristic

 

codes:

 

 

 

 

 

 

 

 

 

 

 

00 ...Reduced torque

 

 

 

 

 

 

 

 

 

E-THM CHAR

CRT

 

 

 

 

 

 

 

 

 

01 ...Constant torque

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

WARNING: When parameter B_12, level of electronic thermal setting, is set to device FLA rating (Full Load Ampere nameplate rating), the device provides solid state motor overload protection at 115% of device FLA or equivalent. Parameter B_12, level of electronic thermal setting, is a variable parameter.

NOTE: For inverter models 005NFE, 011NFE, and 030HFE, the thermal value is less than the rated amperes (is the same as models 004NFE, 007NFE, and 040HFE respec- tively). Therefore, be sure to set the electronic thermal overload according to the actual motor driven by the particular inverter.