Determining Overload Class for WEG Softstarters

The overload class setting in WEG softstarters represents the motor's thermal overload protection rating. It determines the level of motor protection against overheating.

Factors to Consider



Motor Nameplate Data

The motor nameplate typically lists the motor's overload class, usually expressed as a percentage (e.g., 1.0 = 100% overload protection).

Application Requirements

Consider the expected operating conditions and the likelihood of overloads.

WEG Softstarter Manual

Refer to the specific WEG softstarter manual for recommended overload class settings for different motor types and applications.

Generally, the following guidelines can be used



Class 10 (100%)

For motors with high starting currents or frequent overloads, such as conveyors and pumps.

Class 20 (125%)

For general-purpose applications where moderate overloads are expected, such as fans and compressors.

Class 30 (150%)

For applications where occasional overloads are possible, but motor protection is still required.

In your case

Since the motor is a 250hp motor, it's likely to have a relatively high starting current. The default setting of Class 30 may be excessive protection, allowing for 50% above the motor's rated current.* Class 20 (125%) provides a reasonable balance between motor protection and allowing for some transient overloads.Therefore, using

Class 20 seems appropriate in this situation.

Note: Always consult the motor and softstarter manuals for specific recommendations and verification of the selected overload class setting. Flag for review