ABB Electrical SPAM150C Motor Protection Relay

Model Type: SPAM150C Electrical SPAM 150 C SPAM 150 C Motor Protection Relay

Brief Introduction

The SPAM150C Motor Protection Relay is a general purpose combination relay designed primarily for the protection of AC motors for a variety of applications.

It combines a large number of protection functions in one unit. The relay provides a complete set of protection against motor damage caused by various electrical faults.

The relay is also suitable for other equipment requiring thermal overload protection, such as cable or power transformer feeders.

Summary of Protection Functions

The relay thermal overload unit protects the motor against short- and long-term overloads. The maximum permissible continuous load depends on the setting value 1.

Normally this setting value is taken as the rated full load current (FLC) of the motor at an ambient temperature of 40°C. The motor can be overloaded for a short period of time if the motor is not loaded.

When the motor current increases to 1.05I under the above conditions, the thermal overload unit starts after a certain delay.

If the ambient temperature of the motor is below 40°C for a long period of time, the setting value I. can be set to .05...1.10 times the full load current (FLC) of the motor. 1.10 times.

The short-time overload phenomenon mainly occurs during the starting process of the motor. The motor is normally allowed to start twice under cold conditions and once under hot conditions.

One start is permitted under hot conditions, therefore, depending on the starting time of the motor, an integrating value t determining the characteristics of the thermal overload unit can be derived.

This value can be easily determined from the time/current graph in the hot state. t curve is selected from the starting current versus the corresponding starting time (with an appropriate margin).

The t-curve is selected from the starting current versus the corresponding starting time (with an appropriate margin). Using the same value of t, the total permissible starting time of the motor under cold conditions can be found from the cold curve.