Specifications

Type SSM Specication Guide

4 Low Voltage Products & Systems

1SXU132173M0201 [AC 1007.2] - 2/02 ABB Inc. • 888-385-1221 • www.abb.com/lowvoltage

1.0 Introduction

This specication describes the performance, functional specications and fabrication details for a digital reduced

voltage, stepless, solid state medium voltage motor starter that shall provide a selectable voltage ramp, current limit or

current ramp (all standard) method of soft starting 3-phase AC induction motors.

A) Each motor starter(s) shall be complete self-contained Class E-2 Combination Starters and house the fused

disconnect switch, in-line isolation contactor, solid-state controller, motor overload protection and bypass

contactor.

2.0 Codes and Standards

A) Unit(s) must be manufactured to the codes listed below:

ANSI American National Standards Institute

IEEE Institute of Electrical and Electronic Engineers

UL Underwriters Laboratories Inc.

NEC National Electrical Code

NEMA National Electrical Manufacturers Association

OSHA Occupational Safety and Health Act

B) Unit(s) must be approved and/or certied by, and carry the label(s) of Underwriters Laboratories (UL). Units

shall be UL / cUL 347 listed as a complete assembly, including all necessary sub assemblies and components

in the same package.

3.0 Product Features

Solid state reduced voltage motor starters shall be ABB’s SSM Series (sized as indicated), or pre-approved equal modied

to meet the requirements of this specication. The starter shall be complete with the following standard features and

adjustments.

A) Motor and Load Protection shall be integral to the starter assembly. Motor protection shall be based upon

modeling of the thermal characteristics of the motor as programmed by the user and measured by the starter.

All current referenced protection features shall be calculated from the motor nameplate FLA, and automatically

adjusted for the Service Factor, NEMA Design, Insulation Class, Line Voltage and Line Frequency as entered

by the user. All time based protection features shall be based on a Real Time Clock, remaining active through

any power loss. Starter shall provide the following functions:

1) Thermal Overload shall be provided by the on-board microprocessor control. Basic protection shall be

inverse time-current trip curves as dened by NEMA trip curve Classes. The trip curve classes shall be

programmable from between Class 5 and Class 30 and the starter shall be UL listed to provide each

individual class. As the most important protection feature of a starter, the overload protection shall be

based on a Dynamic Thermal Register retained in memory and provide the following features:

(a) Retentive Thermal Memory shall be used to ensure that the Dynamic Thermal Register does not

loose track of motor temperature after the power is lost or shut down. Upon reapplication of power, the

microprocessor shall be automatically updated as to the motor temperature and adjusted for real time

cooling while the power is off.

(b) Dynamic Reset Capacity shall retain a snapshot of the thermal capacity necessary to restart the

motor. The starter shall determine these requirements by recording and averaging the previous 3

successful start-ups. After an overload trip has occurred, the protection shall prevent resetting until

enough cooling time has passed and sufcient motor thermal capacity is available.

setup, the Dynamic Thermal Register shall be biased according to the following input information when

available: Cold Stall Time, Hot Stall Time, Stopped Cool Down Time, Running Cool Down Time, and all

of the real time information from the RTD Option if ordered.