Installation Guide

Motor Control Solutions Combination Starter Construction Types

UL Combination Starter Types A through D

UL 508 Types A through D combination starters are traditional style starters that

use either a listed disconnect switch and fuses or a listed circuit breaker as the

disconnect means and short circuit protection. Each type uses a separate UL 508

listed motor controller and overload relay. These starters are evaluated by UL

under the same set of short circuit performance tests. Each type of combination

starters clears detected faults without causing a fire or posing an electrical shock

hazard to personnel. Each type is allowed to sustain damage that is contained

within enclosures and may require the repair or replacement of devices after

performing their protective function.

UL Combination Starter Type E

The concept of a self-protected combination starter was introduced from Europe

during the 1980’s. This concept unveiled an integrated device that performed all

the required functions of a combination starter.

The first self-protected combination starters were manual, but by the

mid-1980s, electromechanical self-protected combination starters were also on the

market. These starters cleared detected faults within their rating without sustaining

damage and could be put back into operation.

UL recognized this concept in 1990 and added the Type E self-protected category

for both manual and electromechanical combination starters. UL added a separate

set of short circuit and endurance performance tests to their 508 standard just for

the Type E self-protected category.

UL Combination Starter Type F

Many manufacturers and users started combining a manual UL 508 Type E self-

protected starter with a UL 508 contactor and called the combination “self-

protected.” This is not an accurate description since the combination was not

tested in accordance with the requirements of the UL 508 Type E standard as a

combination.

UL addressed this by recognizing a Type F category in 2002. This combination

starter consisted of the manual self-protected starter and contactor combination. It

is evaluated under the same short circuit tests as Types A through D, but it is not

considered self-protected.

Self-Protected Designation and Implications

A combination starter must pass certain performance tests specified by UL 508

before it can be designated as self-protected. The required test sequence for the

Type E self-protected combination starters is listed in UL 508, Table 77.4A. The test

sequence includes both high fault and interrupting ability short circuit (low fault)

detection tests, followed by an endurance test.

The tests required for Types A through D and Type F combination starters are

listed in UL 508 Table 77.4. This test sequence does not include the detection of

low fault short circuit tests followed by the endurance test. This is the difference

between the testing and performance of a Type E self-protected combination

starter and the starter types.