Effective 8/13/99
Page 2
I.L. 70C1037H02
NOTE: The recommendations and information contained
herein are based on experience and judgement, but
should not be considered to be all inclusive or to cover
every application or circumstance which may arise.
If you have any questions or need further information or
instructions, please contact your local representative or
the Customer Support Center at 1-800-356-1234.
1.0 GENERAL DESCRIPTION OF DIGITRIP TRIP UNITS
The Digitrip Trip Units are breaker subsystems that
provide the protective functions of a circuit breaker. The
trip units are in removable housings, installed in the
breaker, and can be replaced or upgraded in the field by
the customer.
This instruction book specifically covers the application of
Digitrip Trip Units, as illustrated in Figure 1.1, installed in
Magnum and Magnum DS Breakers. Throughout this
Instructional Leaflet, the use of the term “Magnum
Breakers” refers to both the Magnum and Magnum DS
low-voltage, ac power circuit breakers.
The Magnum Digitrip line of trip units consists of the 220,
520, and 520M for UL standards and models 220, 520
i,
and 520M
i
for IEC standards. Throughout this Instruc-
tional Leaflet, the use of the term “DT20 family” refers to
the 220, 520, 520
i
, 520M, and 520M
i
units; the term “520
family” refers to only the 520, 520
i
, 520M, and 520M
i
units.
Figure 1.1 Digitrip 520M Trip Unit with Rating Plug
