Introduction and Safety
Introduction
The DHR family of vacuum circuit breakers is designed to
meet all the applicable ANSI, NEMA and IEEE standards.
Successful application and operation of this equipment de-
pends as much upon proper installation and maintenance
by the user as it does upon the careful design and fabrica-
tion by Siemens.
The purpose of this Instruction Manual is to assist the user
in developing safe and efficient procedures for the instal-
lation, maintenance and use of the equipment.
Contact the nearest Siemens representative if any addi-
tional information is desired.
Qualified Person
For the purpose of this manual a Qualified Person is one
who is familiar with the installation, construction or op-
eration of the equipment and the hazards involved. In ad-
dition, this person has the following qualifications:
• Training and authorization to energize, de-energize,
clear, ground and tag circuits and equipment in accor-
dance with established safety practices.
• Training in the proper care and use of protective equip-
ment such as rubber gloves, hard hat, safety glasses,
face shields, flash clothing, etc., in accordance with es-
tablished safety procedures.
• Training in rendering first aid.
Signal Words
The signal words “Danger”, “Warning” and “Caution”
used in this manual indicate the degree of hazard that may
be encountered by the user. These words are defined as:
Danger - Indicates an imminently hazardous situation
which, if not avoided, will result in death or serious in-
jury.
Warning - Indicates a potentially hazardous situation
which, if not avoided, could result in death or serious
injury.
Caution - indicates a potentially hazardous situation
which, if not avoided, may result in minor or moderate
injury.
Dangerous Procedures
In addition to other procedures described in this manual
as dangerous, user personnel must adhere to the follow-
ing:
1. Always work on de-energized equipment. Always de-
energize a breaker, and remove it from the switchgear
before performing any tests, maintenance or repair.
2. Always perform maintenance on the breaker after the
spring-charged mechanisms are discharged.
3. Always let an interlock device or safety mechanism per-
form its function without forcing or defeating the de-
vice.
Field Service Operation
Siemens can provide competent, well-trained Field Ser-
vice Representatives to provide technical guidance and ad-
visory assistance for the installation, overhaul, repair and
maintenance of Siemens equipment, processes and sys-
tems. Contact regional service centers, sales offices or
the factory for details, or telephone Siemens Field Service
at 1-800-241-4453.
Hazardous voltages and high-speed
moving parts.
Will cause death, serious injury or property
damage.
Only qualified persons thoroughly familiar
with the equipment, instruction manuals and
drawings should install, operate and/or main-
tain this equipment.
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