Short-Circuit Protection; Protecting Explosion-Protected Motors; Application Environment - Siemens SIRIUS 3RT Series System Manual

SIRIUS 3RU2/3RB3 overload relays
5.5 Configuration
5.5.2

Short-circuit protection

Either fuses (fused design) or motor starter protectors/circuit breakers (acc. to UL) (fuseless
design) must be used for short-circuit protection. The types of coordination must also be
considered when selecting load feeders from the tables.
References
More information
About the assignments of corresponding short-
circuit protective devices to overload relays with
contactor
5.5.3

Protecting explosion-protected motors

SIRIUS components meet a wide range of requirements for operation in hazardous areas
(ATEX explosion protection). An up-to-date type overview of approved devices appears in
the Siemens Low Voltage LV1 Catalog. More information and certificates for download are
available on the Internet (http://www.siemens.com/automation/service&support).
5.5.4

Application environment

The following information must be taken into account when planning applications involving
overload relays.
Installation altitude
The overload relays are approved for installation altitudes up to 2,000 m. The reduced air
density at altitudes higher than 2,000 meters affects the overload relays' electrical
characteristics. The reduction factors which have to be taken into account when using
overload relays at altitudes higher than 2,000 m can be obtained on request from our
Technical Assistance on the Internet (http://www.siemens.com/automation/service&support).
Operating conditions and resistance to extreme climates
The overload relays are climate-proof.
The overload relays are not sensitive to external influences such as shocks, corrosive
ambient conditions, ageing, and temperature fluctuations.
506
Can be found in the chapter titled
Technical data (Page 536) and in the
configuration guide titled "Configuring SIRIUS
Innovations - Selection data for load feeders in
fuseless and fused designs" (order no.:
3ZX1012-0RA21-1AC0)
System Manual, 01/2011, A8E56203870002-03
SIRIUS Innovations