User Manual

15-9
Siemens Switzerland Ltd www.siemens.com/gamma 2019
Building Technologies Division
Technical Information and Application Examples
Technical Information
UL standard
GAMMA instabus Devices comply with UL standard
Broad spectrum
UL standards are used in North America, but also in several other
countries. The mark UL (Underwriters Laboratories) is allowed to print
on the product when the security check was successfully done accor-
ding to the UL guidelines. This is of particular importance to European
exporters of electrical switchgear equipment for machines who export
to the USA, as their products will only be accepted if they meet the re-
levant UL standards. UL 508A describes the design of control cabinets
and implementation of integral components with reference to other
pertinent UL standards where applicable. It therefore represents the
basic standard for all electrical systems used in North America. A wide
range of GAMMA instabus devices comply with UL standards and are
therefore suitable for implementation worldwide in both IEC/EN and UL
applications within the framework of their specified use.
Further links:
For general information about the UL standard: www.ul.com
Online database for UL products: www.ul.com/database
For information about ul certification: www.ul-certification.com
For information about GAMMA products: www.siemens.com/gamma
Worldwide application of EN/IEC or UL standards
IEC e.g.: EN, VDE, BS, NF
UL/CSA
I201_13559
Low-voltage systems in the USA
While a variety of different systems are used in the USA, three-phase systems with 240 V as well 480 V and 3- and 4-wire systems are the most
common, with 208 V and 600 V playing a considerably smaller role. Residential buildings are primarily fitted with 120 V to 240 V single-phase
systems. A frequency of 60 Hz is standard in North America.
Industry and commercial Residential
Three-phase, 4 wires Three-phase, 3 wires Single-phase, 3 wires
Three-phase wye, 4 wires Three-phase delta, 3 wires, grounded corner Single phase, 120 V/240 V, grounded midpoint
Caution:
The PE must not be used for electricity. There is
no PEN conductor => N = „Grounded Conduc-
tor“ (white or gray), separate wires must be
used for PE and N.
480 V Y/277 V
1)
240 V 240 V, phase conductor
600 V Y/347 V
1)
480 V 120 V to ground
240 V Y/131 V
1)
600 V
208 V Y/120 V
1)
1)
"Y" describes the „Solidly grounded circuit“. The „Y“ value specifies the voltage between the phases (e. g. 480 V), the value after the slash specifies the
voltage between the phase and the grounding (e.g. 277 V at 480 V voltage between the phases).
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