Siemens S7-400 Components in figure A-7, Ser. No Components Description From fi Gure A-7

Assembling and Installing Systems

Components in figure A-7

The table A-6 explains consecutive numbers in the figure A-7:

Table A-6	Example of a Circuit Conforming to Lightning Protection Requirements
	(Legend to Figure A-7)
Ser. No.	Components	Description
from fi-
gure A-7
1	Lightning arrestor, depending on	High-voltage protection against direct
	the mains system, e.g. TN-S sy-	lightning strike and surge voltage as of
	stem:	transition 0 <--> 1
	1 piece DEHNbloc/3,
	order number: 900 110* and
	1 piece DEHNbloc/1,
	order number: 900 111*
2	surge arrestors,	High-voltage surge protection at transi-
	2 pieces DEHNguard 275;	tion 1 <--> 2
	order number: 900 600*
3	Surge arrestor,	Low-voltage surge protection for RS 485
	Blitzductor CT type MD/HF,	interfaces at transition 1 <--> 2
	order number: 919 506* and
	919 570*
4	Digital input modules:	Low-voltage surge protection, signal mo-
	FDK 2 D 60 V, order number:	dules I/O at transition 1 <--> 2
	919 993*
	Digital output modules:
	FDK 2 D 5 24 V, order number:
	919 991*
	Analog modules:
	MD 12 V Blitzductor CT,
	order number: 919 506 and
	919 541
5	Bus cable shielding mounting de-	Discharge of interference current
	vice with EMC spring clamp on
	the basic unit of Blitzductor CT;
	order No.: 919 508*
6	Cable for equipotential bonding	Standardization of reference potentials
	16 mm
7	Blitzductor CT, type B for building	High-voltage surge protection for RS 485
	transitions;	interfaces at transition 0 <--> 1
	order number: 919 506* and
	919 510*
* You can order these components directly at:		DEHN + SÖHNE
		GmbH + Co. KG
		Elektrotechnische Fabrik

Hans-Dehn-Str. 1

D-92318 Neumarkt

Automation System S7-400	Hardware and Installation	A-29
A5E00850741-01