Electricity + Control January 2017

EARTHING + LIGHTNING PROTECTION

basic prerequisite for optimal building protection is a universal

concept that takes all measures necessary to protect against

surge voltage into account. Whether a building is a small

single-family home or a vast industrial complex is more or less irrel-

evant. The array of lightning and surge voltage protectors, structured

in tiers, must be well-conceived and precisely implemented. While

the use of a type 1 lightning protector varies according to a number

of different environmental parameters, the use of type 2 and 3 surge

protection is necessary in all cases.

Industrial building

The implementation of a surge protection concept

demonstrates the advantages of the newSafe Energy

Control (SEC) product range. The components from

this series allow multi-level protection concepts for

commonly used installations to be easily imple-

mented. The example used describes the planning

process on the basis of a simplified building concept.

This scenario details the protection of an end appliance

– in this case, an automated production system – in an

industrial building. The machine and building’s power infeed is

supplied via a three-phase 230/ 400 V TN-S system. The various end

devices in this industrial building are supplied with power through

several sub-distributors. In addition, the building is equipped with an

external Lightning Protection System (LPS).

Main distributor

Because of the external LPS, a corresponding interior LPS is also

required. To meet this requirement, a type 1 lightning current arrester

must be installed right where the power line enters the building. Be-

Safe Energy Control

Simplifies Surge Protection

The Safe Energy Control (SEC) product range offers high performance

and a long service life for lightning and surge voltage protection.

Dipl.-Ing. (FH) Florian Lenzmeier, Phoenix Contact GmbH & Co

cause, in our example, there are already a PLC (Programmable Logic

Controller) and various telecommunications equipment near themain

distributor, the LT-SEC-T1+T2 lightning/surge voltage arrester combi-

nation has been selected here (see sidebar text 1). Since the main dis-

tributor is already protected by amain fuse (F1 = 315 gG), the lightning

arrester requires no additional back-up fuse in this case.Type 1 arresters

from the SEC range require no additional back-up fuse up to 315 A. In

applications with higher rated current, either an additional back-up fuse

or the FLT-SEC-Hybrid – a combination of a fully-enclosed spark gap

and an integrated surge-current resistant back-up fuse – can be used.

Sub-distributor

Because the nearest floor or sub-distributor is located far away from

the main distributor in this example, the use of a type 2 surge

voltage protector is required. The VAL SEC surge voltage

protector is a suitable choice. As with type 1 protectors

from the SEC range, this device can be used in ap-

plications that are protected up to 315 A without an

additional back-up fuse. Because the device is one

of the slimmest surge voltage protection devices on

the market, the installer saves bothmoney and space.

In our example, a three-phase TN-S network can be

protected over less than three horizontal pitches – or

less than 50 mm.

Protecting the end device

The type 3 surge voltage protector is installed right in front of the end

device to be protected – in this case, the production system control-

ler and robot arm. The PLT-SEC surge protector is being used. The

main advantages of this device are its convenient installation and

universal use. That is because type 3 products from the SEC range

are equally suitable for use in ac and dc applications. An additional

back-up fuse in single-branch configuration is unnecessary because

all PLT-SEC devices come with pre-installed, built-in back-up fuses.

Electricity+Control

January ‘17