Weidmuller PU User Manual

Installation instructions for PU-Overvoltage in Mains Control.

This equipment may only be installed by fully qualified personnel. Please note: the local installation regulations specific to the country of use must be observed.

1. Application

The PU-C overvoltage serves for the protection of low voltage consumer’s installations and electronic devices against surges resulting from atmospheric discharges (lightning) or switching operations. The PU-C meets the requirements of IEC 61643-1 01/02 Class II, VDE 0675, part 6, class C 11/89, draft and DIN VDE 0675. Part 6, A2, 10/96 and ÖVE SN 60 part 4 and part 1 and the Ö Norm 8001. Highly efficient metal-oxide varistors are used for voltage limiting components. For the PU 3+1C we use a spark gap between L-PE or PE-N.

2. Notes on installation

2.1 Site of installation The PU-C

The PU-C must be installed in the meter cubicle or distributing cabinet in such a way that the terminal room is protected against unauthorised access. The overvoltage protection must be installed by trained service personnel. The regulations covering the construction of a installation with overvoltage protective equipment is described in VDE V 0100 part 534; 4/99: Selection and construction of operating equipment. This norm (in preparation) is in conjunction with the following norms.

1 IEC 60364-4-43 “Protection from overvoltage resulting from atmospheric conditions and resulting

from switching activity.“ 2 IEC 61024-1 “Protection of buildings against lightning strikes“. 3 IEC 61312-1 “Protection against electromagnetic lightning impulse“.

2.2 Electrical connection The PU-C overvoltage protection must be connected with short lines between the (outer) supply conductor (L1, L2, L3) and the neutral conductor (N) and the earth (PE) of the consumer’s installation. The parallel routing of non-protected lines and protected lines must be avoided. For connection examples, see figures 1 and 2.

2.2.1 Connection to (outer) supply conductor and neutral conductor. As a rule, the same conductor cross-section is selected for the connecting lines to the PU arrester as for the (outer) supply conductor (L1, L2, L3) and the neutral conductor (N). In the event of a reduction of the cross-section, a protective device (e.g. service fuse) must be provided for short-circuit protection of the connecting lines. The arrester terminals must not be used as tee-off terminals. The PU-C back-up fuse can be selected up to a maximum of 125 A. Series connected residual-current devices (RCD) must be surge proof.

Notes: Use a 3-pole PU-C in a TN-C-S network, (see picture 1/ if the PEN line is used separately as PE and N, then select a 4-pole PU 4 C or the PU 3+1 C). According to DIN VDE 0100-534/A1 10/96, it is possible in a TT network to install a 4-pole PU-C protector, together with an arrester disconnector. The module PU 3+1C (old name PU 4 C TT ) catalogue number 841637, offers the best installation prerequisites if a potential transfer is to be avoided without the use of an arrester disconnector. The PU 3 C for 385 V is to be installed in IT networks with 230 V line-to-line voltage.

2.2.2 Connection to earth The arrester’s earth conductor must be connected by the shortest possible route (≤ 0,5m) to the earth terminal of the consumer’s installation. Longer connection lines reduce the efficiency of the overvoltage protector. Parallel routing with other electrical lines must be avoided. The earthed equipotential bonding strip is available for connection with the equipotential bonding of electrical consumer’s installations (see figures 1 and 2).

° It must always be ensured that the arrester earth is connected with the consumers installation. ° For TN systems, the PEN conductor and the earth conductor of the arrester must be interconnected. ° The PEN conductor of the electricity supply company must not be used as an earth electrode. ° Where the PE rail or PEN rail of a distribution board is used as an earth terminal, these must be

connected via a separated earth conductor to the earth electrode of the consumer’s installation.

The cross-section of the arrester earth conductor is determined, as with the main equipotential bonding conductors, according to table 1. The conductor must have 0,5 times the cross-section of the main

protective conductor, the upper limit is fixed at 25 mm2 Cu. A lower limit of 10 mm2 Cu is required. Cross section mm

Main protective conductor

- from the power source or

≤ 16 25 ≤ 35

- house service box or main distribution board outgoing protective conductor. Supply conductor ≤ 35 50 ≥ 70 Earth conductor of arrester 10 16 25 Table 1

3. Functional check PU overvoltage arresters must be subjected to a visual inspection, especially during thunderstorms. If the colour of the inspection window turns red, the arrester must be replaced by trained service personal.

3.1 Maintenance If the charge eliminator shows a red window as in 3., it must be replaced with a new one by trained service personal. The individual charge eliminators are pluggable and encoded according to their voltage. The varistor arrester must be removed when measuring the insulation resistance according to DIN VDE 0100 part 610. To remove, pull on the upper parts of the varistor. The charge eliminator compatible with the rated voltage of the plant must be re-installed.

Technical Data: PU xC PU xC PU xC PU xC PU xC PU 3+1 C PU 3+1 C

Max. Voltage V~ U

280 385 75 130 550 280 385

Rated diversion current i

20 kA 20 kA 15 kA 20 kA 20 kA 20 kA 20 kA

of top part Max. test current per Unit 1-way block i

2-way block i 3-way block i 4-way block i

Operating temperature range. - 40 °C to + 80

Conductor size 16- 25 mm 10 - 25 mm

40 kA 40 kA 15 kA 40 kA 40 kA 40 kA 40 kA

smax

70 kA 70 kA 40 kA 70 kA 70 kA

smax

100 kA 100 kA 100 kA 100 kA 100 kA

smax

100 kA 100 kA 100 kA 100 kA 100 kA 100 kA 100 kA

smax

(stranded wire) 6- 10 mm2 (solid wire)

(flexible ) Assembly Snap-on mounting on 35 mm top-hat rails according to DIN 43 880 A1. draft 6.81 Colour. Light grey, RAL 7035 orange orange

Material. Polyamide 6.6 Protection IEC 529 : IP 20

Dimensions 1-way block complete width 18 mm 2-way block complete width 36 mm 3-way block complete width 54 mm 4-way block complete. width 72 mm

Depth. 55.0 mm

• For DC-Applications please contact the manufacturer.

4. Connection of remote signalling unit

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