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User Manual for INDU-ELECTRIC Power Distribution Boxes

Field of application for INDU-ELECTRIC Power Distribution Boxes

INDU-ELECTRIC mobile Power Distribution Boxes have been designed specially for use on construction sites, on stage and in the TV, film, and entertainment industries. INDU-ELECTRIC Power Distribution Boxes above 125 A must be connected and operated only by qualified electricians or appropriately instructed persons.
They are extremely reliable, even under harsh operating conditions, such as at extreme heat, heavy rain and prolonged full load.
The enclosures are made from THERMOLENE®. THERMOLENE® enclosures fulfil the requirements for the highest specified impact protection class IK10 according to EN 62262 (impact energy of 5 kg at a drop from 400 mm height). The low thermal resistance of THERMOLENE® ensures optimum heat dissipation (see section “Ambient temperature”). Due to the excellent heat dissipation of THERMOLENE®, the surface of the Power Distribution Boxes may reach a temperature above 40 °C during continuous use. This does not impair its reliability or safety.
The boxes are designed and manufactured in conformance with the Low Voltage Directive. The normative documents are:

DIN EN 61439-1 

DIN EN 61439-4

Further applicable specifications are the provisions of the employers’ liability insurance association:

DGUV-V3 Electrical sy stems and apparatus

BGI / GUV I-600 Selection and operation of mobile electrical apparatus according to field of application

Inspection before each use

Before taking the equipment into operation, perform a visual inspection. Any existing RCDs and RCBOs must be tested for correct functioning by pressing the test button before each use or hire. If an RCD or RCBO does not trip, it is not ready for use and must be immediately replaced or checked by a qualified electrician.
During the visual inspection, also check for damage to the protective covers of SCPDs, RCDs, RCBOs, the plug-in devices, the power cable incl. anti-kink sleeve and the enclosure.
In your own interest, replace any defective components immediately. Missing covers on the sockets, for example, can cause corrosion of the contacts. Corrosion and soiling of the contacts can lead to a considerable increase in contact resistance. Consequently, the contacts can become very hot and eventually cause the socket and plug to melt and fuse. Defective components must be replaced with identical parts according to standard EN 61439-1 (Low-voltage switchgear and controlgear assemblies – General rules). Repair work must then be carried out by electricians or under supervision and instruction of an electrician. In accordance with the regulation DGUV-V3 of the employers’ liability insurance association, each Power Distribution Box must be checked for electrical safety after every repair and before each hire.
Before commissioning after a longer storage period, the tripping times of the Power Distribution Boxes’ RCDs and RCBOs must be checked for compliance with the disconnection times using a suitable test device (suitable measuring devices can be found on the Internet, for example at
Tests must be carried out at specified intervals, but at least every six months. The test intervals should be specified so that any likely faults can be identified on time.
Observe the technical rules for operational safety TRBS 1201 and DIN VDE 0701-0702 2008-06 (repeat testing of electrical equipment).
In the case of frequent transport with ongoing vibration, the screw connections should be checked every three months. The repeat checks must be carried out by a qualified electrician.
Also refer to the information provided by the employers’ liability insurance association DGUV 203-049, DGUV 203-070 and DGUV 203-071.

Ambient temperature, thermal load and load factor

The Power Distribution Boxes are designed for operation under continuous load at an ambient temperature of 30 °C. Depending on the Power Distribution Boxes’ design, protection class and equipment level, its internal temperature may be significantly higher.
Due to the Power Distribution Boxes’ internal temperature, an outside temperature of 30 °C results in an average load factor of 0.75 per circuit.
The following rated currents result for the individual socket circuits under thermally unfavourable operating conditions (ambient temperature ≥35°C, MCB/RCD in series and with closed protective flap over the fuses):

Normal current SCPD trigger current
16A 10.80 A
32A 21.60 A
63A 42.50 A
125A 84.37 A

The ambient temperature limit of our Power Distribution Boxes is 45 °C at a rated load factor of 0.60.
Please contact us if you intend to use your Power Distribution Box at higher temperatures.

Usage location – weather resistance

Observe the protection classes on the nameplate. Power Distribution Boxes with a protection class of less than IP44 must be used only in dry conditions.
Power Distribution Boxes should not be installed with the socket side facing upwards.
If the nameplate does not indicate a degree of protection lower than IP44, INDU-ELECTRIC Power Distribution Boxes can be used outdoors. Please note that the Power Distribution Boxes must not be placed in water puddles deeper
than 20 mm unless they have been designed for a greater immersion depth.
To prevent the inner heating up further through sunlight, the Power Distribution Boxes should, where possible be placed in a shady location. Do not place the Power Distribution Boxes with the fuse side directly against a wall, as this impairs heat dissipation from the built-in short-circuit protective devices (SCPD).
For Power Distribution Boxes mounted in flight cases, the same limitations regarding their usage location apply. Note, however, that the flight case is made of wood and may swell when exposed to moisture.
Our Power Distribution Boxes are designed for pollution degree 3 (industrial environment) as well as for an EMC environment B (public low-voltage networks).
The insulation resistance must be measured between the active conductors and the protective conductor connected to earth.
If electronic equipment such as phase displays, LED indicators, measuring devices or electronic RCBOs are installed in the Power Distribution Boxes, these could be damaged or falsify the voltage reading at voltages above 500V. They must therefore be disconnected or, if applicable, the series-connected pico fuse removed.
According to VDE 100 Part 600 (Erection of low-voltage systems – Part 6: Tests according to IEC 60364-6:2016 Section 61.3.3), the active conductors may be electrically connected to each other and then tested against PE. In this case, the electronic devices do not have to be disconnected.
Insulation resistance measurements are meaningful for the total circuit only when all switching elements in the circuit are closed.


Transient overvoltage can be the reason for malfunction of electronic components, such as measuring devices and electronic RCDs.
Transient overvoltage can be caused by:
• Electrostatic discharge (more information:
• Switching operations in the power grid (surge, pulse rise times of several μs, pulse durationof several 10 μs).
• Switching on and off large consumers and transformers, lightning strikes in the vicinity.
As standard, our Power Distribution Boxes are not equipped with protection against transient overvoltages. Should defects on any installed instruments frequently occur due to transient overvoltages or if the power outlet circuits are to be subsequently protected against transient overcurrents, most INDU-ELECTRIC Power Distribution Boxes can simply be fitted with Class 2 overcurrent diverters. In this case, the varistors of the overcurrent diverters must be tested at regular intervals.

Short-circuit rating

If the main Power Distribution Box is fed by low-voltage transformers and the connection paths are very short, very high short-circuit currents that exceed the current limit of the main fuse may flow under certain circumstances. The short-circuit current must then be calculated under the actual operating conditions. The standard short-circuit strength of INDU-ELECTRIC Power Distribution Boxes is:

16 – 125A 6 – 10kA
160 A 16kA
250 – 400A 20kA

Transportation and storage

For transport and storage, Power Distribution Boxes with a connected current of less than 63 A can always be stacked. Make sure that the protective covers of the built-in electrical protection devices and the covers of the built-in sockets do not become damaged. Power Distribution Box with a connected load of 63 – 250 A up to a height of 500 mm must only be stacked if the enclosures are equipped with stacking fittings. The 54 series Power Distribution Box are fitted with these as standard.
If the Power Distribution Box are to be lashed down, e.g. on a pallet, make sure that the straps are lashed directly above the handle sides and never in the middle of the Power Distribution Box.

Connection extension leads

To avoid thermal overload of the sockets, the cross-section of the cables supplied by the Power Distribution Boxes must comply with the requirements of VDE regulations 0298-4 (Use of cables and insulated lines for power installations, Part 4: Recommended values for the current-carrying capacity of cables for fixed installation in and on buildings and of flexible cables).
In the case of longer lengths and special ambient conditions, please note that the switch-off times of the SCPD may change unfavourably due to the line resistance, so that the values specified by the standards cannot be met. Please refer to the corresponding tables in VDE 0100 Part 410. The limit lengths specified in this standard, resulting from the switch-off times, need not be observed if the fault protection is ensured by a residual current operated protective device (RCB or RCBO) (see also VDE 0100 Part 410).

Warranty Conditions

The mobile Power Distribution Boxes are manufactured according to the applicable directives, standards and regulations.
As part of final inspection and testing, the required inspections and tests are performed on all Power Distribution Boxes and recorded. This ensures that all products are built to the same high quality standard. Should a supplied product be defective or in an unacceptable condition on delivery, we will repair or replace it free of charge under the legally applicable warranty conditions. Any fault must be reported immediately and no later than three days after receipt of the product.
The warranty applies only if the product is used for its intended purpose and under the specified operating conditions.