Switchboard Transport, Lifting and Site Installation: A Step-by-Step Guide
switchboard transport and installation: Four steps decide the outcome of switchboard transport and installation: splitting the assembly into transportable sections, lifting only from the manufacturer lifting eyes with a sling angle steeper than 60 degrees, levelling the plinth to better than 1 millimetre per metre, and re-tightening all site busbar joints to the specified torque.
Contents
A switchboard built and tested faultlessly in the factory can still cause trouble from day one on site if it is transported badly or installed carelessly. Lifting from the wrong point permanently distorts the frame, an unlevel plinth stops the doors closing, and site busbar joints left untorqued show up months later as hot spots on a thermal image. This article walks through the whole process, from transport preparation to handover inspection.
Shipping Splits and Packaging
Long switchboard rows cannot be shipped in one piece, and the splits have to be planned around both the dimensions of the vehicle and the doors, lifts and corridors of the building. Each shipping section must be labelled with its weight and centre of gravity, and the busbar jointing kits and bolts should be fixed inside the relevant section in numbered bags. Packaging needs desiccant bags, corner protection and a shock indicator, and the sections must be lashed against tipping across their narrow axis rather than along their length. Sensitive devices such as analysers and relays are removed and packed separately where necessary.
Lifting: Eyes, Sling Angle and Centre of Gravity
Lifting is done only from the lifting eyes or transport profiles defined by the manufacturer; the roof sheet, a door handle or a busbar must never serve as a lifting point. The angle between the slings should be kept steeper than 60 degrees, because the sling force grows rapidly as the angle narrows and roughly doubles at 30 degrees. The centre of gravity may not coincide with the geometric centre because of heavy equipment inside the cubicle, so the balance should be checked with the load only a few centimetres above the ground. When a forklift is used, the tines must span the full depth of the enclosure and load must be taken under the base frame.
Plinth, Levelling and Anchoring
The plinth or channel base on which the assembly will sit must be checked with a level or laser before installation, and the acceptable deviation is typically 1 millimetre per metre and 3 millimetres over the whole row. Without correct levelling the frame twists, doors will not close, withdrawable trucks become difficult to rack in and out, and busbar mating faces do not make full contact. Shim plates may be used where necessary, but they must be stainless or galvanised and must not interrupt earthing continuity. Anchor hole positions should be planned so that they do not obstruct the cable compartment or the earthing connection.
Busbar Jointing and Earthing Continuity
| Step | Critical parameter | Typical acceptance criterion |
|---|---|---|
| Lifting sling angle | Angle between slings | Steeper than 60 degrees |
| Plinth levelling | Deviation per metre | Below 1 millimetre |
| Levelling over the row | Total deviation | Below 3 millimetres |
| Busbar bolt torque | Manufacturer torque value | Recorded with a torque wrench |
| Earthing continuity | Transition resistance | Below the declared limit |
| Insulation resistance | Measured value | Above the limit set by the standard |
Site busbar jointing is the most critical step of the installation. Contact faces must be cleaned, the oxide layer on aluminium busbars removed mechanically and a suitable conductive compound applied, and the bolts tightened to the manufacturer torque with a torque wrench. Every tightened joint should be marked and recorded, with the torque values written into the installation report. Protective conductor and frame earthing continuity between sections must also be measured and the transition resistance verified against the declared limit. On painted surfaces the earth connection has to be made through a paint-free contact area.
Post-Installation Checks and Handover
When installation is complete, a pre-energisation checklist should be worked through: insulation resistance measurement, protective conductor continuity, phase sequence, operation of doors and interlocks, re-tightening of terminals that may have loosened in transit, and removal of transport bracing. Desiccant bags must be taken out and filters and ventilation openings cleaned. Reference conditions for later thermographic surveys should be noted before commissioning, and the installation report, torque records and measurement results added to the handover file. Those documents form the basis of the warranty and of the periodic maintenance programme.
Key takeaways: switchboard transport and installation
- Use only the designated lifting points — Lifting from a roof sheet or busbar permanently deforms the frame.
- Keep the sling angle steeper than 60 degrees — Sling force rises quickly as the angle narrows and can exceed the lifting eye rating.
- Verify plinth levelling by measurement — A deviation above 1 millimetre per metre disturbs door and withdrawable unit operation.
- Record every site busbar torque — Joints not tightened with a torque wrench appear as hot spots months later.
- Standard source — IEC publication catalogue: iec.ch.
Frequently asked questions
Is it safe to move a switchboard with a forklift?
Yes, when it is done properly. The tines must span the full depth of the enclosure, the load must be taken under the base frame and the section must be strapped to the mast to prevent tipping. Where the tines reach only the front part of the enclosure, the base frame bends and the whole body twists. For cubicles with a high centre of gravity, a crane is preferable to a forklift.
What transport damage is most common?
The most frequent issues are paint scratches, door hinges losing adjustment, terminal and busbar connections loosening through vibration, and moisture condensation. For that reason all power connections should be torque checked after installation and desiccant bags removed before energisation. Using a shock indicator is helpful because it documents any impact suffered during transport.
Is conductive compound always needed at busbar joints?
On aluminium busbars, yes, because the surface oxide layer is insulating and must be prevented from re-forming after mechanical cleaning. On tin or silver plated copper busbars the manufacturer usually does not require compound, although clean and dry mating faces remain essential. In every case the manufacturer instruction governs, and the compound type must be compatible with the busbar plating.
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- Seismic Withstand and Vibration Testing of Switchboards: Design and Verification
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Devpan supplies its assemblies together with shipping splits, defined lifting points and site jointing instructions, and provides installation and commissioning support on request. Let us prepare your site installation plan together. Related Devpan solution: panel service and maintenance.
