Switchboard Testing & Factory Acceptance Testing

E&B Industrial Electrical is a Perth-based electrical contractor providing hands-on switchboard and MCC testing support. The work covers inspection and workmanship checks, point-to-point wiring verification, control and functional testing, and support through Factory Acceptance Testing before equipment is dispatched.

E&B is an electrical contractor, not an engineering consultancy, certification body or accredited testing laboratory. The role is doing the testing work and supporting the process — not issuing independent certification or design approval.

What gets tested, and to what extent, depends on the equipment, the project specification and the scope agreed beforehand. Nothing on this page is a fixed test schedule.

Background

What is Factory Acceptance Testing?

Factory Acceptance Testing is the structured check carried out on an assembled switchboard or MCC before it leaves the workshop, to verify that it has been built and wired as intended and that it operates in line with the agreed project documentation and testing requirements.

The practical argument for FAT is simple. A wiring error, a mislabelled feeder or an interlock that does not behave correctly is a modest job to correct on a workshop floor, where the board is accessible, the drawings are to hand and there is no production pressure. The same issue found during site commissioning is a different proposition — the board may be installed, cabled and energised, access is limited, and a delay there can hold up an entire commissioning programme.

FAT is usually witnessed by the client or their representative, and typically produces a documented record of what was tested along with a list of any items requiring attention.

It is worth being realistic about what FAT does. It substantially reduces the risk of defects reaching site, but no testing programme identifies every possible defect, and some faults only appear once equipment is installed, loaded and running in its actual environment.

MCC testing

Testing motor control centres

MCCs bring their own considerations, and the testing needs to reflect how the particular board is designed and built rather than following a generic list.

Fixed and withdrawable feeders

Fixed feeders are straightforward to test in place. Withdrawable feeders add the mechanical side — correct engagement of the primary and secondary contacts, racking mechanism operation, shutter function and the interlocking that prevents a bucket being withdrawn or inserted in the wrong state.

Control circuits and indication

Control circuits get proved feeder by feeder: start and stop, local and remote selection, permissives, and the indication that tells an operator what the feeder is actually doing.

Interlocks

Interlocks exist to prevent a dangerous or damaging operation, so they warrant testing in their own right rather than being assumed correct because the feeder runs.

VSD feeders

Drive feeders involve the drive itself, its control interface and any associated protection or bypass arrangement — each needing checks appropriate to how it has been configured.

Because MCC arrangements vary so much between manufacturers, vintages and projects, the testing scope should be set against the specific board and the project requirements.

Busbar systems

Busbar and connection inspection

Busbar systems and bolted connections carry the full load of the board, and a poor connection is both a reliability problem and a thermal one. Inspection and testing here is worth doing carefully.

Visual inspection and verification of assembly

Checking that the busbar system has been assembled as designed — correct bar sizes and arrangement, supports and insulators in place and undamaged, correct phase arrangement and identification, and appropriate clearances maintained.

Torque verification

Where the project or manufacturer specifies torque values for bolted connections, those can be verified and recorded as part of the scope. Values come from the specification or the manufacturer's requirements for that hardware, not from a general rule of thumb.

Insulation resistance testing

Insulation resistance testing between phases and to earth, carried out at the voltage and in the manner the specification requires, with the board configured appropriately for the test.

Low-resistance and micro-ohm testing

Where required, low-resistance measurement across bolted joints can indicate whether a connection has been made properly. Interpreting those readings is not a matter of comparing against a universal figure — the result depends on the joint arrangement, bar material and section, the measurement points used, temperature and the test method. Results should be assessed against the project requirements and, where relevant, compared between similar joints on the same board.

For that reason we do not publish generic pass or fail values. What constitutes an acceptable result comes from the applicable standard or the project specification for the equipment in question.

After the test

Punch-list and rectification support

Testing usually finds something. That is the point of doing it.

Items that commonly come out of a FAT include wiring that does not match the drawings, labelling errors or omissions, interlocks not operating as intended, components not matching the specified type or rating, mechanical adjustments needed on withdrawable equipment, and work that is simply incomplete.

E&B can assist with identifying and documenting these items, and with rectifying them as part of an agreed scope — including re-testing the affected items once the work is done, so the record reflects the board as it is actually being delivered.

Where a defect is a design matter rather than a build matter, that gets referred back to the responsible party rather than resolved in the workshop.

Workshop & site

Workshop and site support

Testing support can be provided during workshop assembly and refurbishment, at the point of FAT, and on site as part of agreed installation and commissioning activities.

During assembly or MCC refurbishment, testing as the work progresses is generally more effective than leaving everything to the end — problems are found while the board is still open and accessible.

On site, support can cover verification after installation, re-testing of items affected by transport or installation, and assistance during commissioning within an agreed scope. You can see the broader range of work on the MCC and switchboard services section of our services page, or across our mining and industrial electrical services.