EMPOWER3DELECTRICAL ENGINEERING · BAC ASSETS
Switchboard Selector
E3D-BAC-EL-TOOL-001 · Rev H
BAC ADGs · AS/NZS 3000 · 61439.1 ·.2 ·.3 · 3017 · 4836

Project details

These carry through to the specification output and the deviation schedule. Nothing is stored — the page holds them in memory only, so print or copy the output before closing.

A board whose sections differ in Form, metering or supply is specified as one selection per section, each identified here, under the same board designation. The project register consolidates them into one schedule.

Document control

These appear on the face of the specification. An issue status above Draft states that a named engineer has checked the document, so it cannot be set without a checker and their RPEQ registration.

[E3D] issue control — GDL-001 §1

Issue status

Scope. This tool specifies low voltage switchboards and distribution boards at Brisbane Airport Corporation assets — the T1 to T6 standard types of E3D-BAC-EL-GDL-002. It does not cover substations or their LV cubicles, HV switchgear, embedded generation enclosures under ADG-602, or bespoke BAC substation designs under ADG-601 §4.4. Applying it to those assets will produce a wrong specification. It applies the requirements of E3D-BAC-EL-GDL-001 and does not replace it. BAC guidelines are marked "Uncontrolled if Printed" — the source revision set this release was verified against is stated on every specification it produces.

Step 1 — Role and environment

Role determines construction, environment and the RapidTest, zencontrol and metering provisions. It sets the type. Fault level, at Step 2, sets only the Form.

1.1  What is the role of this board?

Select the closest match. If the board sits between two roles, choose the more onerous.

[E3D] GDL-002 §2 type series

1.2  Where is the board located?

Sets enclosure construction, IP rating, door hardware and minimum design life.

[BAC] ADG-601 §4.3.3.1.2, §4.3.3.1.4, Table 9

1.3  Is the board exposed to public view?

Determines the external finish colour.

[BAC] ADG-601 §4.3.3.1.2

Step 2 — Fault level and Form of separation

The Form is set by how critical the loads are and by the prospective fault level at the board. Where the two indicate different Forms, the higher is selected.

2.1  Confirmed prospective fault level at the board

From the electrical protection and grading study. If not yet confirmed, enter the design assumption and record it as provisional.

[BAC] ADG-601 §4.2.5 · Table 10
kA

2.2  How critical are the loads supplied?

This is the second input to Table 10 and is assessed independently of fault level.

[BAC] ADG-601 §4.3.3.1.5 · Table 10

2.3  Does this main switchboard serve a Terminal or other major building?

Determines whether the Form 3bih concession is available.

[BAC] ADG-601 §4.3.3.1.5 note

Step 3 — Supply and metering

Supply size sets the number of metering points, which drives metering cubicle sizing. Two separate thresholds apply — one for how many meters, one for whether they are CT meters.

3.1  Board supply capacity

The rating of the supply feeding this board.

[BAC] ADG-601 §4.3.3.3.4 · ADG-635 §4.6.6
A

3.2  Load per phase — for the CT metering threshold

CT metering is triggered independently of the meter count, by either of two figures. Enter both if known.

[BAC] ADG-635 §4.6.2, §4.6.4
A
A

3.3  Does the board carry an essential / non-essential split?

Affects the metering point count and, where the board is a terminal MSB, the load allocation against ADG-601 Table 6.

[BAC] ADG-635 §4.6.6 · ADG-601 Table 6

3.4  Are there UPS or priority supplies on this board?

Above 250 A these attract their own metering points.

[BAC] ADG-635 §4.6.6

3.5  Does the board have a second incomer — a standby or alternate supply?

A generator, standby feeder or alternate mains connected through a changeover arrangement. The higher of the two fault levels governs the Form, and the changeover carries its own requirements.

[BAC] ADG-601 §4.3.3.5 · [AS] AS/NZS 3000 §7.3
A
kA

Step 4 — RapidTest

TN-52 applies to all new final circuit switchgear containing RCD/RCBO protection, and to retrofits. Deployment is set by building typology, and the physical requirements drive board size.

4.1  Does the board contain final circuit RCD or RCBO protection?

Includes mechanical services switchboards, UPS distribution and comms room distribution.

[BAC] TN-52 §4

4.2  Building typology and maintenance responsibility

Determines whether RapidTest is deployed now, or space is allowed for future installation.

[BAC] TN-52 §5.1

4.3  Is this a modification to an existing switchboard?

The exemption at TN-52 §5.1 has two limbs and both must be satisfied.

[BAC] TN-52 §5.1

4.4  Modification extent and existing board condition

[BAC] TN-52 §5.1

4.5  Pole count and spare poles

24-channel modules match the pole count on each chassis, with a minimum 25% spare channels on completion. TN-52 §6 does not state the denominator; Empower3D calculates the 25% against poles served — the conservative reading, standing interpretation SI-02.

[BAC] TN-52 §6 [E3D] standing interpretation SI-02
poles
poles

Step 5 — zencontrol

Where the board serves lighting within zencontrol's scope, the equipment is housed inside the switchboard enclosure with segregation — making it a sizing input, not a downstream fit-out item.

5.1  What lighting does this board serve?

zencontrol covers internal and direct building-mounted lighting only.

[BAC] TN-58 §4

5.2  Which network precinct?

VLAN is selected by proximity to the building. Confirm the BBMD for the VLAN with the EBI integrator during design.

[BAC] TN-58 §5.2.1

5.3  Does the board supply emergency or exit lighting?

Emergency lighting must never be integrated to zencontrol on any BAC facility.

[BAC] TN-58 §2 · ADG-605 §4.2.3.9.7

Step 6 — Construction details

The remaining determinations that change what is built. Each is a discrete ADG-601 §4.3 requirement with a conditional element.

6.0  Is the board intended to be operated by ordinary persons?

An ordinary person is neither a skilled nor an instructed person. This is the first of the four criteria in AS/NZS 61439.3 §1 that decide which part of the series the assembly is built and verified to.

[AS] AS/NZS 61439.3 §1 · AS/NZS 3000 App. K3.2, K3.3

Do the outgoing circuits also meet the remaining DBO criteria?

Both must hold: every outgoing circuit is rated 125 A or less, and every outgoing circuit is protected by a device of a type intended to be operated by ordinary persons — a circuit breaker, RCD, RCBO or fuse-link to IEC 60898-1, 61008, 61009, 62423 or 60269-3. The fourth criterion, rated voltage to earth not exceeding 300 V, is met by the BAC LV supply at 230 V and is not asked.

[AS] AS/NZS 61439.3 §1 · §8.5.3

6.0.1  Form designation to AS/NZS 61439.2

BAC Table 10 gives a bare Form number. A bare number does not say whether the terminals for external conductors are separated from the busbars, so it cannot be built to. These two answers resolve it to a designation the manufacturer can quote against.

[AS] AS/NZS 61439.2 §8.101 · Table 104 · Table 104.101

Are the terminals for external conductors separated from the busbars?

By what means is the internal separation achieved?

6.1  Distribution board chassis

The requirement is derived from the supply you entered at Step 3. Only one further question is needed. §4.3.3.2 expresses the exemption for single phase below 64 A; Empower3D applies the requirement to all three-phase boards as a standing interpretation — the conservative reading.

[BAC] ADG-601 §4.3.3.2 [E3D] standing interpretation SI-01

Does this board supply critical IT infrastructure?

6.2  Escutcheon arrangement

The exemption for control panels requires both conditions to be satisfied.

[BAC] ADG-601 §4.3.3.1.6

6.3  Withdrawable switchgear

Trucks are required per size where circuit breaker weight exceeds 20 kg.

[BAC] ADG-601 §4.3.3.1.11

6.4  Does the board carry PLC input / output?

The controller arrangement must be agreed with BAC at the commencement of design — before tender documentation issues.

[BAC] ADG-601 §4.2.28.2.1

6.5  Portable generator connection facility

ADG-601 §4.3.3.5 opens "All main switchboards shall be provided with facilities for the rapid connection of a portable electricity generator when required" — it is a main switchboard provision only.

[BAC] ADG-601 §4.3.3.5