Kakadu Combiner Box

This guide shows how to mount an AERL Kakadu Combiner Box, prepare its cable entries, and terminate the battery and load power cables ready for commissioning.

The Kakadu Combiner Box is the companion combining enclosure for the AERL Kakadu 120 battery cabinet. It parallels the DC output of up to four Kakadu 120 cabinets onto a common busbar and presents a combined output to the inverter or load equipment.

Ratings

How Many Cabinets Can Be Combined

The gland plate provides eight battery input pairs (1B to 8B). Each Kakadu cabinet presents two pairs of positive and negative terminals, so the enclosure combines a maximum of four Kakadu cabinets.

Three output pairs (P1 to P3) are provided for the connection to the inverter or load equipment. Internal busbars are 3 mm × 25 mm, giving a cross-sectional area of 75 mm². Internal fusing is for short circuit protection only. Overcurrent protection shall be installed to protect both cables and bus bar.

Typical Application

The combiner box is designed for a three-phase Selectronic SP PRO SPLC1202 system, or similar. The three outputs allow one connection to each inverter.

The Kakadu Combiner Box carries the full combined battery current and is a live DC busbar assembly rated to 500 V DC. Read this chapter before opening the enclosure.

1.1Who May Install This Equipment

Installation, termination and commissioning must be carried out only by a licensed electrical worker competent in battery energy storage systems, and must follow AS/NZS 3000 and AS/NZS 5139.

1.2Voltage Classification

This enclosure is rated to 500 V DC and must be treated as low-voltage DC throughout. Apply low-voltage isolation, signage and access-restriction requirements in accordance with AS/NZS 3000.

The Kakadu 120 is a 140.8 V nominal battery. Establish the actual bank voltage for the system in front of you before starting work.

1.3Isolation Before Work

1. Shut down the inverter or load equipment in accordance with its own manual.
2. Open the battery-side isolation for every cabinet feeding the combiner box.
3. Open the load-side isolation between the combiner box and the inverter.
4. Prove dead at the combiner box busbars with an instrument rated for the full system voltage before touching any conductor.
5. Apply lock-out / tag-out to every isolation point for the duration of the work.

1.4DC Arc Hazard

A short circuit across the combined busbar will not self-extinguish the way an AC fault does, and the severity rises sharply with system voltage. A sustained DC arc is a life-threatening hazard, not an equipment-damage risk.

Use insulated tools rated for the system voltage, remove watches and rings, and never leave a loose lug, washer or dropped fastener inside the enclosure.

Refer to AS/NZS 5139:2019 for guidance on arc flash hazard.

1.5PPE

Select PPE in accordance with AS/NZS 5139:2019 Clause 3.2.4 and Clause 3.2.4.4. As a minimum this will include insulated gloves rated for the full system voltage, eye or face protection, and arc-rated clothing appropriate to the assessed hazard. Do not work alone on an energised bank.

2.1Package Contents

Unpack the combiner box and confirm all items are present and undamaged before starting. Report any transit damage to AERL before installation.

2.2Site and Mounting-Surface Requirements

Manual handling

Use a two-person lift when mounting the enclosure.

Location

The enclosure measures 750 × 400 × 132 mm (W × H × D), weighs 18 kg ±5% and is rated IP55 — protected against dust and against water jets from any direction.

Choose a location that is:

• Shaded and clear of direct sunlight.
• Space wide enough for a 750 mm enclosure plus the mounting bracket overhang — and a clearance of 150 mm. Refer to Chapter 03. Allow space for the cable tray.
• On a solid substrate — masonry, concrete or steel-framed panel — capable of carrying the 18 kg enclosure plus the mass of the terminated cables.
• Allow space for easy installation and access to the combiner box for maintenance.

Warning — not suitable for coastal installation

Do not install in coastal areas subject to salt mist.

3.1Step 1 — Mark the Mounting Points

Mark four mounting points on the wall at a recommended height of 1.0–1.5 m above the ground, with a spacing of 773 × 250 mm.

Note — the fixing centres are wider than the enclosure

The enclosure body is 750 mm wide, but the horizontal fixing centres are 773 mm. The fixings therefore sit 11.5 mm outboard of each side of the body, on the mounting brackets — not on the back panel within the footprint.

Use a spirit level to check the enclosure is level.

3.2Step 2 — Verify the Hole Positions

Position the combiner box against the wall and check that the marked hole locations line up with the enclosure's mounting points.

3.3Step 3 — Drill and Fasten

Drill the four mounting holes, insert the supplied expansion bolts — or a suitable alternative fixing appropriate to the mounting substrate — and fasten the combiner box securely to the wall.

Check the enclosure is level once more after tightening, and confirm all four fixings are loaded evenly.

4.1Step 4 — Unlock and Open the Door

Use the supplied key to unlock the enclosure door.

Open the door fully and support it while working.

Before touching anything inside, re-confirm the isolation and prove dead at the busbars per Chapter 01.

5.1Step 5 — Remove the Lock Nuts and Terminal Bolts

Remove the lock nuts fitted with the PG cable glands required for the cable installation, and remove only the M8 terminal bolts required, depending on the number of systems being combined.

Leave any unused glands and terminal bolts in place. All unused entries must stay sealed and vermin-proof.

Keep the removed hardware together and in a tray. A loose M8 bolt left in the base of the enclosure is a short-circuit waiting for the first vibration.

6.1Cable Sizing

The recommended conductor sizes and lugs are:

The selected cable must meet the requirements of AS/NZS 5139.

6.2Step 6 — Pass Cables Through the Glands First

Important

All power cables must be passed through the waterproof cable glands before the cable lugs are crimped. A crimped lug will not pass through the cable gland. Getting this out of order means cutting the lug off and re-terminating.

Work in this order for every conductor, without exception:

1. Cut the cable to length, allowing service loop inside the enclosure.
2. Feed the cable through its waterproof gland.
3. Strip the conductor.
4. Crimp the lug.
5. Apply heat-shrink and label the cable.

Tighten each gland onto the cable once the conductor is in its final position, so the gland grips the sheath and not the insulation of a strained cable.

6.3Step 7 — Crimp the Cable Lugs

Crimp cable lugs onto the power cables. All cable lugs are secured using M8 bolts, torqued to 13 N·m on final assembly (see Chapter 07).

Crimp with the correct die for the lug, apply the full number of crimps for the barrel length, and finish each barrel with adhesive heat-shrink. Confirm every crimp with a pull test before installing the cable.

7.1Step 8 — Terminate the Power Cables

Connect all B+, B−, P+ and P− power cables to their designated entry positions and terminals.

The gland plate is divided into four labelled groups:

An earth point is provided at the left-hand end of the plate.

7.2Step 9 — Mandatory Input and Output Overcurrent Protection

Mandatory — all input and output cables must be protected

Each combiner input must be protected by a 150 A DC MCB or a 150 A HRC fuse, fitted on the battery feed upstream of the combiner. Each combiner output must be protected by a 250 A DC MCB or a 250 A HRC fuse, fitted on the inverter feed downstream of the combiner.

Each output supplies a maximum of one Selectronic SP PRO SPLC1202. Do not connect a load with >250 A continuous current rating.

Note: The combiner's internal fuse cannot provide overload protection for the busbar — its rating is far above the busbar's continuous rating. The downstream device carries the whole of the busbar's load current and is what protects it against overload. Omitting it leaves the busbar without overload protection.

AS/NZS 4509, AS/NZS 5139 and the manufacturer's guidelines must be followed for electrical protection.

Working practice at the busbar:

• Land one lug per stud unless the schematic explicitly shows otherwise.
• Keep each cabinet's two pairs together in adjacent positions, and label them to the cabinet they serve.
• Observe the washer and lug stacking order shown on the assembly.
• Torque every M8 terminal connection to 13 N·m with a calibrated torque wrench, and mark each completed connection with torque-seal.
• Re-check polarity on every conductor before closing up. A reversed connection on a paralleled DC bank is a destructive fault, not a nuisance, and the severity rises with system voltage.
• Dress and clamp the cables so no mechanical load is carried by the terminals.
• Label both ends of every cable.

Complete these checks before the bank is energised.

8.1Before Closing the Door

1. Confirm every M8 terminal connection is torqued to 13 N·m and torque-sealed.
2. Confirm polarity on all B+, B−, P+ and P− conductors.
3. Confirm every input in use has a 150 A DC MCB or a 150 A HRC fuse fitted, and every output in use a 250 A DC MCB or a 250 A HRC fuse.
4. Confirm all glands are tightened onto the cable sheath and all unused entries are sealed.
5. Confirm all unused terminal bolts remain fitted.
6. Remove all tools, offcuts, swarf and loose hardware from the enclosure.
7. Confirm all cable labels are fitted and legible, identified to the cabinet each pair serves.

8.2Electrical Verification

8. Carry out an insulation resistance test between each pole and earth with the battery cabinets isolated, in accordance with AS/NZS 3000.
9. Confirm continuity of the protective earthing conductor to the enclosure.
10. Confirm no continuity between poles.

Refer to the Kakadu 120 Installation and Operating Manual for the start-up and shutdown sequence.

10.1Warranty

The Kakadu Combiner Box warranty is 2 years, starting 30 days after AERL dispatches the product. Conditions apply: see the Kakadu 120 Battery and Combiner Box Warranty Statement, at aerl.com.au.

10.2Support

Before you contact AERL, note the number of Kakadu cabinets combined, the inverters connected and what the Kakadu HMI shows. Contact AERL support on 1800 950 865 or [email protected].

10.3Change Log