Queen Victoria Apartments – Grundfos 3-Phase Pump Replacement

We were recently contacted by the general manager at the Queen Victoria Apartments on Fullarton Road in Rose Park because their entire rear car park was flooding from the previous night’s rain.

It was around 8:30 am that the call came in, and we managed to attend by 10 am the same day. What we found was a large cast iron grate in the floor of the car park; it had clearly not been opened for a long time.

The first challenge was going to be getting the grated lid up and trying to get an understanding of what was going on. Once the lid was off, it was still very hard to see what was going on.

We sent one of the team back to the yard to collect a large submersible pump with 50m of lay flat hose so we could empty the pit to the street and see what was going on inside the lifting chamber. This was a very serious problem as there were some very impressive motor cars parked down there along with some big electrical transformers.

Diagnosing a Failed Car Park Stormwater Pump

Once the pit was emptied, we had a better idea of the problem. The chamber was the size of a 20-foot shipping container; you could fit a small car inside it.

The pumped discharge line was an 80 mm pressure pipe and was connected to a pump approximately 1. 2m high and 1m round in diameter.

The next step was to get the old pump out, which had clearly failed. Getting a pump such as this out requires a small tripod and an electronic mechanical winch, as the weight of a pump like this is 210 kilograms and it is sitting 3m below the ground.

Upon getting the pump above ground, we performed a few electrical tests which proved that the electrical motor has burnt out. Getting a replacement pump with the correct specifications would not be off-the-shelf. We contacted Grundfos and gave them the specifications of the old Franklin motors pump, and they then needed to get their engineers to work out what pump would suit the situation.

This kind of failure sits at the heavy end of commercial stormwater pump replacement work across Adelaide, and it needed both plumbing and electrical capability on site.

Specifying a Custom Grundfos Super Vortex Pump

Grundfos came back to us the next day with a new pump solution; it will be a 415volt Super Vortex. This pump can move water up to 44 metres of head and at 25 litres per second.

The pump would have to be custom-made in their head office in NSW and would take approximately 1 week to build and deliver to us in South Australia. In the meantime, we would need to set up a temporary system to protect the property in the event of any rain.

The lay-flat hose and temporary pump we used to empty the pit could stay on site until the new pump arrived from Grundfos.

Working with Grundfos three-phase pump solutions on a custom build is common for commercial pits of this size, especially when the failed unit is an older Franklin motor setup that cannot simply be swapped for a stocked domestic pump.

In the meantime, while we waited for the new pump to arrive, we would need to source some 80mm pressure pipe, 80mm brass swing check non-return valve, 80mm screwed adaptors, red hot glue and primer and an 80mm Gibault fitting from local plumbing supplier Tradelink. Having all these fittings pre-assembled and glued together before the new installation would help minimise leaks on the day from a failed glued connection.

Preparing the Pit for Installation Day

On the day of the installation, we had a vacuum truck from Tiger Vac to attend first up to completely suck the entire base of the pit clear of any silt, rocks and leaves to give this brand-new pump the best possible chance of performing well for a long time. Given the pit is a confined space, we had to re-set up air quality monitoring and extraction and fresh air fans to ensure our worker’s safety, like the first time we attended, but this would be a much longer visit installing the new pump.

The pump was delivered to Rose Park by Mt Barker Pumps and Irrigation, who are a Grundfos dealer in South Australia. Due to the size of the pump, it was delivered in a timber crate in order to protect the pump during transport from NSW via road freight.

Installing the New Discharge Line and Auto Coupling

Once the pump was unpacked, it was time to plumb up the new 80mm discharge line with the 80mm swing check positioned for future access to maintain the brass swing in case of blockages. We always undo the hex nut first and lubricate the threads with silicone grease to prevent corrosion and nut seizing, which would prevent us from servicing this if ever required.

The auto coupling set (32 kilograms), which the pump comes with, needs to be bolted on; this elevates the pump approximately 100mm off the base of the pit floor to ensure even suction of the liquid out of the chamber when the pump is in operation.

The next step is to secure the pump to the tripod lifter and lower the pump into the pit. Once this is done, the 80mm discharge pipe needs to be fitted to the existing 80mm discharge pipe using the Gibault fitting we purchased previously.

The bolts which squeeze the Gibault fitting closed need to be carefully tightened using a torque wrench. After this has been done, it’s time to start filling the pit so we can test the pump once the electrical wiring has been completed.

Jobs like this are a strong example of why correctly sized heavy-duty submersible stormwater pumps matter in large underground chambers, and why installation planning has to cover lifting, discharge plumbing and electrical commissioning together.

Commissioning the 3-phase Pump

Given the pump is 3-phase, we need to ensure that the windings spun in the correct direction, and this requires some technical assistance from Grundfos themselves over the phone. The size of the chamber, as previously mentioned, is huge and took nearly 2 hours to fill so that we could run some tests on the new pump.

Once the chamber was full, we could run a series of tests on the new pump and its floats to ensure it is working as per the manufacturer’s specifications. This pump’s impeller was the Super Vortex 80mm, which could suck a tennis ball up and spit it out to the street exit on Fullarton Road!

After all this time and effort, the day had come to an end, and it was time to pack up and say goodbye to another successful commercial submersible stormwater pump installation for a Rose Park apartment complex.

What This Job Shows About Commercial Pump Failures

Car park and basement stormwater stations can sit quietly for years until heavy rain exposes a failed motor. When the chamber is this large and the pump weighs more than 200 kg, recovery needs confined-space controls, lifting gear, temporary flood protection, and a custom replacement rather than a same-day stock swap.

For similar commercial call-outs, see our Pirie Street basement sewer station emergency and the planned North Adelaide basement sewer pump changeover. Regular inspections remain the best way to catch failures before flooding starts.

Need Commercial Stormwater Pump Help in Adelaide?

Mayfair Plumbing provides emergency response for flooded car parks, failed stormwater pits and large commercial submersible pump replacements across greater Adelaide. Call 0429 361 819 or book a commercial pump inspection if your building’s stormwater station has failed or needs replacement.