Select a case study to read from the list below:
- Quantum's fast response keeps Northumbrian Water pumping
- Northumbrian Water Bran Sands
- Dwr Cymru (Welsh Water) keep a high quality service throughout a major site upgrade
- Northumbrian Water to save £100,000 energy costs with ABB drives
Quantum Controls took only two hours to solve a problem for Northumbrian Water (NW) when it needed to hire a drive at very short notice.
NW called Quantum Controls at 3pm one Friday afternoon with a request to hire a variable speed drive to replace an existing drive at one of its pumping stations. By 5pm the same day, Quantum Controls had a pre-tested, 440V, 500kW drive on site, together with three engineers to complete the installation.
Because the site ran on 660V, Quantum Controls also needed to supply and install a step-down transformer to match the supply to the drive, together with a step-up transformer to match the drive's output to the needs of the water pump.
Another factor was the limited space available at the site, due to the size of the existing equipment. Because of this, the hire drive and transformer could not be placed as close together as they normally would, requiring Quantum Controls to use longer cables.
NW is a frequent customer of Quantum Controls and is a major user of variable speed drives. John Fielding, Acceptance Engineer for NW, says: "The fast reaction and support we received from Quantum Controls meant that we had no disruption to service on one of our major sites in the North East. I would not hesitate to recommend Quantum Controls and will happily continue to use them."
Following the installation of a Variable Speed Drive for energy saving the treatment works Anaerobic Digester, Northumbria Water have seen the following results.
There are 6 off 90KW pump motors supplying 3 anaerobic digesters originally running at fixed speed with a star delta start at 1500 RPM. Each Digester runs 24/7 (8736 hours per annum) and the pumps run duty standby. (4368 hours per pump per annum.)
Following the installation and testing of two ACS800’s the speed was reduced down to 900 RPM at which point the digester could run without causing excess foaming.
Quantum Controls then came back to site to measure the difference in kW’s between two pumps running simultaneously, with the first pump being Star Delta and the second being VSD controlled.
We can assume all other variables remain equal as both digester tanks are the same size and were full and both pumps are the same age.
In order to work out the costs for running each pump we have used the area average of 8p per kWH
Cost of Upgrade
The cost per pump is £4875 this is based on one engineer being assisted by an NWL engineer and taking two days to upgrade each Star Delta panel to a VSD panel, this also allows for the cost of the VSD and all ancillary equipment needed when upgrading the panel. This cost is also fully inclusive of any commissioning.
Overall saving based on these results would be £106,928.64 this equates to approximately 75% of the current costs.
The estimated cost of project is £29,250.00 (including delivery and Labour) divided by annum savings of £106,928.64 means a payback period of 0.27 years or to put it another way approximately 100days. These figures are based on reducing the speed of the motor by 40% from 1500rpm to 900rpm. The savings for this have also been proven with the first two installations.
Further savings are possible as reducing you kWH you’re reducing your Co2 footprint by 721.80 tonnes and with the current carbon tax credits this reduction equates to an additional saving of £8661.66.
This brings to total savings up to £115,590.24 with a return on investment of 92 days.
When Dwr Cymru (Welsh Water) needed to upgrade the full Motor Control Cabinet (MCC) and power supplies controlling the Mescoed pumping station, they called upon Quantum Controls to offer a unique solution to the problem of maintaining the water supplies to the surrounding area.
The problem is a common one for Water companies, as removing the old MCC and fitting / testing and commissioning the new MCC requires days, and in some cases weeks to complete. The means the pumping station cannot be used during this time and in the worst cases could leave local areas with a limited or even no water supply. The only other solution is to use Diesel pumps which require a great deal of mechanical work to install and are not as environmentally friendly as using the mains electricity supply.
In order to keep the Mescoed site running throughout this transition period Quantum Controls hired Welsh Water two 400kW Variable Speed Drives (VSDs) and enough cable to ensure the stand alone cabinets were situated away from the main MCC, so as not to hinder either the removal of the existing MCC, or the fitting of the new MCC. Quantum Controls were also able to install and commission these cabinets prior to the site upgrade taking place, which meant fewer people on site at any one time.
In addition to the water standard build control panels supplied, Quantum were able to provide provisions for a generator supply, and provide a separate supply to an LV distribution board for on-site lighting from each of the panels. The control panels provided also meant that there was no need to change the control methods used on site. This all meant the site could continue to run as normal under any conditions, which importantly meant there would be no adverse effect for Welsh Waters customers.
Russell Lewis, Project Coordinator at Welsh Water said "Quantum Controls and Dwr Cymru were able to work closely together to ensure all the sites requirements would be maintained throughout this complex site upgrade. From our point of view working with Quantum proved a great success, so much so that we have now made them our company standard for this type of work. I would gladly recommend Quantum for any future projects of this kind."
Northumbrian Water is set to save over £100,000 a year on pump running costs following a project with ABB Drives Alliance member, Quantum Controls, to install ABB low voltage AC drives on its anaerobic digester.
An anaerobic digester uses micro-organisms to break down biodegradable material such as sewage waste. The company was experiencing a problem with the pumps on the three digester tanks that make up the anaerobic digester at its Bran Sands sewage treatment works on Teesside.
Each digester tank had two 90 kW star-delta controlled pumps with no speed control. When run at full speed, the pumps caused a foaming of the liquid in the tanks, making it difficult to control the digestion and to measure the sludge levels.
As well as processing the sewage sludge, the digesters also produce methane. This is supplied to gas fuelled engines which contribute up to 4 MW of power, helping to offset the site’s total power requirement. The foaming also interfered with the volume of methane produced.
Northumbrian Water and Quantum Controls investigated whether it could achieve a form of pump control that would prevent the foaming. Quantum Controls fitted two low voltage AC drives to one of the digester tanks. As well as giving the ability to reduce the motor speeds, avoiding the foaming, Quantum Controls also demonstrated a substantial cost saving for the application through the reduction of the energy used by the motors. Quantum Controls measured the difference in power between two pumps running simultaneously, with the first pump being star-delta and the second being controlled by a low voltage AC drive.
Quantum Controls calculated that the overall saving based on these results would be £107,000, giving a payback period of 0.27 years. As well as the monetary savings, Northumbrian Water will also be able to reduce its CO2 footprint by over 700 metric tons a year, giving an additional saving of £8,600 under the current UK carbon tax credits scheme. This brings total savings up to £115,000, with a return on investment of 92 days.
Daniel Fitzsimons, Utilities Account Manager for Quantum Controls, says: "At first it was not clear how much the pumps would need to be slowed to prevent the foaming. We initially did a test that involved fitting two low voltage AC drives on a temporary basis. This would also tell us if the reduction in pump speed would cause any temperature problems with the existing motors.
"Using the drives, the speed of the pumps was reduced from 1500 rpm to 900 rpm, allowing them to pump without causing excess foaming. We also found that there were no problems with excessive pump temperatures."
Ian Clark of Northumbrian Water says: "This project was a good example of the partnership which exists between NWL and one of our preferred suppliers. We gave Quantum the basic specification and they supplied the equipment to suit. Due to our limited on site resources, they also installed and commissioned alongside NWL technicians".
ABB (www.abb.com) is a leader in power and automation technologies that enable utility and industry customers to improve their performance while lowering environmental impact. The ABB Group of companies operates in around 100 countries and employs about 130,000 people.