What does water hammer feel like on a 2,5 m diameter, 12 km pipeline?
The pump, pipework and valves try to jump off their mountings and the sound can be like that of a shotgun blast. As the pressure wave is reflected this impact can continue repeatedly until something fails catastrophically resulting in flooding and disruption to the water supply.
The start and stop profiles built into AuCom’s MVS soft starter have been designed to prevent the harmful effects of potentially dangerous hydraulic transients. Profiles include Constant Current, Current Ramp, Kickstart, TVR soft stop and Coast to Stop.
This means that the mechanical stresses associated with sudden starts and stops in hydraulic systems are eliminated and consequently the life of the pipeline equipment is vastly improved.
AuCom aids Ankara
Protection of equipment was precisely what was needed in the case of the Ankara Emergency Water Supply Project in Turkey’s capital city. Sixty medium voltage soft starters were supplied to ensure a secure and reliable pumping solution to each of the five pump stations along the 130 kilometre pipeline.
Ankara had experienced low snowfall and precipitation during early 2007 coupled with very hot temperatures that depleted water supplies. Ankara’s water system, severely stressed by this drought, was running dangerously low despite strict water restrictions.
The drought placed pressure on the city with many hospitals forced to cancel non-emergency surgeries. Restaurants served meals on paper plates and offered plastic utensils to reduce dish washing. The Mayor asked residents to go on vacation to reduce water use in the city.
To alleviate the water crisis, the city administration created a major infrastructure initiative to support an emergency water supply from the River Kizilirmak to Ankara’s five million residents.
AuCom expedited the emergency water supply delivery by providing a soft starter solution in less than a third of the normal manufacturing time. The drive manufacturer worked closely with Ankara Water Works (ASKI) and the contractor, Ankara Beton, to provide a soft starter solution mindful of the tight deadlines.
Introducing MVS
CHI Control’s MVS medium voltage soft starters are an integrated solution for motor control and protection. They combine advanced soft start and soft stop functionality with extensive motor and system protection, plus a user-friendly interface and complete commissioning diagnostics.
The soft starters are available in either IP42 or IP54 panels, with options for line and bypass contactors, earthing and isolation switches. CHI Control can also design and build panels to meet particular specifications, and offer full applications engineering support at all stages of the design process.
Flexibility
The modular design allows panels to be mounted side by side or standalone; bus bars can be configured to client specification; cabling can enter from above, below or either side of the panels. CHI Control can provide solutions to meet the specific requirements of MVS customers.
Panel configurations extend beyond soft starters to include power factor correction, additional motor protection relays, transition panels with cables or direct bus bar connections, multimotor operation, various control options and RTD relays.
Safety
Safety is a primary concern when designing an MVS solution. Prominent warning signage, air-insulation and isolated control through fibre-optic connections to the control panel are supplied. Air insulation assures long-term reliability. For complete electrical isolation, communication between the low voltage controller and the high voltage power assembly is via fibre-optic cables. Enclosed units include additional physical isolation and safety interlocks for maximum safety.
Installation and servicing easy
MVS drives are easy to install and use. The panels are compact and access is achieved through removable panels on all sides. The drive panels feature bolted construction to prevent unintentional access. This ensures that covers may only be removed with very deliberate actions and eliminates the need for mechanical interlocking.
The compact size of the power assembly leaves room for auxiliary equipment to be installed. Phase arms are easy to inspect and service; the built-in runners slide the arm out of the front of the starter.
Commissioning
For minimal disruption to plant operations the MVS incorporates extensive simulated operation. The soft starter can simulate each protection operation to ensure the starter is signalling as expected and correctly interacting with associated equipment. It can also be tested with a low voltage motor (<=500 VAC), to confirm circuit integrity and identify any errors before full commissioning. This allows installers to thoroughly test the starter and its associated power and control circuits before putting into operation.
Communications
The MVS integrates into existing monitoring and control networks using optional easy-to-install plug-in communication interfaces. Supported protocols include Profibus, DeviceNet and Modbus RTU.
Standards and marine certification
The medium voltage starters have approval across CE, C-tick, CCC, UL and RINU. All AuCom’s starters are available with certification for marine applications from Lloyd’s Register, approved as suitable for installation into LR classed vessels. Additional certification is available on request.
The compact soft starters have been used in many marine applications such as bow thrusters, cargo pumps, compressors and winches. They are well suited to applications such as those on vessels where space is at a premium.
Complete range
Site-wide solutions for soft starters are provided with a range of low voltage starters that complement the MV range. The simplicity of set-up and trip diagnosis and similarity of operation across the entire soft starter range simplifies staff training. CHI Control’s low voltage starters across the CSX, CSXi, IMS2, EMX3 families cover motors rated from 18 to 2400 A (7 to 1600 kW).
CHI’s customer focus
CHI Control engineers, backed by AuCom, aim for a deep understanding of client application, site and potential issues. Having a solution focus instead of a product focus brings customer needs to the forefront.
Engineers analyse client applications to develop customised solutions according to clients’ specific needs. Possible designs based on a wealth of past experience are proposed and discussed in detail to arrive at a tailored control scenario.
Mining applications present their own challenges, which are solved through CHI Control’s experience in dusty, wet, or underground facilities. The company is able to specify, design and supply MVS starters for operation work with conveyors, crushers, fans, pumps and more.
CHI Control provides the project management to meet deadlines and budget. Full project plans with key dates, certification and testing programs are provided in advance. Assistance with on-site commissioning support and training for key personnel is part of the package.
CHI Control is the sole distributor of the AuCom range of products in sub-Saharan Africa available through a network of branches and over 40 distributors. CHI has a nationwide service and support footprint as well as offering support into sub-Saharan Africa. Its 24/7/365 service centres are manned with highly experienced service engineers.
Ankara Emergency Water Supply project
* The project pumps water from the Kizilirmak River to the Ankara city water supply.
* 750 kilolitres of water per day is pumped through three 130 km pipelines.
* Each of the five pump stations has two motor control centres equipped with MVS medium voltage soft starters.
* AuCom supply comprises: 60 6,3 kV MVS units, ranging from 1,2 MW to 2,0 MW; 60 power factor correction panels; 10 transition panels for termination of feed cables and power distribution.
AuCom MVS
* An integrated solution for motor control and protection.
* Combines advanced soft start and soft stop functionality with extensive motor and system protection, a user-friendly interface and complete commissioning diagnostics.
* Phase arms extend easily via built-in runners to allow for quick inspection and replacement.
* Isolated control through fibre-optic connections to control panel.
* Bypass terminals. Retains motor protection and monitoring functions even when the starter is bypassed.
* Soft starters available as either IP00 or fully enclosed panels in IP42 or IP54 options.
For more information contact Rob Hare, CHI Control Components, +27 (0) 11 824 7400, [email protected], www.chi.co.za
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