A control system manages, commands, directs, or regulates the behaviour of other devices or systems using control loops. It can range from a single home heating controller using a thermostat controlling a domestic boiler to large Industrial control systems which are used for controlling processes or machines.
For continuously modulated control, a feedback controller is used to automatically control a process or operation. The control system compares the value or status of the process variable (PV) being controlled with the desired value or setpoint (SP), and applies the difference as a control signal to bring the process variable output of the plant to the same value as the setpoint.
For sequential and combinational logic, software logic, such as in a programmable logic controller, is used.
There are two common classes of control action: open loop and closed loop. In an open-loop control system, the control action from the controller is independent of the process variable. An example of this is a central heating boiler controlled only by a timer. The control action is the switching on or off of the boiler. The process variable is the building temperature.This controller operates the heating system for a constant time regardless of the temperature of the building.
In a closed-loop control system, the control action from the controller is dependent on the desired and actual process variable. In the case of the boiler analogy, this would utilise a thermostat to monitor the building temperature, and feed back a signal to ensure the controller output maintains the building temperature close to that set on the thermostat. A closed loop controller has a feedback loop which ensures the controller exerts a control action to control a process variable at the same value as the setpoint. For this reason, closed-loop controllers are also called feedback controllers.
Decommissioning is a general term for a formal process to remove something from an active status. Specific instances include:
- Decommissioned roads
- Greenfield status of former industrial sites
- Nuclear decommissioning
- Decommissioning in Northern Ireland of paramilitary weapons
- Decommissioning pennant, where a navy ship wears an extremely long commissioning pennant at the end of its commission overseas
- Demobilisation of soldiers
- Ship decommissioning
Following is a simple flowchart to help you solve common power supply–related problems:
- Check the AC power input. Make sure the cord is firmly seated in the wall socket and in the power supply socket. Try a different cord.
- Check the DC power connections. Make sure the motherboard and disk drive power connectors are firmly seated and making good contact. Check for loose screws.
- Check the DC power output. Use a digital multimeter to check for proper voltages. If it’s below spec, replace the power supply.
- Check the installed peripherals. Remove all boards and drives and retest the system. If it works, add items back in one at a time until the system fails again. The last item added before the failure returns is likely defective.
Many types of symptoms can indicate problems with the power supply. Because the power supply literally powers everything else in the system, everything from disk drive problems to memory problems to motherboard problems can often be traced back to the power supply as the root cause.
OFGEM encourages competition in areas where this can make a positive difference for customers. This should mean that customers connecting to the network get fairer prices and better service.
There are two categories of work when providing new electrical utility connections:
- Non-contestable work is work that can only be undertaken by the host Distribution Network Operator (DNO). For example the DNO is the only body permitted to determine the point of connection to the network.
- Contestable work may be undertaken by a suitably accredited Independent Connections Provider (ICP). Contestable works include the installation of cables, sub stations and other plant associated with the new connection.
Our Generator Connection Points are designed to restore power to critical applications. They can be fitted inside or outside of a building, allowing a safe and quick connection of a back-up generator to your facility’s electrical system when required.
You need to know that, when it’s needed, the contingency power can be relied upon. We use the highest quality switchgear in all our products, giving you confidence.
It is vital that the generator is completely isolated from the mains supply. This ensures that the generator is not attempting to power up the whole neighbourhood, but also ensures that it does not electrocute a utility worker trying to restore the mains supply.
Any generator set used for emergency or primary source must have periodic service and maintenance performed. Setting up a planned maintenance schedule, and performing all associated testing will insure generator availability upon demand. Possibilities of generator failure increase when service and maintenance checks are not performed.
Planned maintenance can be defined as performing service, maintenance, inspections and testing on a generator set on a pre-determined schedule.
There is no universally accepted definition, although some industry standards do specify various minimum voltages, above which is considered high voltage. These definitions are generally based on safety considerations or the voltage where arcing will occur. It would be convenient if high voltage was universally accepted to start at a nice round number, for example, 1kV. Instead, we’ve seen voltages as low as 5V referred to as high voltage. In contrast, according to the Bonneville Power Administration, to be considered high voltage, it needs to be 100kV and above!
Technical Issues: Certainly, for most engineers, high voltage is different voltage. It’s no longer engineering-as-usual. Other variables enter into the design and manufacturing processes. You need to take into consideration creepage distance, insulation thickness, corona and geometrical arrangement. It’s no longer a good idea to use your finger to see which component is running hot. Components exhibit unexpected behaviour, like resistors that change value as a function of applied voltage.
A load bank is a device which develops an electrical load, applies the load to an electrical power source and converts or dissipates the resultant power output of the source. A load bank includes load elements with protection, control, metering and accessory devices required for operation. Load banks can either be permanently installed at a facility and permanently connected to a power source or portable versions can be used for testing power sources such as standby generators and batteries. Load banks are the best way to replicate, prove and verify the real-life demands on critical power systems.
Load banks are used in a variety of applications, including:
- Factory testing of turbines and engine diesel generator sets
- Periodic exercising of stand-by engine generator sets
- Battery and UPS system testing
- Ground power testing
- Load optimisation in prime power applications
- Removal of carbon build-up on generator piston rings
- Load rejection tests
- Data centre tests (electricity and air-conditioning)
Competency standards in the UK are defined by the Sector Skills council Summit Skills. Qualifications certificated by awarding organisations such as City and Guilds and EAL are based on these National Occupational Standards. Once qualified and demonstrating the required level of competence an Electrician can register with the JIB (Joint industry Board) for an Electrotechnical Certification Scheme (ECS) card. Electrical competence is required at Level 3 to practice as an electrician in the UK. The electrical industry is one of the few that require a trade test to be achieved prior to being fully qualified. This is known as the AM2.
Electricians can demonstrate further competence by studying further qualifications in Design and Verification of Electrical Installations or in the Test and Inspection of Electrical Installations. These qualifications can be listed on the reverse of the JIB card.
The Electricity at Work Regulations are the statutory document that covers electrical installations. Further information is provided in the non-statutory document BS7671 – Requirements for Electrical Installations otherwise known as the Wiring Regulations currently (2013) in their 17th Edition. Installations that comply with BS7671 are deemed to have met the EAWR. Electrical Installation in domestic properties is governed by Part P of the Building Regulations and electricians have to register certain aspects of their work in domestic properties with the local building control authority.
With the exception of the work described in Part P of the Building Regulations there are no laws that prevent anyone from carrying out electrical work in the UK. A possible result of this is that during 2010/11 and in 2011/12 there were 3,822 domestic electrical fires in Great Britain, resulting in 14 deaths. Organisations such as the Electrical Safety Council are working hard to educate the public not to use electricians who are not fully qualified or competent and to check the ElectricSafe register to ensure an Electrician has been deemed competent.
They say time is money and that’s why Pleavin Power prides itself on offering a range of same day solutions to save time and money.
Our services are available 24hrs – 7 days a week
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Your duties as an event organiser
Event organisers, contractors and others using electrical equipment must do all that is reasonably practicable to ensure that electrical installations and equipment at an event are properly selected, installed and maintained so as not to cause death or injury.
What you should know
The following guidance will be useful and should be read in conjunction with GS50.
Note: GS50 outlines the risks and your legal duties and general advice on managing electrical safety. It also gives more specific advice on ways to prevent electrical danger at fixed electrical installations.
Guidance: Planning and managing temporary electrical installations
Consider the following:
- Layout (performance areas, traders, public areas, access routes etc)
- Power requirements
- Details of and access to any mains (utility) power supply
- Location of any existing overhead power lines or buried cables
- Environmental conditions
- Electrical environment as defined in BS 7909
- Emergency power requirements
Do you need to create a output that differs from the standard voltage? We can provide you with a range of transformer hire solutions. Whether you need to hire a transformer to compensate planned or sudden power shutdowns, or for seasonal changes in power demands, we have a power rental solution for every situation.
We have a wide range of only the best transformers available for hire. When renting one of our transformers, 100% reliability is ensured. Our modular units are provided with maximum protection for high and low voltages, and we offer a capacity from 100 kVA up to 8000 kVA each. The optimal voltage selection means our transformers can be easily deployed within other networks.
UPS systems are available to hire range from 1-500kVA with suitable battery based on your requirements. We can supply single phase, 3-phase, rack mounted, standalone & modular products. Pleavin Power offers a complete UPS hire package including the delivery, installation, commissioning & battery build if required, all the way through to the de-commissioning and the removal from a site at the end of the UPS rental period.