Power Factor Equipment Maintenance
PQE carries out Maintenance on all types of Power Factor Equipment irrespective of manufacture throughout UK. Our engineers are experienced and usually have a range of replacement parts available. Contact Us for more information.
Testing
PAT (Portable appliance testing) is testing the electrical safety of all forms of light electrical equipment, everything from kettles to computers. All results are logged and all items tested are labeled.
In the interests of staff safety, every piece of portable electrical equipment should be PAT tested annually or more frequently if it is subject to heavy use or if damage is suspected.
Insulation Resistance Testing
We are able to test the quality of the insulation of electrical equipment of all types and voltage ranges. This is done simply and quickly on site or, if the suspect item is portable, it can be brought to us. This reduces cost because the time taken is less.
Pressure Testing
We have high voltage testers to check the insulation of cables and medium voltage electrical equipment. AC testing up to 30KV and DC testing up to 60KV is available.
Load Profiling
Carried out to determine power usage by means of a recorder which is installed for several days. This gives the true picture of the load under all working conditions by taking measurements at ten minute intervals on all three phases. The results are the average values of each ten minute period. The maximum and minimum currents drawn whilst the instrument is connected are also recorded.
The information obtained is used to analyse power availability, balance between phases, transformer loading and maximum demand.
The instrumentation used is highly accurate and is not affected by distortion caused by harmonics.
Using panel ammeters or clampmeters to determine power usage is misleading and inaccurate: the reading taken may be valid at the moment of measurement but can be wildly inaccurate five minutes later.
Harmonic Analysis
Distortion on the supply network is caused by the use of power electronics such as variable speed drive equipment. This distortion causes problems, electrical failures, transformer overloading and increased wear in motors.
If one user creates harmonic distortion it can affect neighbouring consumers and hence there are rules governing the levels which are acceptable. If these are exceeded the electricity supplier can penalise the guilty party.
PQE can visit sites where problems are thought to exist and carry out measurements of harmonic levels. A report is produced detailing the results obtained and comparing these with the permissible levels. If distortion is too high we can provide equipment to reduce it to an amplitude below the acceptable limit.
If the distortion is causing problems on site our equipment will reduce or eliminate them.
The test equipment can be used to determine if the harmonics present are generated by the customer or if they are ‘imported’ from elsewhere. This is particularly important from a financial point of view because if the incoming mains is the source of the problem, the electricity supplier can be approached to cure it.
Power System Evaluations
Load monitoring
Load Profiling
Harmonic Measurements
PQE also carry out the following:
Vibration Measurements
Sound Level Measurements
Temperature Measurements
Magnetic Field Strength
PAT Testing
Electrical Pressure Testing
Insulation Resistance Testing
Measuring Harmonics:
Harmonics cause distortion of the mains supply which can result in electrical component failures, malfunctions and increase in wear of bearing surfaces.
They can be caused by either the customer or one of his neighbours. We measure the distortion and determine its source. We are then able to reduce it or advise its cause is external, in which case the electricity supplier may be obliged to "cure" the problem.
Vibration Measurements
Carried out to determine if physical damage is being caused to equipment, either electrical or mechanical, by transmission of mechanical forces. Vibration is a frequent cause of fixing components becoming loose which can lead to electrical connections or contacts failing or burning out.
Sound Level Measurements
Very helpful in detecting wear or incipient failures of motors and all forms of rotating equipment.
Particularly valuable for health and safety considerations, requirements for ear protection, etc.
Temperature Measurements
Non intrusive and no contact electronic thermometers used to measure the temperature of electrical components and commodities. If access can be gained safely, the measurements can be made with the equipment running. If not, they are carried out immediately the equipment is shut off and isolated. Thermal inertia ensures that there is virtually no drop in temperature.
The measurements obtained enable users to ascertain the running temperatures of electrical and mechanical components such as motors, cables, transformers, etc. Ambient air temperature can be ascertained. The results are very useful as, correctly interpreted, they can confirm (or otherwise) that operating conditions and component loading is correct.
Power System Evaluation
Many organisations don’t appreciate power availability is LIMITED. Supply transformers, switchgear and cables all have maximum ratings. Uncontrolled increases in demand will eventually cause overloads which will lead to loss of supply.
Some Consumers often don’t consider their electrical power supply, they take it for granted because "it’s there" (usually) and isn’t causing them any trouble. Many organisations do not monitor, record or control what new machinery is installed, or old equipment discarded.
As well as this, neighbouring consumers’ activities can have a major effect on your supply.
A final, expensive, factor is the "maximum demand" charge. Many tariffs have a maximum demand component the consumer has to pay for, even if the maximum load only occurs for quarter of an hour each month.
We know that many organisations are working in the dark because they don’t know how much energy they are using and how much is available to them. PQE Ltd understands these supply problems, issues and limitations.
We therefore offer the following services:
Load Monitoring - measures and records current in each phase every ten minutes for a week, in order for a true load profile to be obtained, which provides the average, maximum and minimum power usage.
This can be used and compared with the availability charge, if a load decrease is required an informed decision can be made, or even an increase in "Availability Charge" can be negotiated to give an overall reduction.
If the maximum demand load only occurs once or twice a week, considerable savings are possible if use of the pieces of equipment drawing the extra power can be staggered so that the maximum demand goes down and so will the electricity bill.