UPS or Uninterrupted Power Supplies is an important unit of the AC Power Conditioning Systems the world over and along with AC Servo Stabilizers, CVT (Constant Voltage Transformers) or Ferro Resonant transformer do the conditioning of raw AC power coming from electrical utilities and supply clean and regulated power to the devices connected to them..
The raw AC power coming from the Utilities will have noise, break, black out, brown out , variation in voltage and frequency because of the load connected to it and also because of transmission effect. Normally the generating station will be away in a remote area and transmission lines take the power generated through out the country by the action called Transmission and distribution (T& D ). The power generated will be at a higher voltage level of 33KV or 11 KV which will be then boosted up to 230/400KVA and then transmitted through power transmission towers and when it reaches the distribution sub station the voltage is reduced to 11 KV and finally when it comes to the customer from the road side transformer it will be 230 V AC in India or 110V AC as in US. This voltage also can be either single phase or three phase at the preference of the user or customer.
As said the AC voltage will have the problems mentioned above which can damage sensitive instruments like Refrigerator, Air conditioners, Computers etc and warrant the use of power conditioning equipments called UPS, Inverters, Servo voltage Stabilizers etc to get controlled and clean Power.
UPS Systems
All the previous mentioned equipments only regulate the AC voltage and does not help you if the input is having noise, burn out and black outs and power failure. in this case only we have advantage of UPS which gives continuous power even when power fails at its input and removes all the electrical noise and continues to energise the instruments connected to it.
The very basic UPS consists of
- A charger to charge the battery connected to the UPS when AC mains is available. * An Inverter to invert the DC voltage of the battery to AC * A set of batteries depending on the power of the UPS * A transfer switch to switch over from AC to mains (Inthe case of interactive UPS and Standby UPS)
There are three basic types of UPS available in the Market. they are
- Standby UPS Systems . The Inverter which supplies the AC voltage will be switched 'ON' only when mains fail by a static switch from the mains to inverter and the inverter continues to supply power till the batteries drain out. The batteries are getting charged when mains is available. This is a simple systems and cheaper. * Line Interactive UPS. This type has only one transformer which charges the batteries and gives output from the inverter always . But when mains fail the static switch changes from Mains to battery and the Inverter always gives out power and connected to the load.
Points to be taken care off.
- Select a UPS depending on your load requirements and never overload it.
- Do not connect loads which do not require an UPS as the power is precious as when power is absent it gives life support. Load like printers should not be connected to UPS.
- Select the batteries properly since these batteries support your load when mains fail. Batteries should be kept clean and proper maintenance to be carried out.
- Once power fails try to save all the work and be ready to switch off as the battery will cut off if their threshold voltage is reached.
- keep the UPS in a ventilated area and easily approachable.As it is a secondary power people keep them at places which is normally not approachable. I have once seen it being kept in a toilet. At another time in a canteen where one fellow kept one cup of tea on the top and while talking with his colleague poured the tea on the UPS and burned it by shorting.
- Have all the spare parts ready and have the routine maintenance carried out.
- Use proper power cables for connection.
If you follow the above your UPS and Stabilizers will give long time support and service.