LT CAPACITORS STANDARD RATINGS
COSPOWER deals with APP type (Film + Foil) design LT capacitors. In LT capacitors there are standard and non-standard voltage capacitor units. Our LT capacitors conforms to IS:13585 – 1994. For standard range – 5, 10,15,20 and 25 KVAr, 440 V internally delta connected type 3 phase capacitor units. For higher rating one or more single units are coupled to form capacitor ‘bank’ of the required rating. But the maximum single bank that can be offered is 200 KVAr. This is due to limitation in current. For capacitor banks above 200 KVAr we recommend banks in 2 steps, which can be connected in parallel.
LT CAPACITORS NON-STANDARD VOLTAGES
For heavy-duty application higher voltage LT capacitor are provided. These are specially required in harmonic infested systems where 6% or 7% inductors (series reactors) are provided. Although the voltages can be ‘tailor made’, Cospower is offering capacitors with rated voltage of 480 V and 525 Volts.
ALL POLYPROPYLENE LT CAPACITORS
APPLICATION
The Capacitors are rugged design and suitable for heavy duty application and most suitable for switching application in APFC panels. Today most of the industries have machine which generate harmonics. This is bound to overload the capacitors and hence the capacitors should be suitable for such application. Our APP capacitors are designed precisely for such application.
Non-self healing type APP capacitors
The construction each element will consist single layer of polypropylene film (dielectric) sandwiched between 2 layers aluminium foil (conductor) and each element is provided with internal element fused. No of elements are connected in parallel based on the rating of capacitor units and as per design criteria and formed in stacks. These stacks are connected in delta and the complete assembly is inserted in CRCA container after which the container is completely sealed with only one opening for oil impregnation. The container in then impregnated with oil under vacuum such that oil completely soaks the dry assembly and enhances the dielectric property of the capacitor element. After the process of oil impregnation is over the capacitors are subjected to all the routine test as per Indian Standard after which the final painting and assembly is done.
SERIES REACTOR
Series Reactor has become almost an integral part of capacitor application these days. Cospower provided 6% or 7% series reactors for such applications. The reactors designed by us are or iron core, dry type construction with either aluminium or copper conductors. It is generally of ‘F’ insulation class and designed and the linearity is designed based on the application.
TYPICAL SPECIFICATION OF LT CAPACITORS WITH REACTORS:
| I | GENERAL INFORMATION | |||||
|---|---|---|---|---|---|---|
| a | Applicable standards | IS: 13585 Part 1,1994 | ||||
| b | System Frequency | 50 | ||||
| c | System Details | 3 phase solidly earthed system | ||||
| d | Location | Indoor | ||||
| e | Altitude | upto 1000 metres above Mean Sea Level | ||||
| II | CAPACITOR BANK DETAILS :- | |||||
| a | Quantity | 1 | 1 | 1 | 1 | 1 |
| b | No of phases | 3 | 3 | 3 | 3 | 3 |
| c | System voltage | 440 | 440 | 440 | 440 | 440 |
| d | Output at system voltage in KVAr | 3.78 | 7.55 | 15.11 | 18.88 | 37.76 |
| f | Rated Output in KVAr | 5.00 | 10.00 | 20.00 | 25.00 | 50.00 |
| f | Rated Voltage in KV | 525 | 525 | 525 | 525 | 525 |
| g | Rated Current in Amps | 5.50 | 10.99 | 21.99 | 27.49 | 54.98 |
| i | Type of Connection | 3 ph internally delta connected | ||||
| j | No. of Units in banks | 1 | 1 | 1 | 1 | 1 |
| m | Rated output of individual capacitor unit | 5.00 | 10.00 | 20.00 | 25.00 | 50.00 |
| g | Rated current of individual capacitor unit | 5.50 | 10.99 | 21.99 | 27.49 | 54.98 |
| k | Rated capacitance in mfd | 31.09 | 62.10 | 124.24 | 155.29 | 310.58 |
| l | Capacitive reactance in ohms per phase | 55.072 | 27.572 | 13.782 | 11.026 | 5.513 |
| III | OTHER DETAILS :- | |||||
| a | Type of banking arrangement | Loose units offered for panel mounting | ||||
| b | Incoming terminal arrangement | Cable box for PVC cable | ||||
| c | Permissible overloads | 110% of rated Voltage or 130% of rated output or 130% of rated current | ||||
| d | Power frequency withstand voltage KV rms | 3 | ||||
| d | Limiting ambient temperature, Deg C | 50 | ||||
| e | Watt Losses per KVAr | Less than 0.6 | ||||
| f | Mode of fuse connection Internal | fuses | ||||
| g | No. of Ceramic type bushings, Nos. | 3 | ||||
| h | Discharge device :- | External Discharge Resistors | ||||
| i | Residual Voltage | 50 volts or less | ||||
| ii | Time | less than 1 minute | ||||
| i | Type of imp regnant used | Non-PCB oil | ||||
| j | Dielectric material | Polypropylene film | ||||
| k | Conducting medium | Aluminium Foil | ||||
| IV | SERIES REACTOR :- | |||||
| a | Percentage of reactor | 7.0% | 7.0% | 7.0% | 7.0% | 7.0% |
| b | Rated output in KVAr | 0.350 | 0.700 | 1.400 | 1.750 | 3.500 |
| c | Rated Voltage in volts | 525 | 525 | 525 | 525 | 525 |
| d | Rated Current in Amps | 5.50 | 10.99 | 21.99 | 27.49 | 54.98 |
| e | No. of phases | 3 | ||||
| f | Type | Dry Type | ||||
| g | Type of core and cooling | Iron core aircooled | ||||
| h | Location | Indoor | ||||
| i | Rated impedance Ω/phase | 3.855 | 1.930 | 0.965 | 0.772 | 0.386 |
| j | Rated inductance mH | 12.277 | 6.147 | 3.072 | 2.458 | 1.229 |
| k | Temperature rise over ambient | 40 deg. Capacitor | ||||
| l | Insulation Class | Class H | ||||
| m | Material of winding | Copper | ||||
| n | Linearity | 180% of rated current | ||||
| o | Type of terminals | Pad type terminals |