20kV - 30kVA Cast Resin Dry Type Transformer , Three Phases , Two Winding , Power Distribution
- Both the HV and LV windings are surrounded and filled by glass fiber mats, no filler in epoxy resin during casting under vacuum condition. The windings will be solid cylindrical overall, with high mechanical strength and high reliability and no partial discharge.
- Fire and explosion proof, do not pollute the environment. Coil winding insulation materials such as glass fiber with self-extinguishing properties, and will not arcing when short-circuit happened; heat the resin will not produce toxic of harmful gases.
- Coil does not absorb moisture, core clamps have a special corrosion protection layer, and transformers can be abnormally running in the 93% relative humidity condition. No need special treatment during intermittent service.
- High short circuit withstanding capability lightning impulse level.
- Thin resin in both inner and outer of coil can ensure good heat dissipation. Normally the transformer is air cooling type(AN). Force air cooling type(AF) can be used on any transformer, in order to improve short-term overload capacity, to ensure safety operation.
- Lower loss level are reduce the running cost , and all transformers are maintenance-free.
- Small size, light weight, small floor space, low cost of installation, no need to consider the discharge of oil, fire and other fire control facilities and stand by power.
- Because there is no fire and explosion possibility, it can be easily installed in any place of load center and fully close to the power consumption equipment, thus reducing the loss on the transmission line.
- Good performance on heat resistance and anti-aging.
- 10．Key technology parameters are in good balance, the load is well-distributed, which is reduces the amount of non-characteristic harmonic wave effectively .
Cast Resin Dry Type Transformer, Low Noise, Low Loss and Low Partial Discharge.
|I Basic Information || || |
|1||Rated Voltage ratio||kV||20kV / 0.433 kV|
|1.02||Applicable Standards|| ||IEC 60076|
|1.03||Manufacturer|| ||Pearl Electric|
|1.04||Country of Origin|| ||China|
|II Electric Performance || || |
|2.06||Insullation Class|| ||Class H|
|2.07||Temperature Rise (@40℃ ambient temperature)||K||125K|
|2.08||Cooling Method|| ||AN|
|2.09||Tapping Ranging|| ||±2*2.5%|
|2.1||Vector Group|| ||Dyn11|
|2.14||Load Loss (@120℃)||W||1060|
|2.15||Local Partial discharge||pC||<10PC|
|2.16||Impulse Withstand Voltage (HV/LV)||kV||75/0|
|2.17||Power Frequency Withstand Voltage|
|2.18||Rated Duration of Short Circuit||s||2|
|III Materials & Accessories || || |
|3.01||Core Materials|| ||Silicon Steel Sheet|
|3.02||Winding Materials|| ||Copper conductor/foil|
|3.03||Insulation methods|| ||HV vacuum cast / LV impregnant|
|3.04||Main Insulation Materials|| ||Epoxy Resin|
|3.06||Sensor for Temperature Alarm and Trip||pcs||Yes, contact provided|
Transformer insulation life time
The total time between the initial state for which the normal transformer insulation life time is
considered new and the final state when due to thermal ageing, dielectric stress, short-circuit
stress, or mechanical movement, which could occur in normal service and result in a high risk
of electrical failure
AN cooling :cooling by natural air ventilation
AF cooling: method of cooling to increase the rated power of the transformer with fan cooling
Effect of loading beyond nameplate rating
Normal life expectancy is a conventional reference basis for continuous duty under design
ambient temperature and rated operating conditions. The application of a load in excess of
nameplate rating and/or an ambient temperature higher than specified ambient temperatures
involves a degree of risk and accelerated ageing. It is the purpose of this part of IEC 60076 to
identify such risks and to indicate how, within limitations, transformers may be loaded in
excess of the nameplate rating.
2 General consequences
The consequences of loading a transformer beyond its nameplate rating are as follows:
– the temperatures of windings, terminals, leads, tap changer and insulation increase, and
can reach unacceptable levels;
– enclosure cooling is more sensitive to overload leading to a more rapid increase in
insulation temperature to unacceptable levels;
– as a consequence, there will be a risk of premature failure associated with the increased
currents and temperatures. This risk may be of an immediate short-term character or may
come from the cumulative effect of thermal ageing of the insulation in the transformer over
NOTE Another consequence of overload is an increased voltage drop in the transformer.
GB/T10228 , GB1094.11 , IEC60076-11 , DIN42523