Dry type transformer is one of the transformer, the advantages of small volume, convenient maintenance, but at the same time the system is in use process, there are many problems, such as winding fault, switch fault as well as the core, etc., affect the normal operation, the general meaning of common small make up is dry type transformer fault is analyzed, and measures for troubleshooting, together to get to know and have a look,
A transformer temperature abnormally elevated:
's abnormal running dry type transformer are mainly on the temperature and noise,
If high temperature anomaly, specific measures and steps are as follows:
1, check the thermostat and the thermometer is failure;
2, check the machine and indoor ventilation situation is normal;
3, check the transformer load and thermostat probe into the situation to exclude the thermostat, blowing device failure, under the condition of normal load, temperature rising, should be identified as transformer internal fault, should stop operation, the overhaul,
The causes of abnormal temperature rise are:
1, local layer or transformer winding interturn short circuit, the internal contacts are loose, increased contact resistance, on the second line have short circuit conditions and so on;
2, the partial short circuit transformer core, clamping core with the screw core insulation damage;
3, long-term overload operation or accident load;
4, cooling condition deteriorated,
Two, transformer abnormal voice processing:
Transformer noise points and normal and abnormal sound, sound is normal by the "buzzing" sound emitted by the transformer excitation, it is changing with the size of the load have strength; When there is abnormal sound of transformer, the first analyse the sound is in transformer internal or external,
If it is internal, may produce parts:
1, the core clamping loose not tight, will make "jingle" and "shout".
2, the core is not grounded, would send a "breakdown peel" wow peel "mild" discharge.
3, the switch will happen at the poor contact "squeak" "crack" sound, and it is larger with the increase of the load;
4, casing surface oil pollution is serious, "hissing" sound,
If it is outside, may produce parts:
1, the overload operation produce heavy "buzz";
2, high voltage, large transformer noise and sharp;
3, lack of phase operation, transformer sound than usual sharp;
4, the grid system is magnetic resonance occurs, the transformer will be uneven degree of a noise;
5, when the low voltage side is short circuit or ground, transformer will send huge "rumbling" sound;
6, when the external connections are loose, arc or spark,
7, simple temperature control failure handling
Three, the core of low insulation resistance:
Is mainly due to the air humidity is bigger, lead to low insulation resistance of dry type transformer be affected with damp be affected with damp,
The solution:
With iodine tungsten lamp placed under low pressure coil bake for 12 hours in a row, including core, high and low voltage coil as long as it is because of be affected with damp be affected with damp lead to low insulation resistance, insulation resistance value of the improved,
Four, the core of insulation resistance is zero:
Real connection between that metal may be due to the burr, wire, etc., into the core by paint on both ends overlapping between the core and clip pieces; Connected to the foot foot insulation damage caused by core; With metal fall into the low pressure coil inside, causing plate connected to the core,
The solution:
With lead wire of low voltage winding down the passage between the core level tong, sure no foreign body, check the foot insulation situation,
Five, the power should pay attention to what matters:
General power supply bureau sending 5 times, there are also three times, before sending to check whether there is metal bolts and iron core on foreign body; Insulation distance is in accordance with the sending standards; Electrical function is normal operation; Attachment is correct; Wave components are sending standards; Check whether there is any condensation phenomenon on body; Check shell has no make small animals into the holes (especially the cable into the line); Either there is no discharge,
Six, when sending shock, shell and floor plate discharge:
The shell (aluminum alloy) conduction between plate is not good, belong to the poor grounding,
The solution:
With 2500 m Ω shaking table board insulation breakdown or shell scrape off each connection part film and copper wire connected to ground
Seven, when work handover testing withstand voltage, why a discharge:
There are several possible, pull plate positioned to clip a JinChu discharge, can use the infant in the spear, the drawing board and clip a conductive good; Block creepage, especially high voltage products (35 kv) has produced this phenomenon, to block reinforced insulation treatment; High voltage cables and connection point or to tap a plate, Angle of connecting pipe insulation distance is close, also can produce discharge need increase insulation distance, to tighten bolts, check whether there is high voltage coil wall of dust particles, due to the grain moisture absorption, can cause the insulation is reduced, and discharge,
Eight, the dc resistance unbalance rate exceeds bid:
Users are doing handover testing, tap bolt looseness or testing method, will cause the unbalanced dc resistance rate of overweight,
Check the project:
1) whether there is a resin inside each tap;
2) whether fastening bolt connections, especially low copper platoon connecting bolts;
3) contact any paint or other foreign material, such as joint interface is useful sand paper burnish is smooth,
Nine, travel switch exception:
Travel switch is in the operation of the transformer charged, for operator protection device, such as transformer charged, in open any one door shell, the stroke switch contact shall be closed immediately, make the alarm circuit connected and alarm,
Common faults:
When the doors were not alarm, close the door after still alarm,
Possible reasons:
Travel switch attachment, fixed bad or the travel switch failure,
The solution:
1) check the line and terminal blocks, make its good contact,
2) replacement travel switch,
3) check and tighten bolts positioning,
Ten, Angle have to take over the burning:
Carefully check the high voltage coil blackened parts, with a knife or iron scrape off the black spot, if you remove leakage from carbon black red, illustrate the coil inside the insulation without damage, the coil is mostly good, by measuring the ratios to determine whether a coil short circuit, if the test than normal, that failure is caused by external short-circuit arc and Angle to take over the burning,
