Transformer Insulation Components – Casein Glue
- White glue (Elmer’s glue) made from casein, the nutrient protein in milk.
- The casein is separated from milk by processes called coagulation and precipitation.
- A water based glue
- It allows the diffusion of moisture and oil impregnation
- Used in high voltage applications
- For use in areas with high dielectric stress
- Available in tins of 33kg
- Safety data sheet available on request
- Related Products
PREFILZ ® 2082
PREFILZ ® 2082 consists of PET-felt impregnated with a modified epoxy resin in B-stage.
PREFILZ ® 2082 is flexible and compressible and can be formed and cured under temperature and pressure.
PREFILZ ® 2082 can be used e.g. as separator and filling material in the overhang parts of high voltage windings or for the production of moulded parts.
Format Rolls thickness 2.2 mm – width: maximum 630 mm Tape from 15 mm width upwards
PREFILZ ® 2082 is supplied interleaved
Minimum 6 months at 20 °C
Minimum 12 months at 5 °C
Curing conditions: 1 hour at 170 °C or 3 hours at 150 °C.
A loosely woven cotton or terylene tape without tracer – Selfedge – CLASS A 105°C
APPLICATION : Taping of HV coils before consolidation pressing
Code Size GC025 25mm x 50m
RFA ΙΙ -R™
Rotor Flux Analyzer: a second generation advanced tool to find rotor winding shorted turns in turbine generators and high speed synchronous motors
- Instant analysis of rotor winding condition at a fixed operating load
- Where needed, ability to analyze tests at different loads for a more certain prediction of rotor winding condition.
- Able to perform a spot measurement, or automatically acquire results over days during normal generator load changes, without test operator intervention
- Works with conventional wedge-mounted flux probe, or the Iris stator tooth-mounted TF Probe™, which can often be retrofitted with the rotor in-place
Synchronous Generator And Motor Rotor Windings
- The rotor insulation must withstand severe electrical, mechanical, and environmental stresses. Insulation failures can result from many factors including:
- Mechanical wear, especially that caused by frequent load cycles
- Distortion, breakage and migration due to centrifugal mechanical loading and thermally induced expansion/ contraction cycles
- Overheating due to overloading/over excitation or inadequate or diminished cooling
- Local overheating at high resistance brazed joints and at shorted turns
- Contamination from ventilation or copper dusting resulting in surface tracking between turns or to ground
- Over-voltages induced from system events or from firing circuits in static exciters.
- An insulation failure can translate into electrical connections between turns, and eventually a catastrophic winding to ground fault.
A turn-to-turn short is the most frequent rotor insulation failure mechanism. Turn shorts can result in:
- Thermal imbalance of the rotor leading to mechanical vibrations
- Magnetic imbalance in the flux resulting in mechanical vibration of the rotor
- Increased rotor temperature and subsequent insulation degradation
- Overheating resulting in insulation failure and a ground fault with the potential for a second catastrophic ground fault
- Inability to reach the rated MVA rating for the machine
- Decreased generator power due to higher electrical losses
Flux monitoring via permanently mounted air gap flux probes is a proven technology in synchronous machines to determine if turn-to-turn shorts have occurred in the rotor winding. Flux measurement provides the most direct means of monitoring the condition of rotor windings on-line, yielding the information on the integrity of coils’ inter-turn insulation. This information is critical in planning maintenance, diagnosing abnormal vibrations, and verifying new and rewound rotor integrity.