LAK 372-2000
APPLICATION
It is suitable for noise reduction in small transformers and moisture protection, anti-tracking for tropicalisation; suitable for all types of electrical equipment.
CHARACTERISTICS
Impregnation enamel LAK 372 is anti-tracking varnish; it provides toughness, imperviousness, insulating properties in different natural conditions. The enamel dries rapidly in thin film to give very effective sealing off of electrical leakage paths together with excellent noise reduction characteristics. The cured product has an excellent resistance to transformer oils, moisture according to BSEN 600464 type 1.1 (IEC 600464) and is suitable for use in class B and F insulating system. Enamel is fungicide; that results to very low risk of fungal attack. It is particularly suitable for tropicalisation of electrical motors and transformers.
- Anti-tracking
- On air drying alkyd
- Clear, golden
- Available pigmented version
- Available aerosol version
Tab.1 Processing data
| Flow time | 25 °C | [s] BS 3900 PTA6 B4 | 170 - 220 |
| Non-volatile content (non-pigmented version) |
[%] | 40 - 42 % | |
| Density (non-pigmented version) |
[kg/m3] | 960 - 990 | |
| Flash point | [°C] | 27 | |
| Shelf life | max. 21°C | [month] | min. 12 |
| Drying time: touch dry – stage A non tacky – stage B1 Full cure |
[min] [min] [h] |
15 45 - 60 24 |
Processing
Application process:
- Brush (viscosity set by producer)
- Dipping (required viscosity – dilution with T4)
- Spray (required viscosity – dilution with T4, or use aerosol version)
Procedure for dip impregnation of smaller components:
1. Dilute LAK 372-2000 with T4 to achieve a desired viscosity – achievement of required width of winding impregnation.
2. Immerse winding to enamel 372-2000 for 1-10 minutes
3. Drain winding for 15-30 minutes.
4. Cure
* at ambient 45 minutes – 2 hours, winding can be processed, but only 50-70% of properties have developed and there is still residue of solvent.
* at ambient 24-48 hours 95% of properties is developed and there are only trace quantities of solvent still present. In most cases this trace of solvent is diffused slowly into the atmosphere causing no further problem
If the windings are used or packed in materials such as polystyrene some attack can occur. By impregnation of dense winded windings there is a risk of sticking of more solvent in winding, therefore it is used higher temperature for cure.
Procedure, which will be picked by client, depends on winding size, required film, cure temperature, stove effectiveness.
Cure time depends on winding size a type.
Tab.2 Cure time
| Cure time | 15 min | 45 - 60 min | 24 - 48 h | 2 - 3 h |
| Temperature [°C] | 21 | 21 | 21 | 80 |
| Enamel properties | touch dry | winding can be formed | cured | cured |
Tab.3 Properties of cured varnish
| Dielectric strength ASMD115 | [kV/mm] | 72 |
| Dielectric strength ASMD115 after immersion in water for 24hrs | [kV/mm] | 30 |
| Anti-tracking (comparative index) | 180 | |
| Flexibility (diameter 5mm) | no cracks up to 180° bending | |
Health and safety
Refer to Material safety data sheet.
Packing
Impregnation enamel 372 is delivered in 25,5 l cans.
