HI-THERM BB-346-A Black impregnating varnish

Varnish

HI-THERM BB-346/A

▪ Black impregnating varnish

▪ Excellent adhesion and flexibility

▪ Superior heat resistance, suitable up to 215°C

▪ Suitable for insulating systems in class A, B ,F and H

▪ Military approved, qualified under MIL-V-1137A, grade CB, type M, and MIL-I-24092,

type M, class 180

▪ UL approved (File OBOR2.E317427 and OBJS2.E317429), included in 130°C, 155°C,

180°C, and 220°C insulating systems

Description

HI-THERM BB-346/A Black Baking Varnish is a modified polyester based varnish suitable for the impregnation of

electrical machinery windings in Thermal Classes A, B, F and H. Long use experiences have proven HI-THERM BB-

346/A to have an excellent dip tank stability, even in the worst using conditions.

Compatible with the following magnet wires coatings: Amide-Imide, Polyamide, Polyurethane-Polyamide, Polyvinyl

Formal, Polyurethane, Epoxy, Polyvinyl Formal-Polyamide, Polyimide, Textile, Polyester Amide-Imide, Polyester.

HI-THERM BB-346/A has a heat life of 20.000h. at 215°C and of 40.000h. at 205°C as determined by ASTM D-3251

(twisted pairs) specifications, using a polyester amide-imide magnet wire

Applications

Impregnation of stators, low speed rotors, transformers, windings, coils.

Processing guidelines

HI-THERM BB-346/A is suitable for both atmospheric pressure and under vacuum impregnations; if necessary, it can

be diluted with DOLPH’S T-200 thinner. The excellent wetting properties assure maximum penetration using

atmospheric or vacuum impregnating systems

The following cycle is recommended as a starting point in the treatment at atmospheric pressure of most units:

1. Dip into the varnish for 15-30’.

2. Drain 15-30' (to obtain a high build-up, we suggest to shorten the draining time).

3. Place in the oven and bake according to one of the following cycles : 3-5 hours at 135°C, or 2-4 hours at 150°C

or 1-2 hours at 165°C (times must be taken when unit reaches the baking temperature)