High Voltage

Thick Film Resistors

F Series

High Voltage

Thick Film Resistors

F Series

Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com

Issue B · 03.02

Welwyn Components

202

Application Notes

Mounting

Due to the high voltage which can appear between the end

cap and any adjacent metal part, resistors should be mounted

at an adequate distance from other conductors.

Resistors may be screwed together to provide an assembly

which will be capable of withstanding any desired voltage,

providing no individual resistor is subjected to a greater stress

or power dissipation than is recommended in this data sheet.

For some high voltage applications it is required to immerse

the components in oil or gas to reduce the effects of corona

and surface tracking. A special lacquer is available, suitable

for immersion in transformer oil of SF6.

When resistors are required to be potted, the preferred

encapsulant is a silicone compound.

For voltage dividers with a low resistance section below the

minimum available value of an F43 resistors, it is entirely

suitable to use an RC Series resistor, available down to 1 ohm.

Standard Quantities Per Box

All Types

10 or 20 per box

Construction

quality ceramic former. Turned brass end caps are fitted. A

helical cut is made into the film to adjust its ohmic value and

finally a sleeve is fitted to provide mechanical protection and

electrical insulation. Resistors for use in oil SF6 can be

supplied with a lacquer protection instead of the sleeve.

Terminations

Three styles of termination are available to permit resistors to

be screwed together in a series chain, with the end members

having axial wires for soldering.

Wire Terminations: Styles D and KU

Non standard wire terminations

available upon request.

Material:

Solder coated copper wire

Strength:

The terminations meet the requirements

of IEC 68.2.21.

Solderability:

The terminations meet the requirements

of IEC 115-1, Clause 4.17.3.2.

Screw Terminations: Styles TU and KU

Material:

Turned brass

Screw Thread:

All caps are tapped UNF - 10 x 4.2

deep. UNF - 10 is 32 TPI, 60° thread

angle 4.72 ±0.07 mm outside diameter,

3.83 mm core diameter.

Coupling Stud:

All KU & TU resistors are supplied with

8 mm long screwed brass studs.

Marking

Type reference, resistance value, tolerance and date code are

legend marked. The resistance values conform to IEC 62.

Solvent Resistance

The lacquer and protective sleeve provide excellent resistance

to all normal industrial cleaning solvents suitable for printed

circuits.

Matched Sets

Matched sets can be supplied for use as voltage dividers.

These may be screwed together to form sticks and, by

selecting the KU type of termination, a wire connection can

be provided at each end of the stick.

Enquiries are welcomed for special resistors and sets when

resistor length, operating voltage or resistance vale is outside

the catalogued range.

Packaging

All components are supplied in boxes.

Maximum

Typical

Load at rated power: 1000 hours at 20°C

∆R%

5

1

Shelf life: 12 months at room temperature

∆R%

0.5

Derating from rated power at 20°C

Zero at 100°C

Noise (µV/V in a decade of frequency)

<2.5

Voltage coefficient of resistance

ppm/V

<25

Performance Data

High Voltage

Thick Film Resistors

F Series

Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com

Issue B · 03.02

Welwyn Components

202

Application Notes

Mounting

Due to the high voltage which can appear between the end

cap and any adjacent metal part, resistors should be mounted

at an adequate distance from other conductors.

Resistors may be screwed together to provide an assembly

which will be capable of withstanding any desired voltage,

providing no individual resistor is subjected to a greater stress

or power dissipation than is recommended in this data sheet.

For some high voltage applications it is required to immerse

the components in oil or gas to reduce the effects of corona

and surface tracking. A special lacquer is available, suitable

for immersion in transformer oil of SF6.

When resistors are required to be potted, the preferred

encapsulant is a silicone compound.

For voltage dividers with a low resistance section below the

minimum available value of an F43 resistors, it is entirely

suitable to use an RC Series resistor, available down to 1 ohm.

Standard Quantities Per Box

All Types

10 or 20 per box

Construction

quality ceramic former. Turned brass end caps are fitted. A

helical cut is made into the film to adjust its ohmic value and

finally a sleeve is fitted to provide mechanical protection and

electrical insulation. Resistors for use in oil SF6 can be

supplied with a lacquer protection instead of the sleeve.

Terminations

Three styles of termination are available to permit resistors to

be screwed together in a series chain, with the end members

having axial wires for soldering.

Wire Terminations: Styles D and KU

Non standard wire terminations

available upon request.

Material:

Solder coated copper wire

Strength:

The terminations meet the requirements

of IEC 68.2.21.

Solderability:

The terminations meet the requirements

of IEC 115-1, Clause 4.17.3.2.

Screw Terminations: Styles TU and KU

Material:

Turned brass

Screw Thread:

All caps are tapped UNF - 10 x 4.2

deep. UNF - 10 is 32 TPI, 60° thread

angle 4.72 ±0.07 mm outside diameter,

3.83 mm core diameter.

Coupling Stud:

All KU & TU resistors are supplied with

8 mm long screwed brass studs.

Marking

Type reference, resistance value, tolerance and date code are

legend marked. The resistance values conform to IEC 62.

Solvent Resistance

The lacquer and protective sleeve provide excellent resistance

to all normal industrial cleaning solvents suitable for printed

circuits.

Matched Sets

Matched sets can be supplied for use as voltage dividers.

These may be screwed together to form sticks and, by

selecting the KU type of termination, a wire connection can

be provided at each end of the stick.

Enquiries are welcomed for special resistors and sets when

resistor length, operating voltage or resistance vale is outside

the catalogued range.

Packaging

All components are supplied in boxes.

Maximum

Typical

Load at rated power: 1000 hours at 20°C

∆R%

5

1

Shelf life: 12 months at room temperature

∆R%

0.5

Derating from rated power at 20°C

Zero at 100°C

Noise (µV/V in a decade of frequency)

<2.5

Voltage coefficient of resistance

ppm/V

<25

Performance Data

04.17

General Note

TT Electronics reserves the right to make changes in product specification without notice or liability.

All information is subject to TT Electronics’ own data and is considered accurate at time of going to print.

© TT Electronics plc

http://www.ttelectronics.com/resistors

BI Technologies IRC Welwyn