Technical Specifications

For SR Surge Resistors with Surge Energy Rating 660J - 1.8 kJ:

RESISTOR

TYPE

DIM.

CODE

OVERALL

DIMENSIONS

VOL.

MAX.

J

MAX.

W

T.T.C.

WT.

A/L

RESISTANCE RANGE

Do

Max

Lo

Max

Lp

Pitch

(v)

   

@25˚C

  

@25˚C

 

(t)

  

  

MIN

  

MAX

UNITS

 

(mm)

(mm)

(mm)

(cm3)

(J)

(W)

(s)

(g)

(cm)

(Ohms)

(Ohms)

SR 0775

1911

21

15

11 - 12

3.1

775

3.00

260

9.0

2.6

3R9

1K8

SR 1000

1914

21

18

14 - 15

4.0

1000

3.50

285

10.5

2.0

5R6

2K7

SR 1200

1917

21

21

17 - 18

4.8

1200

3.75

320

13.0

1.7

6R8

3K3

SR 1425

1920

21

24

20 - 21

5.7

1425

4.25

335

15.0

1.4

8R2

3K9

SR 1775

1925

21

29

25 - 26

7.1

1775

5.00

355

18.0

1.1

10R0

4K7

NOTES

Vol (v) = Volume of Active Material (cm3)

T. T. C. = Thermal Time Constant (t)  (Seconds)


Maximum Working Voltages (V working)

The Maximum Working Voltage levels  can be derived from the appropriate formulae illustrated in the tables below. Examples are shown at the foot of this page.

Waveforms are defined in the usual manner: 1.2 / 50 s indicates a rise time to peak value in 1.2 s and an exponential decay to half amplitude in a total time of 50 s.

SR 0775

 

IMPULSE / WAVESHAPE

MAX. WORKING VOLTAGE (kV)

(50 Hz rms)

1.0 x ( 2.6R / t ) 0.3

(1.2 / 50 s)

0.79R x (  -1 + √ ( 1 + 23 / R ) )

(10 / 1000 s)

0.0393R x ( -1 + √ ( 1 + 462 / R ) )

(500 / 5000 s)

0.0079R x ( -1 + √ ( 1 + 2308 / R ) )


SR 1000

 

IMPULSE / WAVESHAPE

MAX. WORKING VOLTAGE (kV)

(50 Hz rms)

1.3 x ( 2.0R / t ) 0.3

(1.2 / 50 s)

0.79R x ( -1 + √ ( 1 + 29 / R ) )

(10 / 1000 s)

0.0393R x ( -1 + √ ( 1 + 588 / R ) )

(500 / 5000 s)

0.0079R x ( -1 + √ ( 1 + 2938 / R ) )


SR 1200

 

IMPULSE / WAVESHAPE

MAX. WORKING VOLTAGE (kV)

(50 Hz rms)

1.6 x ( 1.7R / t ) 0.3

(1.2 / 50 s)

0.79R x ( -1 + √ ( 1 + 36 / R ) )

(10 / 1000 s)

0.0393R x ( -1 + √ ( 1 + 714 / R ) )

(500 / 5000 s)

0.0079R x ( -1 + √ ( 1 + 3568 / R ) )


SR 1425

 

IMPULSE / WAVESHAPE

MAX. WORKING VOLTAGE (kV)

(50 Hz rms)

1.9 x ( 1.4R / t ) 0.3

(1.2 / 50 s)

0.79R x ( -1 + √ ( 1 + 42 / R ) )

(10 / 1000 s)

0.0393R x ( -1 + √ ( 1 + 839 / R ) )

(500 / 5000 s)

0.0079R x ( -1 + √ ( 1 + 4197 / R ) )


SR 1775

 

IMPULSE / WAVESHAPE

MAX. WORKING VOLTAGE (kV)

(50 Hz rms)

2.4 x ( 1.1R / t ) 0.3

(1.2 / 50 s)

0.79R x ( -1 + √ ( 1 + 52 / R ) )

(10 / 1000 s)

0.0393R x ( -1 + √ ( 1 + 1049 / R ) )

(500 / 5000 s)

0.0079R x ( -1 + √ ( 1 + 5246 / R ) )


 

Worked example (50 Hz rms) :

Consider an SR 1200 Resistor with a Resistance Value of 100R0.

What is the maximum 50 Hz rms Working Voltage (kV) sustainable for an insertion time of 100 ms?

V working = 1.6 x (1.7R / t) 0.3 = 1.88 kV

(Note: R = Resistance Value in Ohms and t = 50 Hz Insertion time in ms)

 

Worked example (10 / 1000 s) :

Consider an SR 1200 Resistor with a Resistance Value of 100R0.

What is the maximum Working Voltage (kV) for a 10 / 1000 s waveform?

V working = 0.0393R x (-1 + √(1 + 714 / R)) = 7.28 kV

 
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
                     
Home  |  Site Map  |  About HVR  |  Products  |  Applications  |  Agents  |  Contact Us  |  Events
   Copyright HVR International Limited 2015. All Rights Reserved. This page last updated: 17 April, 2013.