Data Sheet AS8118

Revision 1.8, 15-Feb-05

Page 9 of 30

Anti-Creep Threshold Setting

The anti-creep threshold is programmable to ensure that the set threshold lies between the anti-creep current, a current level

at which no pulses must be generated and the start current. The programmable threshold levels have been set to

connection is through a current transformer. The formulae for calculating the appropriate thresholds are as follows:

Shunt:

5

1

5

1

1000

4

*

I

*

I

*

th

_

ac

Start

B

=

=

Current Transformer:

5

1

5

1

1000

2

*

I

*

I

*

th

_

ac

Start

B

=

=

Parameter: Acreep_sel

(All values are given in mA, unless otherwise specified)

Setting

Shunt

Shunt

CT

CT

2.3

1.5

6

9

1.2

6

0.6

3

00

2.3

2.5

10

15

2

10

1

5

01

7.4

5

20

30

4

20

2

10

14.8

10

40

60

8

40

4

20

10

14.8

15

60

90

12

60

6

30

29.7

20

80

120

16

80

8

40

11

29.7

30

120

n/a

20

100

10

50

The default Anti-Creep threshold (ac_th) is set at 7.4mA, best suited to a 30A (IB*6) or 20A (IB*4) meter. The default Anti-

Creep is the programmed threshold setting, without any programming required to the AS8118.

Summary of Programmable Parameters

The AS8118 programming options, along with the default settings have been summarised in the table below:

I Gain

CAL

MON/MOP

LED

Anti-Creep Threshold

20

8

100

100

2.32mA

16

16

200

200

7.43mA

432

400

400

14.90mA

64

800

800

29.70mA

1600

3200

6400

Note: The default settings have been highlighted.