SPEC-1654 (REV. 4)

8/18

29-09-2017

SA4104A / SA4104B

Reverse Energy Flow Indication

The SA4104A/B assesses the phase difference between the

voltage channel signal and the current channel signal. If this

phase difference is greater than 90 degrees then the DIRO

signal will become active. This facility is designed to detect

the wrongful connection of the meter. This operation is fully

described in the Output Signals section.

Starting Current

The SA4104A/B generates pulses on the LED and

MON/MOP outputs for an input power greater than 0.01% or

of the device is used. This is to comply with the IEC

requirement where the meter is required to generate pulses

for currents greater than 0.4%Ib.

Calibration and Repeatability

The SA4104A/B provides an output (LED) that is used for

calibration of the meter. The meter is calibrated by comparing

the energy reading of the meter under test with the energy

reading of the reference meter. The reference meter should

have a considerably higher pulse rate than the meter under

test. The accuracy to which the meter has to be calibrated will

dictate how much higher the reference meter pulse rate has

to be. The SA4104A/B can be calibrated to specification with

a minimum of two pulses on the LED output whilst in

STANDARD mode and utilizing an appropriate reference

meter. This reading is independent of time and will be

repeatable so as to consistently achieve the required

accuracy for the full input current range that needs to be

measured to IEC62053 accuracy. In Figure 6 the reference

meter pulses are counted between two pulses of the meter

under test. The meter under test is then adjusted so as to

reflect the expected number of counted reference meter

pulses. A worst-case scenario is for measurements obtained

for only two pulses of the meter under test and N pulses from

the reference meter. In this case the measurement resolution

will be:

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× 100

The corresponding calibration and repeatability results can

never be more accurate than this measurement resolution.

Power-On Reset

The SA4104A/B has a power-on reset circuitry that activates

whenever the voltage between VDD and VSS is less than

3.6V ± 8%.

Power Consumption

The power consumption of the SA4104A/B integrated circuit

is less than 30mW.

Figure 6: Calibration and repeatability setup

Reference

Meter

V

IN

N

I

IN

I

OUT

Single

Phase

Test

Source

Voltage

Neutral

Current

……….

……….

N pulses

Pulse Out

Meter Under

Test

SA4104A/B

V

IN

N

I

IN

I

OUT

LED