FEATURES
+
Compatible with SA4102A / SA2002E / SA2002H /
SA2002P / SA2002D / SA2102D. All devices are PDIP20,
except for the SA2002P which is PDIP16.
+
Connection of external sensing elements, mains and
power supply by means of screw terminals.
+
Operation from either single +5V supply or dual rail supply
(20mA).
+
Direction and pulse output indication by means of on-board
LEDs.
sames
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PM4100APD Application Note:
Energy Meter Evaluation Module
PM4100APD
1/14
SPEC-1042 (REV. 3)
15-10-03
Figure 1: Functional Diagram
+
Current sensing via shunt or CT (on-board termination
resistor).
+
Counter and stepper counter connections by means of
screw terminals.
+
On-board precision calibration either by analog trimpot or
digital Eeprom.
+
Direct connection to micro-controller.
+
Optically isolated output for connection to test equipment.
+
Easy accessible test pins
INTRODUCTION
The PM4100AD evaluation module is designed to demonstrate
the functionality of the following devices SA4102A, SA2002E,
SA2002H, SA2002P, SA2002D and SA2102D. The module is
easily configured and setup for the various devices by means of
on-board jumpers. The setup of the module is simplified with the
help of the accompanying software that illustrates the jumper
positions for each device.
The measured energy is displayed on an on-board LED
(PULSE), while a stepper motor counter or impulse counter can
be connected to the screw terminals provided. A second LED
(DIR) is used to indicate the energy direction.
This application note should be used in conjunction with each
device's specific datasheet for the individual device
specifications and characteristics.
DEVICE
4N35
2
4
C
0
1
A
GND
IIN
IIP
STEPPER
COUNTER
PULSE
MICRO
PROGRAMER
LIVE
NEUTRAL
V
DD
GND
V
SS
DIR
PULSE
ANALOG INPUT
The most important external components for any SAMES
integrated circuit are the current and voltage sense resistors, as
well as the bias setting resistors. These resistors must be of the
same type as specified in the parts list to ensure that
temperature effects and noise susceptibility is minimized.
VOLTAGE INPUT IVP
The voltage input is driven with a current of 14A
RMS
(11A
RMS
to SA4102A) at the nominal rated mains voltage. Please note
that this input will saturate with currents bigger than
approximately 17A
RMS
, which translates into a 20% overdrive
capability. This also ensures that the device will not saturate
with a 10% variance in mains voltage. The main voltage is
divided down via a resistor network (see Figure 2) to 14V
RMS
.
This voltage is fed to a 1MW resistor (R8) to realize the
14A
RMS
.
The resistor values are chosen in such a way that shorting
jumper J2 leads to half the voltage on the voltage divider output.
This feature makes the module compatible for both 220V and
110V supply networks.
Ignoring jumper J2 results in the following equations:
RA = R5 + R6 + R7 + R10
RB = R8 || (R9 + 0.5P1)
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The center position of P1 is used in the equation to ensure that
calibration can be done by adjusting P1 to be higher or lower.
Combining the two equations gives:
(RA + RB)/220V = RB/14V
Values for resistors R9 = 12kW, P1 = 20kW and R8 = 1MW is
chosen.
Substituting the values result in:
RB = 26.29kW
RA = RB x (220V/14V-1)
RA = 386.84kW
Choosing standard resistor values for R5, R6, R7, R10 and
keeping in mind that J2 must half the output voltage leads to the
following values:
R5 = R7 = 82kW
R6 = R10 = 100kW.
Figure 2: Voltage divider circuit
RA
R5
R6
R7
R10
R8
R9
RB
P1
J2
NEUTRAL
LIVE IN
J26
C1
3/14
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PM4100APD
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CURRENT SENSE INPUT
Resistors R2 and R3 (figure 3 and figure 4) define the current
level into the current sense inputs of the device. The
PM4100APD module can be configured to use any type of
shunt or CT, but to ensure proper current sensing it is advisable
to use a shunt or CT that will give a voltage drop of at least 20mV
at maximum supply current. The resistor values are calculated
for an input of 16A
RMS
on the current sense inputs at rated
conditions. The design equation is as follows:
R2 = R3 = (I / 16A) x R
SH
/ 2 SHUNT Sensing
L
I
L
= Line current
R
SH
= Shunt value
Figure 4: Current sensing using a CT
Figure 3: Current sensing using a shunt
R2
R3
R1
C
T
O
N
L
Y
J1
CT
GND
1
2
3
CON2
CURRENT
IIN
IIP
R2
R3
GND
1
2
3
CON2
CURRENT
IIN
IIP
SENSING METHOD (CT OR SHUNT)
Provision is made for the use of either a Current Transformer
(CT) or a Shunt on the application module. For use with a CT,
the terminating resistor (R1) and phase compensation
capacitor (C1), as well as jumper (J1) must be inserted. The
jumper references one side of the CT to ground for sensing.
When using a CT the current sensing resistors (R2 and R3)
must be inserted according to the equation stated below.
R2 = R3 = (I /2500/16A) x R
1
/2 CT Sensing
L
I
L
= Line current
1:2500 = CT ratio
The capacitor C1 is inserted to compensate for the phase shift
caused by the current transformer. The following equation
shows how to calculate the capacitor value for a phase shift of
0.18 degrees.
C = 1 / (2 x p x Mains frequency x R8 x tan(Phase shift angle))
C = 1 / (2 x p x 50 x 1M x tan(0.18 degrees))
C = 1.013F
CTs with a low phase is recommended.
REFERENCE VOLTAGE
The on chip reference current is determined from a biasing
resistor R4 connected between pin 3 of the device and V
SS
.
This is 47kW for the SA2102D and SA4102A, and 24kW for the
rest of the devices compatible with this module.
ANALOG GROUND (GND)
The GND pin of the device is connected to the analog ground
plane, which is halfway between V
DD
and V
SS
.
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PM4100APD
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SETUP OF THE PM4100APD AS AN
ENERGY/POWER EVALUATION BOARD
The PM4100APD evaluation module comes with several
jumper selections, which allows the user to setup the module to
work for any of the devices mentioned. Tables 2 to 8 describe
the various jumper options. These tables should be used in
conjunction with figure 9, as well as the accompanying software
on disk (PM4100.exe) which will make it easier to locate the
jumper in question.
External connectors
The PM4100APD module connects directly to live and neutral
by means of a screw terminal (SCK1), and the current sensing
element is connected to CON2 as is shown in figures 5 and 6.
Connection diagram for CON3 and CON6 is shown in figures 7
and 8.
Programming the SA2002P must be done via an external
programmer/opto-isolator that connects to CON 3. There is
such a module available on request from SAMES, or a module
can be build as per information supplied in Figure 7.
Table 1 lists all the connectors available on the module.
Table 1: External connector descriptions
Figure 5: Current connection diagram for CT
Figure 6: Current connection diagram for Shunt
Figure 7: SA2002P Programming Connector
Figure 8: Micro Controller Connector
1
2
3
CON2
CURRENT
CT
LIVE IN
LIVE OUT
1
2
3
CON2
CURRENT
LIVE IN
LIVE OUT
Shunt
Shunt
V
D
D
V
S
S
S
C
L
S
D
A
L
E
D
R
L
O
A
D
1
2
3
4
5
6
7
CON3
PROGRAM
1
2
3
4
5
CON6
MICRO
V
D
D
F
M
O
F
_
_
O
U
T
D
I
R
O
V
S
S
Jumper Selection
The jumpers listed in table 2 is device independent and must
be setup according to the users needs.
Name
SK1
CON1
CON2
CON3
CON4
CON5
CON6
CON7
Description
Mains Connection
Power Supply
Sensing element connector
Programmer (SA2002P)
Stepper Motor Counter
Impulse Counter
Micro Controller
Opto-isolated Output Pulses
Table 2: Device independent jumpers
Name
Option
This jumper must be inserted when measurement
is done using a CT, and left open when using a
shunt.
This jumper must be inserted when working from
a 110V supply system, and left open when a
220V supply is used.
J1
J2
This jumper must be closed for regular use
Insert this jumper when using a shunt, and leave
open when using a CT.
J24
J26
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SA2002H (J6, J13, J15 to be used with Micro-controller)
Name
J6
J11
J12
J13
J14
J15
J25
State
B
B
B
B
A
A
A
SA2002E
Name
J11
J14
J25
State
B
A
A
SA2002P
Name
J4
J5
J6
J7
J8
J9
J10
J11
J12
J15
J22
J25
State
B
B
A
B
B
B
B
A
A
A
CLOSED
A
Table 3: Jumper options for SA2002P
Table 4: Jumper options for SA2002H
Table 5: Jumper options for SA2002E
SA2002D
Name
J7
J8
J9
J10
J11
J12
J13
J17,
J18,
J19
J20
J23
J25
State
A
A
A
A: Setting to A and J20 to + enables the FAST
output mode. Leaving J10 and J20 open
disables FAST mode and enables standard mode.
B
B
A
Rated conditions select (J17 for R0, J18 for R1,
J19 for R2). Please refer to the SA2002D datasheet
for further information. For Fast mode, any
combination except all to +. For different normal
mode settings, refer to the SA2002D datasheet.
Note: On module + = V
DD
and - = V
SS
"+" : FAST mode enabled.
"-" or OPEN: Standard mode enabled. Also see J10.
"-"
A
J4
J5
A
B
Bi-Directional Energy Measurement
Uni-Directional Energy Measurement
Forward
J3
J4
J5
Reverse
J3
J4
J5
+
A
A
-
A
A
Table 6: Jumper options for SA2002D
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