SA4301A
Rated Condition Select (RA, RB)
When FMS is floating the LED pin outputs fast mode pulses.
The motor pulses occur as usual based on the last FMS
before a floating condition was detected as well as the current
states of RA and RB. If a floating condition on FMS is
detected at device start-up the motor pulses are generated
The Rated Condition Select inputs (RA and RB) along with
the Fast Mode Select input (FMS) are used for obtaining a
multitude of meter constants and motor drive ratios. The
different LED and motor division factors (DF_LED and
DF_MO) that can be selected via RA, RB and FMS are shown
in Table 2.
based on FMS set to VSS
.
Table 2: LED and motor division factors
To calculate the LED output pulse constant in STANDARD
mode and the motor drive pulse constant for any meter rating
(IMAX and VNOM) the following formulae can be used:
FMS
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
RB
RA
DF_LED
146
292
584
1168
146
292
584
1168
146
292
584
1168
146
292
584
1168
976
1952
234
468
392
784
234
468
392
784
234
468
196
392
156
312
DF_MO
128
64
32
16
64
32
16
8
0
0
0
1
퐼푉푃
5000
1000 × 3600
0
Z
퐿퐸퐷 ꢀ푚푝/푘푊ℎ =
×
×
16 퐷퐹_퐿퐸퐷 3 × 푉ꢉ푂푀 × 퐼푀퐴푋
0
PH/DIR
...(1)
1
0
where
1
1
IMAX is maximum rated mains current,
VNOM is nominal mains voltage,
IVP is the analog input current on the voltage sense inputs at
VNOM as specified in Table 1 and
DF_LED is the dividing factor for the LED output that is set by
the combination of RA, RB and FMS as specified in Table 2.
1
Z
1
PH/DIR
Z
0
32
16
8
Z
1
Z
Z
Z
PH/DIR
4
Equation 1 is based on the assumption that the input currents
into the IIP/IIN current sense inputs are set to 16μARMS at
PH/DIR
0
16
8
IMAX
.
PH/DIR
1
PH/DIR
Z
4
퐿퐸퐷 ꢀ푚푝/푘푊ℎ
퐷퐹_ꢇꢊ
ꢇ표푡표푟 ꢀ푚푝/푘푊ℎ =
PH/DIR
PH/DIR
2
…(2)
0
0
32
16
32
16
16
8
where
0
1
LED imp/kWh is the LED constant as calculated using
Equation 1 and
DF_MO is the dividing factor for the motor output that is set
by the combination of RA, RB and FMS as specified in Table
2.
0
Z
0
PH/DIR
1
0
1
1
1
Z
16
8
Table 3 illustrates some of the possible LED and motor
constants that are achievable for some common values of
IMAX using a VNOM between 220V and 240V.
1
PH/DIR
Z
Z
0
8
1
4
Z
Z
8
Z
PH/DIR
4
PH/DIR
PH/DIR
PH/DIR
PH/DIR
0
8
1
Z
4
8
PH/DIR
4
Note:
Pin values defined as follows
0
1
Z
pin is connected to VSS
pin is connected to VDD
pin is left floating
PH/DIR pin is connected to PH/DIR
SPEC-1538 (REV. 7)
29-09-2017
10/23
SAMES [ SAMES ]
