ITRON Centron, Technical Reference Manual

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Operation: C1SR Version
32 CENTRON® Meter Technical Reference Guide
Tamper Detection
The CENTRON C1SR features the Itron patented method of tamper detection that senses
both meter removal and meter inversion. The removal tamper (RTPR) increments a counter
each time the meter is abruptly removed from a live meter socket. The tamper counter
utilizes a tilt switch to detect when the meter is removed from a meter socket.
The inversion tamper (ITPR) increments a separate counter each time the meter senses
reverse power flow caused by meter inversion. The metrology board senses reverse power
flow and sends this status to the C1SR module. Although the C1SR increments an inversion
counter when reverse power flow is detected, the meter, when undetented, will still
accumulate the energy consumption in the positive direction. Each of these tamper
indications, along with the kWh consumption, is then transmitted through the radio
frequency transmission.
Testing the C1SR Tamper Counter
SCM Testing
In order to test the power removal counter, the meter must sense a shaken condition
associated with a power outage.
1
Place the meter in a socket.
2
Apply power to the meter.
3 Remove the meter from the live socket.
4
Replace the meter in the socket.
The meter has incremented the removal tamper counter.
The C1SR uses the power outage (the meter being removed from a live socket) in
conjunction with the meter being shaken simultaneously to increment the power removal
counter.
In order to test the inversion counter, the meter must sense reverse current flow.
1 Place the meter in the meter socket inverted (test LED pointing down).
2 Apply a load to the meter in the forward direction.
The meter has incremented the inversion counter due to reverse energy flow through the
meter.
The inversion counter increments when the meter senses reverse current flow. The
metrology board senses reverse power flow and sends this status to the C1SR personality
module. The C1SR then increments the counter and transmits the count.
As part of the 96-bit Standard Consumption Message, 4 bits are allocated for tamper
indications, which include the power removal and meter inversion counters. The table below
shows the removal and inversion information based on the reported tamper count.