User's Manual

Operation: C1SR Version
CENTRON Meter Technical Reference Guide 6-5
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 CENTRON C1SR Tamper Counter
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 ReadOne
®
Pro handheld reader converts the 4 bit binary number to
its equivalent value between 0 and 15. Table 6.1 shows the removal and inversion
information based on the reported tamper count. For example, a tamper count of 6
on the ReadOne Pro would translate as 1 meter removal and 2 meter inversions
since the last read.