User's Manual

Testing, Troubleshooting, and Maintenance
8-2 CENTRON Meter Technical Reference Guide
LED will flash once for every 10Wh infrared pulses received. The left LED on the
pulse detector is helpful when heavier loads are present on the system being
examined. This can be used to verify that the metrology is measuring energy when
installed and to conduct timing tests to determine the amount of load on meter. See
Chapter 9 for the Pulse Detector part number.
Figure 8.2 Pulse Detector
Annunciators
Watthour Annunciators
C1SR meters (and some C1S versions) are equipped with LCD displays that utilize
a single flashing triangular annunciator to show that power is being metered. The
annunciator represents 1.0 watthour each time it turns on and 1.0 watthour each
time it turns off for a total of 2.0 watthours.
On other CENTRON meters equipped with LCD’s, there are 3 such annunciators
which also show the direction of energy flow (C1S, C1SC, C1SD, C1ST, C1SL). The
triangles will scroll left to right for positive (line to load) energy flow, and right to
left for negative energy flow.
The Kh value of the single triangle is twice the Kh of the LED and, therefore, 2.0
watthours per pulse. On the three triangle units the Kh of each triangle is further
multiplied by 3 as each triangle is turned on and off in sequence, resulting on a Kh
of 6.0.
TOU Rate Annunciators
The CENTRON meter is equipped with 5 Time-of-Use annunciators on the LCD
(see Figure 8.3). Located on the right side of the display, the annunciator A, B, C, D,
or TOTAL flashes when the applicable rate is active and is enabled to display their
respective values. (Available on the C1ST and C1SL.)