Installation 23
Bad Line Frequency
If the meter detects a power line frequency below 45 Hz
or above 70 Hz, it will light all the LEDs yellow for at least
three seconds. The LEDs will stay yellow until the line
frequency returns to normal. During this time, the meter
should continue to accurately measure power. This can
occur in the presence of extremely high noise, such as if the meter is too close to an unfiltered
variable frequency drive.
Low Line Voltage
These LED patterns occur if the line voltage is too low
for the meter to operate correctly and the meter reboots
repeatedly. The pattern will be synchronized on all three
LEDs. Verify that the voltage on the Vac screw terminals is
not more than 20% lower than the nominal operating volt-
ages printed in the white rectangle on the front label. If the
voltages are in the normal range and the meter continues
to display one of these patterns, return it for service.
Measurement Troubleshooting
If the WattNode meter does not appear to be operating correctly or generating expected pulses,
start by checking the diagnostic LEDs as described in the previous section
. Then double check the installation instructions. If there are still problems,
check the following.
No Pulses
●
Make sure the load is turned on.
●
If the LEDs are flashing green, then the meter is measuring positive power and should output
pulses on
P1
, so there may be something wrong with the pulse output connection or you
may need a pull-up resistor; see
Connecting Pulse Outputs (p. 18)
●
If the LEDs on one or more phases are flashing red, then the total power may be negative,
in which case the meter won’t generate positive energy pulses. If you have a bidirectional
model, you can check for negative energy pulses on the
P2
output. If this is the case, check
that the line phases match the CT phases, that all the CTs face the source of power, and that
the CT white and black wires are connected correctly.
●
If all the LEDs are solid green (or off), then the measured power is below the creep limit
(1/1500th of full-scale) and the meter will not generate any pulses. See
●
If the LEDs are flashing green slowly, the power may be very low. A WattNode meter with a
nominal output frequency of 4.00 Hz can have a pulse period of several minutes at very low
power levels.
●
If all the LEDs are off, then the meter does not have sufficient line voltage to operate, or has
malfunctioned. Use a DMM (multimeter) to verify that the voltage on the Vac screw terminals
is within -20%, +15% of the nominal operating voltage.
Incorrect Power or Energy Readings.
This can be caused by any of the following:
●
An incorrect estimate of expected power or energy readings. If possible, try to verify the
actual energy, power, or current with a handheld power meter or current clamp.
3.0sec
C
B
A
Yellow
Yellow
Yellow
1.0sec
Y
Red
Y
Red
Y
Red
C
B
A
Y
Red
Y
Red
Y
Red
C
B
A
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
1.0sec
