24 Installation
●
Incorrect scale factors to convert from pulses to energy and power. This is commonly caused
by using the normal scale factors with an
Option P3
meter or selecting the wrong row of
column from the tables.
●
Some pulse counting equipment (data loggers, etc.) counts both rising and falling edges as
pulses, resulting in a count that is double the intended value. This can normally be corrected
by reconfiguring the device or dividing the scale factor by 2.0.
●
Some pulse monitoring devices cannot handle fast pulse rates. If the pulses occur too close
together, some may be missed by the monitoring device. Check the specifications of your
monitoring device or contact CCS support for assistance.
●
The CTs are not installed on the correct line phases. Verify that the CT phasing matches the
line Vac inputs.
●
The measured current exceeds the CT rating. This can saturate CT or the WattNode meter
input circuitry, resulting in lower than expected readings. If possible, use a current clamp to
measure the current and make sure it is below the CT rated amps.
●
The measured current is too small. Most current transformers are only specified to meet
their accuracy from 10% to 100% of rated current. In practice, most CTs work reasonably
well down to 1% of rated current. Very low currents may not register properly, resulting in low
power or no power reported.
●
Interference from a variable frequency or variable speed drive: VFD, VSD, inverter, or the
like. Generally, these drives should not interfere with the meter, but if they are in very close
proximity, or if the CT leads are long, interference can occur. Try moving the meter at least
three feet (one meter) away from any VFDs. Use short CT leads if possible.
NEVER
connect
the meter downstream of a VFD: the varying line frequency and extreme noise will cause
problems!
●
The CTs may be malfunctioning. If possible, use a current clamp to verify the current, then
use a DMM (multimeter) to measure the AC voltage between the white and black wires from
the CT (leave them connected to the meter during this test). At rated current, the CT output
voltage should equal 0.333 Vac (333 millivolts AC). At lower currents, the voltage should scale
linearly, so at 20% of rated current, the output voltage should be 0.20 * 0.333 = 0.0666 Vac
(66.6 millivolts AC).
●
The meter is not functioning correctly: if possible, swap the meter for another unit of the
same model.
