Logic Beach
offers a variety of kW sensors to monitor and record AC power
demand from single-phase three-wire and three-phase three or
four wire electrical systems. Each sensor uses a split core
current transformer (CT) and voltage sensing leads to monitor
current and voltage which are used to calculate kilowatts. A
4 - 20mA output corresponds to a true RMS value. This mA output
is sampled by any of the analog inputs available on Logic Beach
data loggers and then converted to a kW value using a math function
available in our software. Logic Beach data loggers are expandable
and can monitor up to 44 kW sensors depending upon the data
logger model and configuration.
Using our software,
HyperWare, a user can write a program to integrate the demand
over time to provide consumption (kWh) on an hourly, weekly, monthly
time frame as well as total consumption. Hourly, weekly, and monthly
periods are typical examples, but the
4 -20mA demand signal can be integrated over a user-defined time
period as well. The flexibility of HyperWare will also let you
write a program to monitor just work days or specific time frames
as your application demands.
A sample application of this sensor is demonstrated
in predictive maintenance monitoring. This new plant discipline
is receiving more interest by many plant operators. Part of predictive
maintenance is understanding the historic operational data from
a particular plant system. As an example, the Department of Water
and Power in
Southern CA has some very large motors and pumps that are used
to pump water from the desert over the mountains to water treatment
plants around Los Angeles. If they were to monitor motor power
along with bearing temperatures and flow rates they could gain
an understanding of long-term motor and pump performance. Armed
with this data a prediction could be made when bearings need attention
or motors rebuilding in order to maximize output per kW consumed.
AC
Current and Power Selection Guide
