Schneider Electric 4000 per pulse per hour per second, watt-hours x 3600 seconds x pulse watts =

Chapter 4—Metering Capabilities 63230-300-212

Demand Readings April 2001

The circuitmonitor has ten input pulse metering channels. The channels

count pulsesreceived from one or more digital inputs assigned to that

channel. Eachchannel requires a consumption pulse weight, consumption

scale factor,demand pulse weight, and demand scale factor.The

consumptionpulse weight is the number of watt-hours or kilowatt-hoursper

pulse.The consumption scale factor is a factor of 10 multiplier that

determines the formatof the value. For example,if each incoming pulse

represents125 Wh, and you want consumption data in watt-hours, the

consumptionpulse weight is 125 and the consumption scale factor is zero.

Theresulting calculation is125 x 100, which equals 125 watt-hoursper pulse.

If you wantthe consumption data in kilowatt-hours, the calculationis 125 x

10-3, which equals 0.125kilowatt-hours per pulse.

Timemust be taken into account for demand data so youbegin by calculating

demand pulseweight using the following formula:

If each incomingpulse represents 125 Wh, using the formula above you get

450,000watts. If you want demand data in watts, the demand pulse weight

is 450 and the demand scalefactor is three. The calculation is 450 x 103,

which equals450,000 watts. If you want the demand data in kilowatts,the

calculationis 450 x 100, which equals 450 kilowatts.

The circuitmonitor counts each input transition as a pulse. Therefore,for an

inputtransition of OFF-to-ON and ON-to-OFF will be countedas two pulses.

Foreach channel, the circuit monitor maintains the following information:

•Totalc onsumption

•Last completedi ntervaldemand—calculated demand for the last

completedinterval.

•Partiali ntervaldemand—demand calculation up to the present point

during the interval.

•Peakdemand—highest demand value since the last reset of the input

pulse demand. The dateand time of the peak demand is also saved.

•Minimumdemand—lowest demand value since the last reset of the input

pulse demand. The dateand time of the minimum demand is also saved.

Forexample, you can use channels to verify utility charges.In Figure 4–6,

Channel 1 is addingdemand from two utility feeders to track total

consumptionand demand for the building. Thisinformation could be viewed

in SMS and comparedagainst the utility charges.

Touse the channels feature,first set up the digital inputs from thedisplay or

from SMS.See“SettingUpI/Os”on page 23 in Chapter 3—Operation for

instructions.Then using SMS,you must set the I/O operating mode to Normal

and set up the channels.The demand method and interval that you select

appliesto all channels. See theSMS online help for instructionson device set

up of the CM4000Circuit Monitor.

Input Pulse Demand Metering

per pulse per hour per second watt-hours x 3600 seconds x pulsewatts =