Schneider Electric 4000 DEMAND SYNCH PULSE INPUT

Chapter 5—Input/Output Capabilities 63230-300-212

Demand Synch Pulse Input April 2001

Youcan configure the circuit monitor to accept a demandsynch pulse from

an externalsource such as another demand meter. By accepting demand

synchpulses through a digital input, the circuit monitor can makeits demand

interval “window”match the other meter’sdemand interval “window.”The

circuit monitordoes this by “watch ing”the digital inputfor a pulse from the

other demandmeter. When it sees a pulse, it starts a new demand interval

and calculatesthe demand for the preceding interval. The circuit monitor

then uses the same timeinterval as the other meter for each demand

calculation.Figure 5–1 illustrates this point. See “SynchronizedDemand”on

page 59 in Chapter 4—Metering Capabilitiesfor more about demand

calculations.

When in demand synchpulse operating mode, the circuit monitor will not

startor stop a demand interval without a pulse. The maximumallowable time

betweenpulses is 60 minutes. If 66 minutes (110% of the demand interval)

pass before a synchpulse is received, the circuit monitor throws out the

demand calculationsand begins a new calculation when the next pulse is

received.Once in synch withthe billing meter, thecircuit monitor can be used

to verifypeak demand charges.

Important factsabout the circuit monitor’s demand synch featureare listed

below:

•Any installeddigital input can be set to accepta demand synch pulse.

•Eachsystem can choose whether to use an externalsynch pulse, but only

one demand synchpulse can be brought into the meter for each demand

system.One i nputcan be used to synchronize any combination of the

demand systems.

•The demandsynch feature can be set up from SMS. See the SMS online

help forinstructions on device set up of the circuit monitor.

Figure 5–1: Demand synch pulse timing

DEMAND SYNCH PULSE INPUT

Billing Meter

Demand Timing

Circuit Monitor

Demand Timing

Billing Meter

Demand Timing

Circuit Monitor

Demand Timing

(Slaved to Master)

Utility Meter

Synch Pulse