Schneider Electric PM810, PM870 Demand Synch Pulse Input, Relay Output Operating Modes, Normal

PowerLogicTM Series 800 Power Meter	63230-500-225A2
Chapter 5—Input/Output Capabilities	3/2011

Demand Synch Pulse Input

You can configure the power meter to accept a demand synch pulse from an external source, such as another demand meter. By accepting demand synch pulses through a digital input, the power meter can make its demand interval “window” match the other meter’s demand interval “window.” The power meter does this by “watching” the digital input for a pulse from the other demand meter. When it sees a pulse, it starts a new demand interval and calculates the demand for the preceding interval. The power meter then uses the same time interval as the other meter for each demand calculation. Figure 5–2illustrates this option. See “Demand Readings” on page 30 in Chapter 4—Metering Capabilities for more about demand calculations.

When in demand synch pulse operating mode, the power meter will not start or stop a demand interval without a pulse. The maximum allowable time between pulses is 60 minutes. If 66 minutes (110% of the demand interval) pass before a synch pulse is received, the power meter throws out the demand calculations and begins a new calculation when the next pulse is received. Once in synch with the billing meter, the power meter can be used to verify peak demand charges.

Important facts about the power meter’s demand synch feature are listed below:

•Any installed digital input can be set to accept a demand synch pulse.

•Each system can choose whether to use an external synch pulse, but only one demand synch pulse can be brought into the meter for each demand system. One input can be used to synchronize any combination of the demand systems.

•The demand synch feature can be set up using PowerLogic software.

Figure 5–2: Demand synch pulse timing

PLSD110140

Normal Demand Mode		External Synch Pulse Demand Timing
	Billing Meter		Billing Meter
	Demand Timing		Demand Timing
		Utility Meter
		Synch Pulse
	Power Meter		Power Meter
			Demand Timing
	Demand Timing
			(Slave to Master)

Relay Output Operating Modes

The relay output defaults to external control, but you can choose whether the relay is set to external or internal control:

•External (remote) control—the relay is controlled either from a PC using PowerLogic software or a programmable logic controller using commands via communications.

•Power meter alarm (internal) control—the relay is controlled by the power meter in response to a set-point controlled alarm condition, or as a pulse initiator output. Once you’ve set up a relay for power meter control, you can no longer operate the relay remotely. However, you can temporarily override the relay, using PowerLogic software.

NOTE: If any basic setup parameters or I/O setup parameters are modified, all relay outputs will be de-energized.

The 11 relay operating modes are as follows:

•Normal

—Externally Controlled: Energize the relay by issuing a command from a remote PC or programmable controller. The relay remains energized until a command to de- energize is issued from the remote PC or programmable controller, or until the

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