Schneider Electric PM820 User Manual

© 2011 Schneider Electric. All Rights Reserved.

This section describes the advanced alarm features found on the PM850 and the PM870. 
For information about basic alarm features, see “Basic Alarms” on page 45.

In addition to the basic alarm groups (see “Basic Alarm Groups” on page 45), the 
following advanced alarm groups are available.

•

Boolean—Boolean alarms use Boolean logic to combine up to four enabled alarms. 
You can choose from the Boolean logic operands: AND

, 

NAND

, 

OR

, 

NOR, or XOR to 

combine your alarms. Up to 10 alarms can be set up in this group. 

•

Disturbance (PM870)—Disturbance alarms have a detection rate of half a cycle and 
are useful for detecting voltage sags and swells. The Power Meter comes configured 
with 12 default voltage sag and swell alarms; current sag and swell alarms are available 
by configuring custom alarms. Up to 12 disturbance alarms can be set up in this group. 
For more information about disturbance monitoring, see Chapter 9—Disturbance 
Monitoring (PM870)  on page 65.

•

Custom—The power meter has many pre-defined alarms, but you can also set up your 
own custom alarms using PowerLogic software. For example, you may need to alarm 
on a sag condition for current A. To create this type of custom alarm: 
1. Select the appropriate alarm group (Disturbance in this case).
2. Delete any of the default alarms you are not using from the disturbance alarms 

group (for example, Sag Vbc). The Add button should be available now.

3. Click Add, then select Disturbance, Sag, and Current A.
4. Give the alarm a name.
5. Save the custom alarm.

After creating a custom alarm, you can configure it by applying priorities, setting pickups 
and dropouts (if applicable), and so forth.

PowerLogic software can be used to configure any of the advanced alarm types, but the 
power meter display cannot be used. Also, use PowerLogic software to delete an alarm 
and create a new alarm for evaluating other metered quantities.

Boolean alarms

10

10

Disturbance alarms

—

12

Alarm levels

Yes

Yes

Custom alarms

Yes

Yes