Liebert EM User Manual

When using the OpenComms EM to monitor MP Advanced Power Strips, you may set thresholds that 

will trigger alerts for power, voltage, current and temperature sensors in each power strip.
Each sensor has four thresholds: High Critical, High Warning, Low Warning and Low Critical. The 

Normal range is determined by these limits. Table 9 shows examples of limits for these types of sen-

sors. Each level is color-coded in the Web interface for easy identification.

Using the examples of temperature sensor limits in Table 7, the following is a typical scenario:

• The temperature of a monitored area rises to 90°F. The status changes at two points:

• The status changes to High Warning when the temperature reaches 75°F. The serial port 

name, current reading and status are displayed in yellow text in the Web interface.

• As the temperature continues to rise, the status changes to High Critical at 85°F (displayed 

in red text). 

• At each change in status, the unit sends alerts if it is configured to do so. 

• When the temperature falls to 74°F, the status changes to Normal (displayed in green text) and a 

return-to-normal alert is sent if the unit is configured to send alerts.

• When the serial cable is disconnected from the unit, the status changes to Not Present (black 

text) and the serial port’s name appears in gray text.

High Critical

2400

132

20

85

Red

Red

Red

High Warning

1900

126

16

75

Yellow

Yellow

Yellow

Low Warning

1000

114

8

65

Yellow

Yellow

Yellow

Low Critical

500

108

4

60

Red

Red

Red

Other conditions
Normal

1 to 6999 115 to 125 0.1 to 19.9

66°F to 74°F

Green

Green

—

Not Present

(sensor is not connected)

Gray

Black

—