GE P24DM - DC Supply Monitor; DC Supply Monitor Implementation; Figure 130: DC Supply Monitor Zones

2 DC SUPPLY MONITOR
This product can be powered using either a DC or AC supply. As a DC supply is normally used, a DC Supply
Monitoring featur
e is included to indicate the DC supply status. The nominal DC Station supply is 48 V DC, which is
provided by a bank of batteries. It is sometimes possible for this nominal supply to fall below or rise above
acceptable operational limits. If the voltage is too high, it may indicate overcharging. If the voltage is too low, it
may indicate a failing battery.
In such cases it is very useful to have DC supply monitoring functionality. The P40 Agile products provide such
functionality by measuring the auxiliary DC supply fed into the device and processing this information using
settings to define certain limits. In addition, the DC Auxiliary Supply value can be displayed on the front panel LCD
to a resolution of 0.1 V DC. The measuring range is from 19 V DC to 300 V DC.
2.1 DC SUPPLY MONITOR IMPLEMENTATION
The P40Agile products provide three DC supply monitoring zones; zone 1, zone 2, and zone 3. This allows you to
hav
e multiple monitoring criteria. Each zone must be configured to correspond to either an overvoltage condition
or an undervoltage condition. A single zone cannot be configured to provide an alarm for both undervoltage and
overvoltage conditions. Typically, you would configure zones 1 and 2 for undervoltage conditions, whereby the
lowest limit is set very low, and zone 3 for an overvoltage condition whereby the upper limit is very high.
This is best illustrated diagrammatically:
V01221
Zone 2 (undervoltage)
Vdc nominal
Zone 1 (undervoltage)
Vdc2 lower limit
Vdc3 lower limit
Vdc1 upper limit
Vdc1 lower limit
Zone 3 (overvoltage)
Vdc3 upper limit
Vdc2 upper limit
Figure 130: DC Supply Monitor zones
It is possible to hav
e overlapping zones whereby zone 2 upper limit is lower than zone 1 lower limit in the above
example.
The DC Supply Monitoring function is implemented using settings in the DC SUP. MONITOR column. There are three
sets of settings; one for each of the zones. The settings allow you to:
● Enable or disable the function for each zone
● Set a lower voltage limit for each zone
● Set an upper voltage limit for each zone
● Set a time delay for each zone
Chapter 14 - Supervision P24xM
274 P24xM-TM-EN-2.1