13.2.2 Power supply characteristics
Symbol
Hardware modules
+
-
PSM3.1
PSM3.2
EIM3.1
GAM3.2
DU 300
The power supply is connected to these terminals.
CAUTION
The frame ground is connected to the power supply terminals through transient voltage suppression diodes (commonly
known as transorbs). In order to protect the frame ground and power supply, no more than 36 V allowed across the frame
ground and the power supply terminals.
Backup power
The DEIF equipment does not contain a backup power supply. The power supply source must therefore include the power backup
needed.
Start current
When the power supply is connected, the start current may briefly exceed the current that corresponds to the maximum power on
the data sheet.
Battery-powered systems normally do not have a problem with start current.
For other types of power supply, for example, an AC-to-DC supply, the start current may be a problem. The minimum rating for the
power supply current limiter is therefore included on the data sheet.
Reverse polarity
The power supply is protected against reverse polarity. That is, if the power supply terminals are switched, the DEIF equipment will
not be damaged. However, the DEIF equipment will not be able to operate until the power supply has been connected correctly.
Diode compensation
Diode compensation is available in PSM3.1, PSM3.2, EIM3.1 and GAM3.2. Set the parameter under
Configure > Parameters >
Hardware > [PSM3.1 1, PSM3.2 1, EIM3.1 1 or GAM3.2 1] > Diode compensation
.
Parameter
Range
Default Notes
Diode offset 0 to 1 V DC 0 V DC
This corrects the power supply measurement values used for the supply voltage alarms. Use
this to compensate for a small decrease in voltage over the diode.
DESIGNER'S HANDBOOK 4189340911K UK
Page 413 of 521