Allen-Bradley 825-PR12D Manual page 8

8 825-P Motor Relay Application
825-P Motor Relay Application
The 825-P Motor Relay provides comprehensive motor protection, including short
circuit, load loss, load jam, and frequent starting protection, as well as unbalance
current and phase reversal protection. The 825-P uses the overload protection element
to accurately track the heating effects of overloads and unbalance current.
Combining the 825-PR12D and the 825-P enhances this list of protection features by
adding remote RTD-based thermal protection.
Up to 12 RTD inputs
Motor
Figure 1 Motor Protection with the 825-P Motor Relay
Step 1.
Step 2.
825-PR12D RTD Scanner
Load
Connect the 825-PR12D to the 825-P Motor Relay using a
62.5/125 μm fiber-optic cable with ST connectors between the
825-PR12D fiber-optic TX output and the 825-P fiber-optic input
labeled RX RTD MODULE.
The 825-P and 825-PR12D use 820 nm rated, ST connector-based,
fiber-optic ports.
Set the 825-P to accept the RTD temperature data packets (see Data
Packet Definition on page 11) sent by the 825-PR12D:
You can use any of the following two methods to enter the settings:
➢
Relay front-panel menus:
.
Settings
➢
Personal computer connected to the relay front serial port,
using a terminal emulation software package and ASCII
commands.
a. In the 825-P, set the RTD ENABLE (E49RTD) equal to Y.
This enables use of the 825-PR12D data.
b. Set the RTD Location and RTD Type settings based on the
information you recorded in Table 1.
c. Finally, set the RTD Alarm and Trip Temperature settings as
required for your application.
Refer to the 825 User Manual 825-UM004_-EN-P for more details
regarding calculation and entry of these settings.
Fiber-Optic Ports
(built into 825-PR12D & 825-P)
825-PR12D
Up to 500 meters via
single fiber-optic cable
Set/Show > RELAY > RTD
825-P
Relay
Date Code 20080722