MPA3 V6.3 MOTOR PROTECTION RELAY MANUAL
Issue: R0, Date: 11/2010, CRN: 8168
MPAB010 Rev0
MPA3 V6.2 Motor Protection Relay Manual
Page 17
The RTD temperatures for group 1 and group 2 can be viewed on the ‘Temperature Information’ Page, Level 2,
Positions 1 and 2 respectively. The measurement range is 0°C to 210°C. Values greater than 210°C represent an
error condition as follows:
Error
Comment
246
Error code 246 results if the RTD terminals are left
open circuit or the RTD resistance rises above 330
.
Unused RTD inputs can be terminated with a 100
resistor (0
C) to avoid the error code.
245
Error code 245 results if the RTD is short-circuited or
its resistance falls below 80
.
The RTD’s will operate correctly if the combined installation cable resistance to the PT-100 RTD is less than 40
.
12
Analogue Output
The optional Monitoring Module (MPA-M) provides an isolated analogue output configurable as 0-20 mA or 4-20 mA.
The output is selected via the ‘
An OP
:’ setting (Level 7, Position 24) to continuously monitor one of the following
sections:
Trip Accumulator
(20 mA = 100%)
Average Current
(20 mA = 1000%)
Earth Leakage
(20 mA = 100%)
RTD Temp (0-200 °C)
(20 mA = 200°C)
Current Balance
(20 mA = 100%)
Phase Voltage (A phase)
(20 mA = 120%)
The analogue output status is shown on the ‘MPA I/O Status Information’ Page, Level 5, Position 4. The value
shown for ‘
Analog Out
’ is related to the analogue output current according to:
I
out (mA) = Displayed Value x 8.1458 x 10
-05
13
Communications
When the MPA is ordered with an optional monitoring module a communications port is provided. This allows for the
connection of the MPA to PLC or SCADA systems. Two different monitoring modules are available providing a
choice between RS485 Modbus RTU and EtherNet/IP.
With either communications option, the same data is available over the network. See Section 23, ‘
’ for accessible data.