Specifications
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Doc. no.
Model
Apparatus
Scale
Page No
1SDH000460R0002
L5439
13.5.4.2. Neutral adjustment
The neutral protection is normally set to a current value 50% of the adjustment made on the phases.
In some installations, where particularly high harmonics occur, the current circulating on the neutral may be higher than that of
the phases.
In the SACE PR122/P release, this protection can be set for the following values:
I
n
N= 50% - 100% - 150% - 200% * I
n
.
13.5.4.2.1 Neutral adjustment specifications
Neutral (InN) adjustment must meet the following formula: I
1
x I
n
NIu.
In case of a four-pole CB, this setting is checked by the relay which signals any failure through a Led (see par. 13.6.1), and adjusts
the parameter independently to the accepted limits.
In case of a three-pole CB with external neutral, the relay performs no checks and user must correct the settings.
E.g.: With CB E1B800 with a 400A Rating Plug, Iu = 800A and I1 = 1In, I
n
N adjustment may be: 50-100-200%.
With CB E1B800 with a 800A Rating Plug, Iu = 800A and I1 = 1In I
n
N adjustment may be: 50-100%.
Note 1: I
1
=1I
n
setting is intended as the maximum adjustment of the protection against overloads. Actual maximum allowable adjustment must take into
account any temperature derating, terminals used and altitude, or In (rating plug)≤ 50% of circuit breaker size.
WARNING: Failure to comply with the setting limits for “I
1
” and “I
n
N” can cause circuit-breaker damage with
consequent risks even for the operator.
In any case, the relay records any setting error between I
1
and the Neutral setting and it signals this by means of the warning (see
par. 13.6.3). For four-pole CBs only.
13.5.4.3. Mains frequency settings
In the mains frequency menu, you can choose between the frequency values: 50, 60Hz.
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50 Hz
Main Frequency
Modules
Circuit Breaker
Settings
Password
Enter password
0***
1/2
4P
60 Hz
50 Hz
Mains Frequency
Enter
Enter
13.5.4.4. Modules
When you access the Settings menu, there is a set of menus available relating to the modules.
13.5.4.4.1 PR120/V MEASURING Module
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Optinal modules
COM module
SIGNALLING module
MEASURING module
Modules
Module configuration
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Absent
Rated voltage
Positive Power flow
Voltage Transf
MEASURING module
In the measuring module you must enter a password and can then opt for the absence or presence of the voltage transformer.
Moreover, you can select the values of the primary voltage (100, 115, 120, ... 1000V) and secondary voltage (100, 110, ... 230V).
The power flow can be LOW HIGH or HIGH LOW. After entering a password you can choose whether the neutral connection
is to be Absent or Present. For three-pole CBs only
13.5.4.4.2 PR120/D-M - COM module
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Communication parameters
COM module
SIGNALLING module
MEASURING module
Modules
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Local
Serial Address
Baudrate
Local / Remote
COM module
The local or remote modes can be selected after entering a password. The serial address can be displayed after entering a
password. The Baud Rate can be set on the values 9600 and 19200 bit/s. The physical protocol provides for the options: (8,E,1),
(8,0,1), (8,N,2), (8,N,1). The addressing can be selected as standard Modbus or ABB. For further information on the PR120/D-M
communication module, see paragraph 15.2 in this manual..
13.5.4.4.3 PR120/K - SIGNALLING module
For a thorough examination of the signalling module, refer to the corresponding section of the module, paragraph 15.3.
13.5.4.4.4 PR120/D - BT module
This module is for wireless communication based on the Bluetooth standard between the PR122/P protection release and a laptop
with a Bluetooth port. For further information, see the description of the module in paragraph 15.4.
13.5.4.4.5 Settings for the Local Bus unit
If the PR021/K unit is connected, you need to enable the local bus by selecting present.