Table of Contents
Advertisement
When the PT20/25 trip unit is initially powered-up, the
display will briefly show a loading screen and then change
to the "Main" menu. During this time, the trip unit is already
functioning and performing protection operations. Depending
on the trip unit style, there are up to 14 submenu selections
from the main menu. Each submenu can be accessed by
highlighting the appropriate submenu by pressing the Down
or Up Arrow buttons, then the Enter button.
3.3 Password Protection Functionality
The cybersecurity of your system is critical. The PT electronic
trip unit has a four-digit password for protection. To change
non-rotary switch settings, the password is required. When
the change takes longer than 10 seconds, the authorization
will time out. When wrong password is entered three times,
there will be a ten-minute lockout period, during which
access will be prohibited.
There are two levels of password: "Administrator" and
"User". The factory default is the administrator level, and
the password is "0000". If needed, the administrator can
create a user and decide whether that user can change the
protection settings. Password security is enforced when
changing settings over network communication using the
LCD, PTM software, and other devices. The password can
only be provided to those who need it. Changing the default
password is key for comprehensive network security policy
when the PT is installed or configured. The password is four-
digit length, with numeric characters from 0 to 9.
For PT20/25 electronic trip unit, settings are password
protected to reduce the risk of unauthorized changes to the
settings. The correct password ("0000" by factory default)
must be entered in the "Edit Settings" menu to change the
following settings:
•
Language
•
Communication configuration (for on-board Modbus)
•
Thermal memory
•
Power settings
•
System voltage setting
•
Usage frequency setting
•
Circuit breaker early warning setting
•
User management
•
System time setting
•
Relay setting
•
Neutral pickup (100%, 60%, off)
•
ZSI - Zone Selective Interlock (on or off)
•
Edit password
•
Long/short time delay protection settings
•
Instantaneous protection settings
•
Ground protection settings
•
Over-voltage/under-voltage protection settings
•
Voltage/current unbalance protection settings
•
Reverse power protection settings
•
Over-frequency/under-frequency protection settings
•
Phase sequence protection settings
•
Power/current demand protection settings
•
Phase loss protection settings
•
The PT10 password protection function is set by the
PTM, and the thermal memory function can be enabled
or disabled by writing the password in the PTM.
3.4 Pickup/Cause-of-Trip Indicators
There are four pickup/cause-of-trip indicators on the face of
the trip unit labeled "LONG", "SHORT", "INST", and "GND".
Figure 8. Pickup/Cause-of-Trip Indicators
Pickup/
Cause-
of-trip
indicator
RESET button
The appropriate cause-of-trip indicator illuminates when a
current level pickup setting is exceeded. After a trip event,
the indicator blinks (one second on, three seconds off) and
the cause will be shown on the display if auxiliary power is
applied. The indicators and the display can be cleared by
pressing the RESET button.
Following is a list of conditions detected and displayed by the
cause-of-trip indicators.
•
"LONG" – Blinking indicates a Long Delay trip or over
temperature trip has occurred.
•
"SHORT" – Short Delay trip or mechanism error.
•
"INST" – Instantaneous trip, Making Current Release
(MCR) trip, High Instantaneous trip has occurred.
•
"GND" – Ground trip or Ground alarm condition has
occurred.
PT UNIT USER MANUAL APRIL 2023 www.eaton.com.cn
3. Power Trip (PT) Units
Pickup/
Cause-
of-trip
indicator
RESET button
9
Advertisement
Table of Contents
