10
PT UNIT USER MANUAL
APRIL 2023 www.eaton.com.cn
3.5 Rotary Switches (PT10 only)
Up to 7 rotary switches can be found on the PT10/10G
trip unit’s front panel. These rotary switches set protection
settings using a surrounding legend indicating the value.
These are the core protection settings. Each switch has ten
positions and is set to achieve the appropriate trip-curve
characteristics. The “PICKUP” switches set the levels as a
function of the breaker ratings. The “TIME” switches set the
response in seconds. Each switch can be set using a small
screwdriver, the arrow pointing to the selected value.
Figure 9. PT10 Rotary Switch Area
3.6 Reset Button
The button labeled “RESET” can be depressed by using a
small tool. Press this button to reset the blinking cause of trip
indicator, clear locking alarm messages of the configurable
relays, and reset the “Check Mark” next to ZSI on the display
(lit on after the ZSI input signal is detected). (See Figure 5)
3.7 Door
Near the bottom of the PT unit, there is a small door with
the Universal Serial Bus (USB) icon. The door can be opened
downward to expose the micro-B USB port.
Figure 10. Trip Unit Door
3.8 USB
The USB is a micro-B USB connector utilizing USB 2.0
protocol. This USB connection may be used in conjunction
with the Power Trip Protection Manager software to configure
and monitor the trip unit. A USB connection will also typically
provide power from the host side of the USB cable to power
up the trip unit when another source of auxiliary power is not
available. This connection is intended for temporary use while
a user is configuring or monitoring the trip unit.
Trip Unit
Door
Figure 11. Behind the Trip Unit Door
3.9 Battery
At the bottom of the trip unit is a small tray which holds
the battery. When the trip unit is not powered, this battery
supplies power to cause-of-trip indicators and real-time clock
and assists the trip unit to record events. A battery icon at
the bottom of the display (PT20/25 only) indicates remaining
battery life. The battery life of the rotary switch type trip unit
(PT10) can be checked using a computer. The battery plays
no part in the protection functions of the trip system. This
battery is the standard type of CR 2032 coin-cell.
When used for the first time, the battery protection insulation
plastics needs to be manually removed to activate the
battery.
Figure 12. Battery Tray
3.10 In Ratings
This legend shows the In rating of the breaker. It is also
shown on the lower left corner of the display (PT20/25 style).
3.11 Side Labels
The side of the trip unit has agency certification, model, and
manufacturing information printed on a label.
Figure 13. Typical PT Trip Unit Side Label
USB Port
Battery Tray
Catalog No.
Style No.
Serial No.
Barcode(Serial No.)
Firmware Revision
Production Date Code
3. Power Trip (PT) Units
I
n
Rating
RESET Button
Rotary
switch
area
