Thermal-Magnetic Trip Unit Summary
Introduction
Thermal-magnetic trip units are designed to provide protection for distribution or for specific applications.
|
Identification |
Type of protection |
|---|---|
|
TM-D |
Thermal-magnetic trip unit |
|
TM-G |
Thermal-magnetic trip unit with low pickup (for protecting generators, very long feeds) |
|
MA |
Magnetic-only trip unit (for example, for protecting motors, transformers) |
The following table shows the trip units compatible with the ComPact NSX circuit breakers. For more information, refer to LVPED217032EN, ComPact NSX & NSXm Catalogue.
|
Trip units |
Built-in / Interchangeable |
NSX100 |
NSX160 |
NSX250 |
NSX400 |
NSX630 |
|||||
|---|---|---|---|---|---|---|---|---|---|---|---|
|
1P |
2P |
3P/4P |
1P |
2P |
3P/4P |
1P |
3P/4P |
3P/4P |
3P/4P |
||
|
NA (switch-disconnector) |
Built-in |
– |
– |
– |
– |
– |
– |
– |
– |
✔ |
✔ |
|
TM-D |
Built-in |
✔ |
✔ |
– |
✔ |
✔ |
– |
✔ |
– |
– |
– |
|
TM-D |
Interchangeable |
– |
– |
✔ |
– |
– |
✔ |
– |
– |
– |
– |
|
TM-AC |
Built-in |
– |
– |
– |
– |
– |
– |
– |
– |
✔ |
✔ |
|
TM-AC |
Interchangeable |
– |
– |
✔ |
– |
– |
✔ |
– |
✔ |
– |
– |
|
TM-G |
Interchangeable |
– |
– |
✔ |
– |
– |
✔ |
– |
✔ |
– |
– |
|
MA |
Interchangeable |
– |
– |
✔ |
– |
– |
✔ |
– |
✔ |
– |
– |
Protections and Settings of Thermal-Magnetic Trip Units
|
Item |
Parameter |
Description |
Type(1) |
||
|---|---|---|---|---|---|
|
TM-D |
TM-G |
MA |
|||
|
A |
– |
Trip unit setting range: minimum setting/maximum setting. Trip unit rating In corresponds to the maximum value of the setting range. |
O |
O |
O |
|
B |
Ir |
Thermal protection pickup |
✔ |
✔ |
– |
|
C |
tr |
Thermal protection time delay |
O |
O |
– |
|
D |
Ii |
Magnetic protection pickup |
✔/O |
O |
✔ |
|
E |
– |
Magnetic protection time delay |
O |
O |
O |
|
(1) Functions: ✔: Adjustable O: Non-adjustable ✔/O: Adjustable or non-adjustable according to the trip unit rating –: Not present |
|||||
Upgradeability of Thermal-Magnetic Trip Units
 WARNING |
|---|
|
HAZARD OF DESTRUCTION OF THE MICROLOGIC TRIP UNIT
It is mandatory to use snap-off screws LV429513 to install a MicroLogic trip unit.
Failure to follow these instructions can result in death, serious injury, or equipment
damage.
|
Upgradeability of trip units depends on the circuit breaker type:
-
For 1 or 2 poles, trip units are built-in.
-
For 3 or 4 poles, trip units are interchangeable.
Onsite swapping of trip units is simple and reliable:
-
No connections to make
-
No specific tools (for example, calibrated torque wrench)
-
Compatibility of trip units provided by mechanical cap
-
Torque limited screw provides proper mounting (see drawing below)
The design of the trip units limits the risk of incorrect tightening or oversights. The simplicity of the swapping process means that it is easy to make the necessary adjustments as operation and maintenance processes evolve.
