ABB TF42-29 Thermal Overload Relay
The TF42-29 is a 24–29A thermal overload relay providing economic electromechanical protection for motor main circuits against overload and phase failure. Designed to mount directly onto compatible ABB AF-series contactors, it offers trip class 10 performance with temperature compensation, making it a dependable choice for motor control panels in UAE industrial and commercial installations.
Key Features
- 24–29A adjustable setting range for accurate protection matched to motor full-load current
- Trip class 10 with temperature-compensated bimetallic tripping for reliable performance across ambient conditions
- Selectable automatic or manual reset with trip-free mechanism and clear trip indication
- Integrated STOP function for straightforward manual isolation during maintenance
- Genuine ABB quality — direct mounting compatibility with ABB AF09 through AF38 contactors
Technical Specifications
| Specification |
Details |
| Brand |
ABB |
| Model |
TF42-29 |
| Rated Operational Current (Ie) |
29A |
| Setting Range |
24-29A |
| Poles |
3P |
| Trip Class |
10 |
| Rated Operational Voltage |
690V AC / 600V DC |
| Auxiliary Contacts |
1 NC + 1 NO |
| Degree of Protection |
IP20 |
| Suitable For |
ABB AF09, AF12, AF16, AF26, AF30, AF38 Contactors |
| Ambient Operating Temperature |
-25°C to +60°C |
Applications
- Motor overload and phase failure protection in HVAC and pump control panels
- Direct-on-line and star-delta motor starter assemblies in industrial facilities
- Panel builds requiring compact, contactor-mounted thermal protection
- Retrofit protection upgrades for existing ABB AF-series contactor installations
FAQ
-
What does this relay protect?
It provides overload and phase-failure protection for the motor circuit it's fitted to, tripping the associated contactor if the current draw exceeds the set threshold for too long.
-
Does this mount directly onto a contactor?
Check the Technical Specifications table for the specific compatible contactor range — many ABB thermal overload relays mount directly onto a matching contactor without separate wiring for the current path.
-
What is trip class 10?
Trip class defines how long the relay allows an overload before tripping at a given multiple of the set current — class 10 is a standard general-purpose setting suited to most motor applications (as opposed to class 20/30 used for high-inertia loads with longer start times).
-
Can I install this myself?
No. This is a motor control panel component and should be installed and set by a licensed electrician or panel builder.
