Tap-Off Terminal Blocks Selection Guide: Technical Criteria & Application Standards
Tap-Off Terminal Blocks selection guide: technical parameters, mounting and compliance standards, and Onka comparison.
A tap-off terminal block is a complementary terminal block used with a large-cross-section DIN rail terminal block to take a smaller-cross-section branch conductor from the main line. It is used in power distribution panels to take a measuring, control or auxiliary circuit supply from feed terminal blocks, without cutting the main conductor or adding a separate distribution block. In this category, the two types made for Onka MRK series 35-50 mm² and 70-95-120 mm² terminal block groups are listed with 76 A rated current and 750 V rated voltage, in beige, gray, brown, red, blue, yellow, black and green. Choose the tap-off terminal block first by the cross-section group of the main terminal block it will be fitted to (35-50 mm² or 70-95-120 mm²); compare the branch line's current with the 76 A rated current and the branch conductor's cross-section with the connection cross-section in the manufacturer data, and match the housing color to the main terminal block. A tap-off terminal block is not a feed-through terminal block used on its own; it works together with a compatible main terminal block, and protection of the branch line is determined separately in the project. The Tap-Off Terminal Blocks category on Welibaba includes 16 active models from leading manufacturers such as Onka.
Key Technical Parameters for Selecting Tap-Off Terminal Blocks
To specify the right Tap-Off Terminal Blocks model for your panel or installation, verify the following parameters against your engineering schedule:
| Parameter | Typical Catalog Values | Verification Note |
|---|---|---|
| Current | 76 A | Verify against project schedule and load calculation |
| Voltage | 750 V | Verify against project schedule and load calculation |
| Number of Levels | Standart | Verify against project schedule and load calculation |
| Cross-Section Type | 50 mm, 70-95-120mm | Verify against project schedule and load calculation |
Installation, Compatibility, and Commissioning Checklist
- Electrical & Mechanical Matching: Confirm that rated voltage, current capacity, and mounting dimensions align with the upstream and downstream components in DIN Rail Terminal Blocks.
- Environmental & Enclosure Rating: Check IP protection class, housing material, and terminal capacity for dusty, humid, or high-vibration industrial environments.
- Related Product Groups: If your application calls for a different form factor or rating, compare sibling categories such as 1-In 2-Out Terminal Blocks, 2-In 2-Out Terminal Blocks, 2-In 2-Out Test Terminal Blocks.
Frequently Asked Questions
What is the first parameter to check when selecting Tap-Off Terminal Blocks?
Start by confirming the circuit's rated electrical values and physical mounting dimensions, then use the technical attribute filters on the Tap-Off Terminal Blocks page to narrow down compatible series.
Which Tap-Off Terminal Blocks brands are available on Welibaba?
Welibaba currently stocks 16 active models in this category from manufacturers including Onka, complete with verified specifications and unit pricing.
How can I compare Tap-Off Terminal Blocks models by manufacturer part number?
You can search directly by manufacturer SKU/order code or use the category filter panel to compare equivalent models across brands side by side.