Fused Terminal Blocks Selection Guide: Technical Criteria & Application Standards
Fused Terminal Blocks selection guide: technical parameters, mounting and compliance standards, and Onka comparison.
A fused terminal block is a DIN rail terminal block that protects the circuit it connects to with a glass fuse inserted in the fuse holder in its housing, and isolates the line when the fuse is removed. It is used in control panels to protect each of the small-current branches, such as sensors, PLC inputs and outputs, pilot lights and measuring circuits, individually. In this category, Onka MRK-S series 6 mm² screw-connection and OPK-S series 2.5 mm² spring-connection fused terminal blocks are listed with 6.3 A rated current, in housing colors such as beige, gray, blue, red, yellow and black. Choose the connection type (screw or spring) to match the other terminal blocks in the panel, the housing (2.5 mm² or 6 mm²) by conductor cross-section, the glass fuse's rated current by the circuit to be protected and the housing color by circuit grouping. The manufacturer describes these models as without glass fuse; the rated current of the separately supplied fuse must not exceed the terminal block's 6.3 A. A fused terminal block does not replace the miniature circuit breaker used for line protection; when the glass fuse blows, it is replaced with a new one. The Fused Terminal Blocks category on Welibaba includes 16 active models from leading manufacturers such as Onka.
Key Technical Parameters for Selecting Fused Terminal Blocks
To specify the right Fused Terminal Blocks model for your panel or installation, verify the following parameters against your engineering schedule:
| Parameter | Typical Catalog Values | Verification Note |
|---|---|---|
| Current | 6.3 A | Verify against project schedule and load calculation |
| Voltage | 750 V | Verify against project schedule and load calculation |
| Cross-Section Type | 2.5 mm, 6 mm | Verify against project schedule and load calculation |
| Color | Bej, Gri, Kahverengi, Kırmızı | 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 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 Barrier Terminal Blocks, Junction Box Terminal Blocks, Terminal Block Accessories and Spares.
Frequently Asked Questions
What is the first parameter to check when selecting Fused Terminal Blocks?
Start by confirming the circuit's rated electrical values and physical mounting dimensions, then use the technical attribute filters on the Fused Terminal Blocks page to narrow down compatible series.
Which Fused 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 Fused 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.