Phoenix Contact UT 4 Feed-Through Terminal Block, 32 A

UT 4: the 4 mm² workhorse of the UT range

The UT 4 is a single-level feed-through terminal block that joins one incoming conductor to one outgoing conductor through a screw clamp on each side. It is rated 1000 V and 32 A and is built for 4 mm² wire, although the clamp accepts anything from 0.14 mm² up to 6 mm², which gives wiring crews freedom to mix power and signal cores in one row.

Order number 3044102 is the grey standard version, supplied in a packing unit of 50 with no break packing. The type name reads simply: UT for the universal terminal family, 4 for the nominal cross section in mm². Seven Star LLC supplies the UT 4 in Oman and the GCC as an independent supplier in Muscat.

Technical specifications of the UT 4

How a UT 4 screw clamp carries current

Each side of the block has a captive screw that presses a conductor against a current bar inside the housing. The bar is a single metal part running from one clamp to the other, so the only resistance in the path is the two clamping points and the bar itself. This is why power dissipation at the rated current is only 1.02 W per block, a figure worth using when you calculate the heat load of a full terminal row.

The screw is M3 and is tightened to 0.6 to 0.8 Nm. Too little torque raises contact resistance and heats the joint; too much can damage fine strands. Following the stripping length of 9 mm and the A4 gauge size keeps the strands fully inside the clamp without leaving bare copper outside the housing.

Where the UT 4 fits in a terminal row

In a cabinet, the UT 4 forms the interface between field cables and internal wiring. Because its clamp window is generous, one block can take a 2.5 mm² feeder on one side and a 4 mm² jumper on the other. Where cross-connection is needed, standard plug-in bridges for the UT family can join neighbouring blocks, so a common supply can be shared across many outgoing circuits without extra wire.

The UT 4 sits between the smaller UT 2,5 used for signal circuits and the UT 6 and UT 10 used for heavier feeds. For protective earth, the matching UT 4-PE ground block with its green-yellow body replaces the grey feed-through block.

Selection and ordering checklist for the UT 4

• Wire size: 4 mm² nominal, 0.14 to 6 mm² accepted.
• Current: continuous load below 32 A per block, with derating for ambient temperature.
• Voltage: up to 1000 V in the stated overvoltage category III, pollution degree 3.
• Whether double-wire entry is needed (two conductors up to 1.5 mm² each).
• Rail: NS 35/7.5 or NS 35/15.
• Accessories: end covers, partition plates, bridges and marker strips to be ordered with the blocks.
• Quantity in multiples of the packing unit of 50 pieces.

Installation, commissioning and maintenance of the UT 4

Snap the block onto the rail, keep neighbouring blocks tight together, and close the row with an end clamp and an end cover. Strip 9 mm, insert the conductor fully, tighten the screw to the stated torque and give a light pull to prove the clamp. Where flexible cable is used, a ferrule up to 4 mm² avoids stray strands.

In service, retighten screws once after the first thermal cycles if your site practice requires it, and check for discoloured housings that point to an overloaded circuit. For measurements, use the test points of accessories rather than clamping probes onto live screws.

Typical applications in Oman and the GCC

In Oman and the GCC, the UT 4 appears in motor control centres, pump skids, compressor packages and substation marshalling cabinets where 2.5 to 4 mm² power wiring meets controls. High cabinet temperature under desert sun makes the 1.02 W dissipation figure useful for thermal checks, and the vibration-proof screw connection is suited to skid-mounted equipment that is transported and installed on site.

It is also common in water and desalination plants, where large numbers of identical circuits are wired in tidy rows and where maintenance staff prefer one familiar terminal for most circuits.

Comparison with neighbouring UT sizes

Information to send with an RFQ for the UT 4

• Full part number UT 4 and quantity in pieces (the page lists a packing unit of 50).
• Rail type and number of circuits per row.
• Wire sizes and any ferrule type.
• Requirement for bridges, covers and partition plates.

Documents and quotation

Send us the part number UT 4 and the quantity you need, and we will confirm which official documents are available for this item. Seven Star LLC is an independent supplier in Muscat and quotes for projects across Oman and the GCC; we do not act on behalf of the manufacturer.

Please also tell us the delivery location and the project timeline so that availability can be checked before you commit to a schedule.