Burndy BISR250DB Unitap Direct...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$18.57
Burndy BISR250DB Unitap Direct Burial Insulated Splice Reducer

Burndy BISR250DB Unitap Direct Burial Insulated Splice Reducer

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Model: BISR2

In Stock (leaves warehouse same day if ordered before 3pm ET)

$18.57
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Burndy BISR250DB Unitap Direct Burial Insulated Splice Reducer, Aluminum

The Burndy BISR250DB is a Unitap series direct burial, insulated in-line splice/reducer for 4/0 AWG-250 kcmil conductors. Dual rated for aluminum and copper, this two-port connector ships with an oxide inhibitor pre-installed for below-grade corrosion protection. It carries a 600V minimum voltage rating and is UL Listed to UL468A-468B for underground splicing work.

Key Features

  • Conductor Range: 4/0 AWG-250 kcmil, dual rated for aluminum and copper conductors.
  • Durable Construction: Aluminum body and hardware for corrosion-resistant performance.
  • Direct Burial Rated: Engineered for direct burial installation in underground splice applications.
  • Insulation: Plastisol insulation with an oxide inhibitor pre-installed against corrosion.
  • 2-Port In-Line Design: Two-port design secured with 2 screws, 5/8 screw size, 5/16 hex key, 360 installation torque.
  • Voltage Rating: 600V minimum voltage rating for underground electrical connections.
  • Finish: Unplated aluminum hardware and connector body.

Certifications & Compliance

  • UL Listed
  • Complies with Industry Standard UL468A-468B
  • RoHS Compliant

Technical Specifications

  • Ports: 2
  • Product Material: Aluminum
  • Plating: Unplated
  • Series: Unitap
  • UL Listed: Y
  • UPC: 781810288061
  • Width (in): 1.18
  • Insulation Type: Plastisol
  • Type of Plating: Unplated
  • CULUS: N
  • Number of Ports: 2
  • Length (in): 6.70
  • Type of Hardware: Aluminum
  • Product Description: In-Line Splice/Reducer, 2 Port, 4/0 AWG-250 kcmil, Al/Cu Rated
  • Aluminum Size (Range): 4/0-250 kcmil
  • Number of Screws: 2
  • Plated (Yes or No): N
  • Industry Standards: UL468A-468B
  • Screw Size: 5/8
  • CSA Certified: N
  • UL Recognized: N
  • Rated for Direct Burial: Y
  • Copper Solid Size (Range): N/A
  • Installation Torque: 360
  • Min Voltage Rating: 600
  • Hex Size (Key): 5/16
  • Height (in): 2.17
  • ROHS Compatible: Compliant
  • Conductor - AL Str Size Range: 4/0 AWG - 250 kcmil
  • Conductor - Copper Str Size Range: 4/0 AWG - 250 kcmil
  • Trade Name: UNITAP™

Typical Applications

  • Direct-Burial Underground Splice Connections
  • Underground Distribution and Service Entrance Wiring
  • Utility and Industrial Power Distribution Systems
  • Substation and Switchgear Conductor Connections
  • Below-Grade Electrical Installations

Why Burndy?

Burndy's Unitap BISR250DB pairs an aluminum body with a pre-installed oxide inhibitor and Plastisol insulation for long-term underground reliability. Its UL468A-468B listing and 600V rating support code-compliant splicing on 4/0 AWG-250 kcmil aluminum and copper conductors.

Manufacturer Resources

Spec Sheet

Product Specs

Wire Size:
4/0 AWG
Ports:
2
Plating:
Unplated
Series:
Unitap
UL Listed:
Y
UPC:
781810288061
Width (in):
1.18
Insulation Type:
Plastisol
Type of Plating:
Unplated
CULUS:
N
Number of Ports:
2
Length (in):
6.70
Type Of Hardware:
Aluminum
Copper Stranded (Range):
4/0 AWG-250 kcmil
Aluminum Size (Range):
4/0-250 kcmil
Number of Screws:
2
Plated (Yes or No):
N
Industry Standard(s):
UL468A-468B
Screw Size:
5/8
CSA Certified:
N
Ul Recognized:
N
Rated for Direct Burial:
Y
Installation Torque:
360
Min Voltage Rating:
600
Hex Size (Key):
5/16
Height (in):
2.17
ROHS Compatible:
Compliant
Connector Type:
In-Line
Conductor - AL Str Size Range:
4/0 AWG - 250 kcmil
Conductor - Copper Str Size Range:
4/0 AWG - 250 kcmil
Product Type:
Splice Reducer
Trade Name:
UNITAP™
Product Material:
Aluminum
list_batch:
BUR-20260916
Department:
Electrical
Product Subgroup:
Wire Connectors
Product Group:
Wire Connectors & Terminals

Burndy BISR2 – Frequently Asked Questions

1) Can the Burndy BISR250DB Unitap splice reducer be buried directly in the ground without a splice box?
Yes. The BISR250DB is rated for direct burial, which is what separates it from the plain BISR250. The Plastisol insulation seals the connection and an oxide inhibitor comes pre-installed inside the barrel for below-grade corrosion protection, so no separate enclosure or resin kit is needed for an underground splice.
2) What conductor sizes will the BISR250DB accept, and does it take both aluminum and copper?
It is dual rated Al/Cu and takes stranded 4/0 AWG through 250 kcmil in either metal. Both the aluminum and copper stranded ranges are the same, 4/0 AWG to 250 kcmil, so you can splice aluminum to copper in the same connector. Solid copper is not part of the rated range.
3) What size hex key and what torque do I need to install a Burndy Unitap BISR250DB?
A 5/16 inch hex key drives the setscrews, and each screw torques to 360 inch-pounds. Screw size is 5/8. Bring a torque wrench with a 5/16 hex bit; hand-tightening a direct burial splice at this size is how you get a hot connection underground.
4) Is the BISR250DB UL Listed for underground splicing, and what voltage can I use it at?
UL Listed, to UL468A-468B, and rated 600V minimum. That covers underground service entrance and distribution splicing at 600V and below. It is not CSA certified and not marked cULus, so for Canadian work you would need a CSA certified connector instead.
5) My conductors are 350 kcmil, not 250. Is there another Burndy BISR that fits?
The BISR250DB tops out at 250 kcmil, so 350 kcmil will not seat. Burndy builds the same in-line Unitap splice in other conductor sizes, including BISR-350 for 350 kcmil and BISR-500 for 500 kcmil, plus BISR2 for 2 AWG and BISR-1/0 for 1/0 AWG on the smaller end. Confirm the direct burial rating on whichever size you pick, since that rating is what the DB suffix on the 250 denotes.
6) Is this a straight splice or does it reduce between two different conductor sizes?
It is an in-line, two-port splice reducer, so it joins one conductor to another end to end and the two do not have to be the same size as long as both fall inside 4/0 AWG to 250 kcmil. Two setscrews, one per port. If you need to tap a run rather than splice it end to end, an in-line body is the wrong shape for that.
7) How much room do I need in the trench or handhole for this splice?
The insulated body measures 6.70 by 2.17 by 1.18 inches, so allow roughly seven inches of straight conductor plus bending room for the hex driver to clear the setscrews. That footprint fits most handholes but is worth checking against a tight pull box before you commit.
8) The body is unplated aluminum. Will that corrode on a copper conductor?
Both the connector body and the hardware are aluminum, unplated, and the barrel ships with oxide inhibitor already loaded, which is what handles the dissimilar metal contact when you land copper in it. That is why the connector is Al/Cu dual rated rather than aluminum only. Do not wipe the inhibitor out when you clean the conductor.
9) Do I still need to tape or heat-shrink over this splice underground?
No separate insulation is required. The Unitap in-line splice comes insulated with a Plastisol cover as part of the connector and is rated for direct burial as supplied, so it is a single-piece install: strip, insert, torque both setscrews to 360 inch-pounds, backfill.
10) Is the Burndy Unitap BISR250DB RoHS compliant for a spec-driven project?
Yes, it is listed as RoHS compliant, and it carries the UL Listing to UL468A-468B. For submittal packages the manufacturer spec sheet is published by Hubbell for this exact catalog number.
How fast can I get the Burndy BISR2 delivered?
Most orders ship the same day from our distribution partners, with quick delivery throughout the continental U.S. Need it urgently? Contact Us for expedited shipping options.
Can I return it if it doesn’t work for me?
Yes—ZenSupply offers a hassle-free return policy. If the product isn’t the right fit, reach out to our support team for a return authorization or setup a return by following our return instructions.
Does the Burndy BISR2 come with a warranty?
Absolutely. The Burndy BISR2 is backed by a manufacturer’s warranty. For full warranty terms, check the product documentation or Contact Us.
How do I get technical support or installation help for the Burndy BISR2?
You can call, text, or email our expert support team for fast answers. We’re here to help with product selection, installation tips, and troubleshooting. Contact Us
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