Blackburn WR739 AL HTYPE COMP CONN 397-266 4/0-1/0

The WR739 is sized for a 397 to 266 main run with a 4/0 to 1/0 tap. Both conductors go into the same H body and get crimped in one compression cycle, so it handles two conductors total. If your main is smaller than 266 or your tap is above 4/0, this is the wrong die size and you need a different H-tap in the range.

It is an aluminum H-tap. Aluminum bodies of this style are the standard choice for aluminum-to-aluminum splices and taps on secondary and service conductors. Use a connector rated for the metals in your specific job; if your run is copper, specify a copper-bodied H-tap in the same conductor range instead.

It is RUS Accepted and complies with ANSI C119.4, the standard covering connectors for use between aluminum and copper conductors. That is the reference most utility and electrical inspectors ask for on a compression tap, and RUS acceptance matters if you are working on rural utility funded distribution work.

It ships bare, with no insulation on the body. After crimping you cover it yourself, normally with a cold shrink or heat shrink tap cover, insulating tape build-up, or a molded H-tap cover sized to the finished crimp. Budget that cover into the job; it is not included.

Up to 90 degrees C. That lines up with 90 C rated conductor insulation such as XHHW-2 or USE-2, so the connector is not the limiting element on a typical 90 C secondary run. Ampacity still derates to whatever the conductor and termination rating allow.

The body is 2 inches long, plus the stripped conductor length and whatever insulating cover you put over it. In a tight secondary pedestal or J-box, allow for the crimp tool head to swing around the connector as well, since compression H-taps need the die closed square on the body.

Different install method, different tooling. The WR739 is a compression tap: it needs a hydraulic or battery crimper with the matching die, and once crimped it is permanent and vibration proof with no torque to re-check. A mechanical split-bolt goes on with wrenches and can be taken apart, but it depends on maintained torque. For direct buried or utility secondary work where nothing gets re-tightened later, crews specify the compression H-tap.

It is sold each, so quantity ordered equals connectors received. Count one per tap point and add spares, since a compression H-tap is a one-shot connection and a bad crimp means cutting it off and starting over.

Mexico. That matters on jobs with country-of-origin reporting requirements or domestic preference clauses, so check your project spec before submitting it.