Mersen Open-Style Power Distri...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$446.69
Mersen Open-Style Power Distribution Block, UL 1953 1000V Tin-Plated Copper

Mersen Open-Style Power Distribution Block, UL 1953 1000V Tin-Plated Copper

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Model: MPDB66670

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

$446.69
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Mersen Open-Style Power Distribution Block, UL 1953 1000V Tin-Plated Copper

The Mersen Open-Style Power Distribution Block (PDB) is a next-generation adder block engineered to splice cables, split primary power into secondary circuits, and fulfill fixed junction tap-off requirements. Constructed with tin-plated copper connectors in a glass filled polycarbonate insulating body, this UL 1953 listed block is rated 1000V AC/DC and 310A, with a primary wire range of 350-#6 and a secondary wire range of #2-#14 across 1 primary opening and 4 secondary openings per pole. It meets spacing requirements for feeder and branch circuits per UL508A and the National Electrical Code®.

Key Features

  • Ampere Rating: 310A adder block rating for splitting primary power into multiple secondary circuits.
  • Voltage Rating: Rated 1000V AC and 1000V DC per UL, suitable for demanding power distribution applications.
  • Wire Range (Primary): Accepts 350-#6 conductors through a single box-type primary connector with a 0.75 in hole diameter.
  • Wire Range (Secondary): Accepts #2-#14 conductors across 4 box-type secondary openings per pole with a 0.31 in hole diameter.
  • Durable Construction: Tin-plated copper current-carrying connectors housed in a glass filled polycarbonate insulating body.
  • Short Circuit Ratings: 100 kA with Class J, T, RK1, RK5, L, and CC fuses, and 10 kA standalone, for robust fault protection.
  • Installation Mounting: Direct screw mount simplifies fixed junction tap-off installation.
  • Frequency: Rated for 50/60 Hz AC/DC operation.

Certifications & Compliance

  • UL 1953 Listed, 1000V AC/DC
  • Meets UL508A and National Electrical Code® spacing requirements
  • RoHS Compliant

Technical Specifications

  • Number of Openings per Pole (Secondary): 4
  • Number of Openings per Pole (Primary): 1
  • ROHS Compliant: Yes
  • Connector Type (Primary): Box
  • Connector Type (Secondary): Box

Typical Applications

  • Industrial and Commercial Power Distribution Panels
  • UL508A Industrial Control Panel Wiring
  • Splicing Cables and Fixed Junction Tap-Off Points
  • Splitting Primary Power into Secondary Circuits
  • Feeder and Branch Circuit Wiring per the National Electrical Code®

Why Mersen?

Mersen power distribution blocks combine tin-plated copper conductors with a glass filled polycarbonate insulating body to deliver a UL 1953 listed, 1000V, 310A-rated splicing solution built for code-compliant industrial and commercial electrical work. With short circuit ratings up to 100 kA across multiple fuse classes and RoHS compliant construction, this open-style PDB is engineered for reliable, safe performance in demanding power distribution applications.

Manufacturer Resources

Mersen Product Catalog

Product Specs

Hex Screw Size Type Secondary:
5/16-24 x .38
Hole Diameter Secondary:
0.31 in
Torque Rating Secondary:
#2-#3 50; #4-#6 35; #8 25; #10-#14 20
Rated voltage AC UL:
1000 V
Number Of Poles:
Adder
Ampere Rating Cu:
310 A
Short Circuit Rating (Class G):
100 kA with 60A Fuse
Installation Mounting:
Direct Screw Mount
Short Circuit Rating Class L:
100 kA with 400A Fuse
Hole Diameter Primary:
0.75 in
Short Circuit Rating Class T:
100 kA with 400A Fuse
Hex Screw Size Type Primary:
11/16-16 x .88
Number Of Openings Per Pole Secondary:
4
Short Circuit Rating (Class CC):
100 kA with 30A Fuse
Number Of Openings Per Pole Primary:
1
Wire Range Primary:
350-#6
Short Circuit Rating Class Rk5:
100 kA with 100A Fuse
ROHS Compliant:
Yes
Frequency (Hz):
50/60 Hz
Short Circuit Rating (Standalone):
10 kA
AC or DC:
AC/DC
Wire Range Secondary:
#2-#14
Short Circuit Rating Class J:
100 kA with 400A Fuse
Connector Type (Primary):
Box
Connector Material:
Tin-plated Copper
Rated voltage DC UL:
1000 V
Connector Type Secondary:
Box
Short Circuit Rating Class Rk1:
100 kA with 200A Fuse
Torque Rating Primary:
350-#6 275
Body/Insulating Material:
Glass Filled Polycarbonate
list_batch:
MERSEN-20260825
Department:
Electrical
Product Group:
Power Distribution
Product Type:
Power Distribution Block
Product Subgroup:
Power Distribution Blocks

Mersen MPDB66670 – Frequently Asked Questions

1) What wire sizes will the Mersen MPDB66670 power distribution block accept on the line and load sides?
The primary side takes 350 kcmil down to #6 through one box-type opening per pole with a 0.75 in hole, and each pole has four secondary box openings taking #2 down to #14 through a 0.31 in hole. If your tap conductors are larger than #2, this block will not land them.
2) Is the MPDB66670 a one-pole block or do I order one per phase?
It is an adder block, so it covers a single pole. For a three-phase feeder tap you stack three of them to get A, B and C. That is also how you build any pole count you need rather than being locked to a fixed 1, 2 or 3 pole body.
3) Can this Mersen distribution block be used at 1000V DC on a solar or battery system?
Yes. The block is UL rated 1000 V AC and 1000 V DC, and listed for AC/DC service at 50/60 Hz, so it suits PV combiner and DC bus work as well as 480/600V AC panels.
4) What short circuit current rating can I put on my UL508A panel label with this block?
Standalone the Mersen MPDB66670 is 10 kA. Protected upstream it goes to 100 kA, but the fuse size matters: Class J, T or L at 400A max, RK1 at 200A, RK5 at 100A, Class G at 60A, Class CC at 30A. Exceed the listed fuse amperage for that class and you lose the 100 kA number.
5) What torque do I set for the lugs on the Mersen MPDB66670?
Primary connector lands at 275 in-lb across the full 350-#6 range. Secondary varies by conductor: 50 for #2-#3, 35 for #4-#6, 25 for #8, and 20 for #10-#14. Hex sizes are 11/16-16 x .88 on the primary screw and 5/16-24 x .38 on the secondaries.
6) Is 310 amps the per-pole rating of this block?
310 A is the copper ampere rating for the adder block, so that is what one pole carries. Size the primary feeder and the branch taps so the total through the pole stays within it.
7) Does this Mersen block need a DIN rail or a separate mounting base?
No rail. The MPDB66670 is a direct screw mount block, so it fastens straight to the panel back-pan or sub-panel.
8) Open-style versus an enclosed power distribution block, which should I use?
Open-style, like this Mersen unit, leaves the connectors exposed, so it belongs inside an enclosure or control panel where the dead-front and spacing are handled by the enclosure. It meets UL508A and NEC spacing for feeder and branch circuits in that context. If the block will sit where people can reach energized parts, choose an enclosed or covered block instead.
9) How many branch circuits can I tap off one pole of the MPDB66670?
Four per pole. Each pole has one 350-#6 primary opening feeding four secondary openings sized #2-#14, so a single-phase pole gives you four tap-offs; three stacked poles give four per phase.
10) Are the connectors aluminum or copper, and will the body hold up in a hot panel?
Current-carrying parts are tin-plated copper, and the insulating body is glass filled polycarbonate. The block is also RoHS compliant, which matters for export and for institutional procurement specs.
How fast can I get the Mersen MPDB66670 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 Mersen MPDB66670 come with a warranty?
Absolutely. The Mersen MPDB66670 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 Mersen MPDB66670?
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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