Milbank 320A Ringless Meter So...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$669.19
Milbank U4778-X 320A Ringless Meter Socket with Lever Bypass and Barrel Lock Provision

Milbank 320A Ringless Meter Socket with Lever Bypass and Barrel Lock Provision

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Model: U4778-X-BL

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

$669.19
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Milbank 320A Ringless Meter Socket with Lever Bypass and Barrel Lock Provision

Professional Single-Phase Metering Solution with Advanced Security Features

The Milbank 320A Ringless Meter Socket delivers reliable single-phase electrical metering with integrated lever bypass functionality and barrel lock provision for enhanced security. Constructed with G90 galvanized steel and powder coat finish, this surface-mount meter socket provides 320 continuous ampere capacity with Type 3R enclosure rating for dependable outdoor performance. The unit features glass polyester insulation, dual barrel ground lugs, and accommodates overhead or underground cable entry configurations.

Professional Features & Benefits

  • 320 Continuous Ampere Rating: Handles high-capacity electrical loads for demanding residential and commercial applications with reliable performance.
  • Lever Bypass Provision: Enables safe meter maintenance and replacement without service interruption, reducing downtime and operational costs.
  • Barrel Lock Security: 9/16 inch knockout and angle bracket provision enhances meter security and prevents unauthorized access or tampering.
  • Type 3R Enclosure: Weather-resistant construction protects internal components from rain, sleet, and ice formation for reliable outdoor operation.
  • G90 Galvanized Steel Construction: Powder coat finish over galvanized steel provides superior corrosion resistance and long-term durability.
  • Flexible Cable Entry: Accommodates both overhead and underground service connections for versatile installation options.
  • UL Listed Compliance: Meets rigorous safety standards ensuring code compliance and professional installation confidence.

Technical Specifications

  • Amperage Rating: 320 Continuous Ampere
  • Application: Meter Socket
  • Barrel Lock Provision: 9/16 Inch Knockout and Angle Bracket for Barrel Lock Provision
  • Brand Name: Milbank
  • Bypass Provision: Lever Bypass
  • Cable Entry: Overhead or Underground
  • Departent: Electrical
  • Equipment Ground: 2 Barrel Ground Lug
  • Frequency Rating: 60 Hertz
  • Hub Closing Plate: Large Closing Plate
  • Insulation: Glass Polyester
  • Line Side Wire Range: 4 AWG - 600 kcmil or Two 1/0 AWG - 250 kcmil
  • Load Side Wire Range: Two 6 AWG - 350 kcmil
  • Main Breaker Size: No Main Breaker
  • Number Of Jaws: 4 Terminal
  • Number Of Main Breakers: 0
  • Number Of Meter Positions: 1 Position
  • Number Of Receptacles: 0
  • Phase: 1 Phase
  • Product Family Code: 4T32
  • Product Height: 38.75 IN
  • Product Length: 6.5 IN
  • Product Material: G90 Galvanized Steel with Powder Coat Finish
  • Product Mounting: Surface Mount
  • Product Size: 6.5L x 17.75W x38.75H
  • Product Type: Ringless Meter Socket
  • Special Features: Southern Maryland Electric Coop
  • Standard: UL Listed;Type 3R
  • Terminal: 3/8 Inch Stud
  • Unspsc Number: 39121102
  • Voltage Rating: 600 Volts Alternating Current
  • Width: 17.75 IN

Professional Applications

  • High-capacity residential service entrances requiring 320A metering capability
  • Commercial facilities with single-phase electrical distribution systems
  • Multi-unit properties requiring secure meter installations with bypass functionality
  • Professional offices and retail establishments with elevated power demands
  • Light industrial applications requiring weather-resistant outdoor metering
  • Emergency services facilities requiring reliable power monitoring and maintenance access

Why Choose Milbank Quality?

Milbank delivers proven reliability through UL Listed compliance and Type 3R weather-resistant construction. The G90 galvanized steel with powder coat finish ensures long-term durability, while the comprehensive wire range compatibility and dual ground lug configuration provide professional installation flexibility and safety assurance.

Manufacturer Resources

Product Specs

Amperage Rating:
320 Continuous Ampere
Application:
Meter Socket
Brand Name:
Milbank
Bypass Provision:
Lever Bypass
Cable Entry:
Overhead or Underground
Equipment Ground:
2 Barrel Ground Lug
Frequency Rating:
60 Hertz
Hub Closing Plate:
Large Closing Plate
Insulation:
Glass Polyester
Line Side Wire Range:
4 AWG - 600 kcmil or Two 1/0 AWG - 250 kcmil
Load Side Wire Range:
Two 6 AWG - 350 kcmil
Main Breaker Size:
No Main Breaker
Number Of Jaws:
4 Terminal
Number Of Main Breakers:
0
Number Of Meter Positions:
1 Position
Number Of Receptacles:
0
Phase:
1 Phase
Product Family Code:
4T32
Product Height:
38.75 IN
Product Length:
6.5 IN
Product Size:
6.5L x 17.75W x38.75H
Product Type:
Ringless Meter Socket
Special Features:
Southern Maryland Electric Coop
Standards:
UL Listed;Type 3R
Terminal:
3/8 Inch Stud
Unspsc Number:
39121102
Voltage Rating:
600 Volts Alternating Current
Product Material:
G90 Galvanized Steel with Powder Coat Finish
Product Mounting:
Surface Mount
Amps:
320
Product Width:
17.75 IN
Department:
Electrical
Product Subgroup:
Electrical
Insulation Type:
Glass Polyester
Hub Style:
Large Closing Plate
Installation Category:
Surface Mount
Terminal Type:
3/8 Inch Stud
Number of Phases:
1
Product Details:
Ringless Meter Socket
Frequency:
60 hertz
Number of Terminations:
4

Milbank U4778-X-BL – Frequently Asked Questions

1) What size service conductors will the Milbank U4778-X 320A socket lugs accept?
Line side terminals take 4 AWG through 600 kcmil, or a parallel pair of 1/0 AWG through 250 kcmil. Load side is dual, taking two conductors of 6 AWG through 350 kcmil, which is what lets a 320A service split into two 200A panels or a pair of feeders out of the socket. Both ground connections are barrel ground lugs, two of them.
2) Can the meter be pulled on a Milbank U4778-X without killing power to the building?
Yes, that is what the lever bypass is for. The U4778-X 320A socket has a lever bypass provision, so a utility tech or authorized electrician can shunt around the meter and swap or test it while the service stays live. Note the socket carries no main breaker, so the bypass is a metering maintenance feature, not a service disconnect.
3) What is the difference between the standard Milbank U4778-X-BL and the SMECO K3/K2 version?
Both are the same 320A ringless lever bypass socket. The U4778-X-BL is the standard build. The U4778-X-K3-K2-SMECO is built to the Southern Maryland Electric Cooperative utility specification. If your service is in SMECO territory, order the SMECO version, because a utility that specs its own configuration will reject a socket that does not match at inspection. Anywhere else, the standard U4778-X-BL is the one to buy.
4) Can the Milbank U4778-X 320A socket be mounted outdoors and fed from underground?
Outdoors is where it belongs. The enclosure is Type 3R rated and UL Listed, built from G90 galvanized steel with a powder coat finish for rain and ice exposure. Cable entry works either overhead or underground, so the same socket covers a mast riser or a lateral. A large hub closing plate is fitted at the top, which is what you remove or replace with a hub when you go overhead.
5) Does the Milbank U4778-X 320A meter socket come with a main breaker or a disconnect?
No. The U4778-X is a meter socket only, with zero main breakers and no receptacles. You still need a service disconnect, either a separate meter main or the main breakers in the panels it feeds. That is exactly why the load side is set up for two conductors of 6 AWG to 350 kcmil, which is the common 320A arrangement feeding two 200A panels.
6) Is a 4 jaw socket right for my service, or do I need a 5 jaw?
Four jaws is the single phase, 3 wire configuration, and that is what the U4778-X provides: 4 terminal, 1 phase, 600 volts AC. Standard residential and light commercial 120/240V single phase service uses 4 jaws. A 5 jaw socket is for network or 120/208V single phase service off a three phase system, and if the utility has specified 5 jaw, this socket will not accept the meter they intend to set.
7) Is a ringless meter socket the right choice, or do I need a ring type?
That call belongs to the serving utility, not the installer. The U4778-X is ringless, meaning the cover seals over the meter without a separate locking ring, and utilities that use ringless sockets seal the cover instead. Milbank builds both styles; if the utility spec sheet on your job calls for a ring type socket, this is the wrong part and you want a ringtype 320A lever bypass socket instead. The U4778-X also has a 9/16 inch knockout and angle bracket for a barrel lock, which is the security provision many co-ops require on ringless units.
8) How much wall space do I need for a Milbank 320A ringless meter socket?
The enclosure measures 6.5L x 17.75W x 38.75H inches. It is surface mount, so plan for that footprint plus working clearance in front of it, and remember the 38.75 inch height has to leave the meter face within the utility's required height window off finished grade.
9) What size lock fits the barrel lock provision on this Milbank socket, and what tools do I need to land the conductors?
The barrel lock provision is a 9/16 inch knockout with an angle bracket, which takes a standard utility barrel lock. Terminals are 3/8 inch studs, so bring the socket and torque wrench for 3/8 inch hardware. Internal insulation is glass polyester.
10) Can I use one Milbank U4778-X to meter two units in a duplex?
No. The U4778-X is a 1 position socket, one meter, one account. A duplex or any multi-unit property needing separate metering per tenant needs a multi-position meter stack or one socket per unit. Where the U4778-X does fit multi-family work is a single house meter or a 320A service feeding one owner account.
How fast can I get the Milbank U4778-X-BL 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 Milbank U4778-X-BL come with a warranty?
Absolutely. The Milbank U4778-X-BL 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 Milbank U4778-X-BL?
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
Why buy the Milbank U4778-X-BL from ZenSupply?
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