Milbank 100A 3-Phase Ringless ...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$1,718.14
Milbank U3771-XL-100 7 Terminal Ringless Meter Socket Small Closing Lever Bypass 1-100 Ampere Main Breaker

Milbank 100A 3-Phase Ringless Meter Socket with Main Breaker and Lever Bypass

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Model: U3771-XL-100

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

$1,718.14
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Milbank 100A 3-Phase Ringless Meter Socket with Main Breaker and Lever Bypass

Professional metering solution with integrated main breaker protection

The Milbank 100A 3-Phase Ringless Meter Socket delivers reliable electrical metering and main breaker protection for commercial and industrial applications. Featuring a robust G90 galvanized steel construction with powder coat finish and Type 3R rating, this UL Listed meter socket provides 100 continuous ampere capacity with integrated lever bypass functionality for safe maintenance operations.

Professional Features & Benefits

  • 100 Continuous Ampere Rating: Provides reliable power capacity for demanding commercial and light industrial electrical loads.
  • 3-Phase Configuration: Supports balanced three-phase power distribution for efficient motor and equipment operation.
  • Integrated Main Breaker: One 100 ampere main breaker delivers overcurrent protection and convenient disconnect capability.
  • Lever Bypass Provision: Enables safe meter maintenance and replacement without interrupting power to critical loads.
  • Type 3R Enclosure Rating: Weather-resistant construction suitable for outdoor installations and harsh environmental conditions.
  • G90 Galvanized Steel Construction: Durable material with powder coat finish ensures long-term corrosion resistance and structural integrity.
  • UL Listed Certification: Meets rigorous safety and performance standards for professional electrical installations.

Technical Specifications

  • Amperage Rating: 100 Continuous Ampere
  • Application: Meter Socket With Main
  • Brand Name: Milbank
  • Bypass Provision: Lever Bypass
  • Cable Entry: Overhead or Underground
  • Departent: Electrical
  • Equipment Ground: 3 Barrel Ground Lug
  • Frequency Rating: 60 Hertz
  • Hub Closing Plate: Small Closing Plate
  • Insulation: Glass Polyester
  • Line Side Wire Range: 6 - 2/0 AWG
  • Load Side Wire Range: 4 - 1/0 AWG
  • Main Breaker Size: One 100 Ampere Main Breaker
  • Number Of Jaws: 7 Terminal
  • Number Of Main Breakers: 1
  • Number Of Meter Positions: 1 Position
  • Number Of Receptacles: 0
  • Phase: 3 Phase
  • Product Family Code: MMMD
  • Product Height: 28 IN
  • Product Length: 4.844 IN
  • Product Material: G90 Galvanized Steel with Powder Coat Finish
  • Product Mounting: Surface Mount
  • Product Size: 4.844L x 13W x28H
  • Product Type: Ringless Meter Socket
  • Standard: UL Listed;Type 3R
  • Terminal: Lay in
  • Unspsc Number: 39121102
  • Voltage Rating: Up to 240 Volts Alternating Current
  • Width: 13 IN

Professional Applications

  • Commercial Buildings and Office Complexes
  • Light Industrial Facilities
  • Multi-Tenant Properties
  • Retail and Service Establishments
  • Municipal and Government Buildings
  • Educational Institutions
  • Healthcare Facilities

Why Choose Milbank Quality?

Milbank delivers proven reliability through UL Listed certification and Type 3R weather-resistant construction. The durable G90 galvanized steel with powder coat finish ensures long-term performance in demanding outdoor environments, while the integrated lever bypass system provides safe maintenance capabilities for uninterrupted service operations.

Manufacturer Resources

Product Specs

Amperage Rating:
100 Continuous Ampere
Application:
Meter Socket With Main
Brand Name:
Milbank
Bypass Provision:
Lever Bypass
Cable Entry:
Overhead or Underground
Equipment Ground:
3 Barrel Ground Lug
Frequency Rating:
60 Hertz
Hub Closing Plate:
Small Closing Plate
Insulation:
Glass Polyester
Line Side Wire Range:
6 - 2/0 AWG
Load Side Wire Range:
4 - 1/0 AWG
Main Breaker Size:
One 100 Ampere Main Breaker
Number Of Jaws:
7 Terminal
Number Of Main Breakers:
1
Number Of Meter Positions:
1 Position
Number Of Receptacles:
0
Phase:
3 Phase
Product Family Code:
MMMD
Product Height:
28 IN
Product Length:
4.844 IN
Product Size:
4.844L x 13W x28H
Product Type:
Ringless Meter Socket
Standards:
UL Listed;Type 3R
Terminal:
Lay in
Unspsc Number:
39121102
Voltage Rating:
Up to 240 Volts Alternating Current
Product Material:
G90 Galvanized Steel with Powder Coat Finish
Product Mounting:
Surface Mount
Amps:
100
Product Width:
13 IN
Department:
Electrical
Product Subgroup:
Electrical
Product Group:
Metering & Service Entrance

Milbank U3771-XL-100 – Frequently Asked Questions

1) Will the Milbank U3771-XL-100 meter socket work on a 3-phase 208Y/120 service?
The U3771-XL-100 is a 3-phase, 7 terminal (7 jaw) ringless socket rated up to 240 volts AC at 60 Hertz, so it covers the usual 3-phase 4-wire services in that range, including 208Y/120. Seven jaws is the standard jaw count for a 3-phase 4-wire self-contained meter. If your service is 480Y/277, this is the wrong socket, the voltage rating tops out at 240.
2) What size conductors can I land in the Milbank U3771-XL-100 meter socket?
Line side lugs take 6 AWG through 2/0 AWG and the load side takes 4 AWG through 1/0 AWG. Both are lay-in terminals, so you drop the conductor in rather than threading it through a hole. Grounding is a 3 barrel ground lug. At 100 amps that wire range is comfortable for copper and for the common aluminum sizes, but if your engineer has upsized the service conductors for voltage drop, check the actual conductor size against 2/0 before you order.
3) Can the Milbank U3771-XL-100 be mounted outdoors?
Type 3R and UL Listed, so it is built for outdoor wall mounting where rain and sleet are the exposure. The enclosure is G90 galvanized steel with a powder coat finish, and it is surface mount, meaning it hangs on the face of the wall rather than recessing into it. Type 3R is not a washdown or dust-tight rating, so a corrosive or hosed-down environment calls for a different enclosure type.
4) Do I still need a separate disconnect if I install the Milbank U3771-XL-100?
No separate service disconnect is needed at the socket. The U3771-XL-100 is a meter socket with main, carrying one 100 ampere main breaker built into the enclosure, so the metering and the service disconnect are in one can. That is the difference between this and a plain meter socket, which meters only and requires a disconnect downstream.
5) Will a ringless meter socket like the Milbank U3771-XL-100 pass my utility's inspection, or do they require a ring type?
The U3771-XL-100 is a ringless socket, meaning the cover slides over the meter and is sealed rather than a ring clamping the meter to the socket rim. Utilities specify one or the other and they are not interchangeable, so check your utility's approved meter equipment list before ordering. If they call for ring type, this socket will not be accepted no matter how the rest of the spec matches.
6) How much wall space do I need for the Milbank U3771-XL-100 meter socket?
The socket measures 4.844 x 13 x 28 inches, with a stated height of 28 inches and width of 13 inches. It surface mounts, so plan the full 28 inch height on the wall plus working clearance in front. The 4.844 inch depth is the projection off the wall face.
7) What does lever bypass mean on a meter socket, and do I need it?
Lever bypass on the U3771-XL-100 lets the utility or an electrician throw a lever that shunts current around the meter socket jaws, so the meter can be pulled and swapped without dropping power to the load. Many utilities require bypass on commercial services precisely so meter changes do not shut a tenant down. If your utility does not require bypass, a non-bypass socket is the simpler order, but bypass never hurts and is often specified on the drawing.
8) Can the Milbank U3771-XL-100 be fed from an underground service, or is it overhead only?
Both. Cable entry is overhead or underground, and it ships with a small closing plate for the hub opening. For an overhead drop you open the hub and fit the appropriate raintight hub for your conduit size; for an underground lateral you leave the closing plate in and bring conduit into the bottom. The hub itself is a separate item sized to your conduit.
9) Can I feed more than one tenant from the Milbank U3771-XL-100?
No. It is a single position socket with one meter and no auxiliary receptacles, so it serves one metered service only. A multi-tenant building needs a multi-position meter stack or a gang socket, one position per tenant, not this single can.
10) Is the Milbank U3771-XL-100 rated for continuous 100 amp load or is 100 amps the peak?
100 continuous ampere is the rating, so the socket and its 100 ampere main breaker are built to carry that load continuously rather than intermittently. Sizing for a continuous load still follows the usual code derating on the breaker itself, but the socket assembly is not the limiting factor at 100 amps.
11) What is the exact part number to order for a Milbank 100A 3-phase ringless socket with main breaker?
Order Milbank U3771-XL-100. That designation covers the 7 terminal ringless socket with small closing plate, lever bypass, and one 100 ampere main breaker. The 100 on the end is the main breaker size, so it is the digit to check if a drawing calls for a different main.
12) What insulation is used behind the jaws on the Milbank U3771-XL-100?
Glass polyester carries the jaw assembly. It is the standard insulating material for commercial meter sockets, dimensionally stable through outdoor temperature swings and non-tracking under the voltage this socket sees, which is why it holds up in a Type 3R enclosure exposed to weather.
How fast can I get the Milbank U3771-XL-100 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 U3771-XL-100 come with a warranty?
Absolutely. The Milbank U3771-XL-100 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 U3771-XL-100?
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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