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RACO 189SM 4 in. Welded Square Steel Box
The RACO 189SM is a 4 in. welded square steel outlet box, 1-1/2 in. deep, engineered for conduit wiring systems. It features ten 1/2 in. knockouts and six 1/2 - 3/4 in. combination (TKO) knockouts for flexible conduit entry, a raised ground provision, and a factory-installed 10 inch #12 stranded copper grounding pigtail. This UL Listed box is built for reliable, code-compliant electrical installations in commercial and industrial applications.
Key Features
- Trade Size: 4 in. square box, 1-1/2 in. deep, sized for standard conduit wiring systems.
- Durable Construction: Welded steel body forms a rigid, one-piece enclosure built to withstand jobsite handling and long-term service.
- Knockouts: Ten 1/2 in. and six 1/2 - 3/4 in. combination (TKO) knockouts allow flexible conduit sizing and multiple entry points.
- Raised Ground: Raised ground stamping provides a dedicated location for secure equipment grounding connections.
- Grounding Pigtail: Pre-installed 10 inch #12 stranded copper pigtail simplifies grounding termination in the field.
- No Bracket: Ships without a mounting bracket for direct, conduit-supported installation in Conduit wiring systems.
Certifications & Compliance
- UL Listed
Technical Specifications
- Product Type: Steel Box
- Product Size: 4 in
- Product Depth: 1.5 in
- Product Shape: Square
- Drawn or Welded: Welded
- Bracket Type: No Bracket
- Wiring System: Conduit
- Knockouts: 1/2 in;1/2 - 3/4 in Combination (TKO)
- Certified Listed: UL Listed
Typical Applications
- Commercial and Industrial Electrical Installations
- Conduit and Raceway Systems
- Device and Outlet Box for Switches and Receptacles
- New Construction and Renovation Wiring
Why RACO?
RACO steel boxes are welded for a rugged, one-piece enclosure and include practical, field-ready details like raised ground stamping and a pre-installed copper pigtail to speed up grounding terminations. Backed by a UL Listing, the RACO 189SM delivers dependable, code-compliant performance for conduit-fed electrical installations in both new construction and renovation projects.
Manufacturer Resources
Spec Sheet
Product Specs
- list_batch:
- RACO-20260916
- Product Type:
- Outlet Box
- Product Size:
- 4 in
- Product Depth:
- 1.5 in
- Product Shape:
- Square
- Drawn or Welded:
- Welded
- Bracket Type:
- No Bracket
- Wiring System:
- Conduit
- Knockouts:
- 1/2 in;1/2 - 3/4 in Combination (TKO)
- Certified Listed:
- UL Listed
- Department:
- Electrical
- Product Subgroup:
- Electrical Boxes
- Product Group:
- Boxes & Enclosures
RACO 189SM – Frequently Asked Questions
1) Will the RACO 189SM 4 in. square box work for a conduit run, or does it need a mounting bracket?
The 189SM ships with no bracket, so it is meant to be supported by the conduit itself or by hardware you provide. It is built for conduit wiring systems. If you need a box that nails or screws to a stud, pick a bracketed version instead.
2) What size conduit can I bring into the RACO 189SM square box, and how many entries do I get?
Ten 1/2 in. knockouts plus six 1/2 - 3/4 in. combination (TKO) knockouts. So you can land 1/2 in. conduit anywhere and step up to 3/4 in. at the six combination locations, with sixteen possible entry points total.
3) Does the RACO 189SM come with a ground pigtail, or do I have to add one?
A 10 inch #12 stranded copper grounding pigtail is factory installed, and the box has a raised ground stamping for a dedicated equipment ground connection. You do not need to add a ground screw and lead in the field.
4) Is the RACO 189SM UL Listed for an inspected commercial installation?
Yes, the 189SM square steel box is UL Listed.
5) Can I mount switches or receptacles in the 189SM, or is it only a junction box?
Both. At 1-1/2 in. deep it is used as a device and outlet box for switches and receptacles as well as a junction point in conduit and raceway systems. For a device, add a 4 in. square plaster ring or device cover in the depth that brings the device flush with your finished wall.
6) Welded or drawn steel box, and does it matter on a commercial job?
The 189SM is welded, meaning a one-piece rigid body rather than a formed drawn shell. Welded construction holds its shape through rough handling and conduit pulls, which is why it is the usual choice on commercial and industrial conduit work.
7) What is the exact RACO part number to order this 4 in. welded square box by?
Order it as RACO 189SM. That is the manufacturer part number for the 4 in. welded square steel box, 1-1/2 in. deep, no bracket.
How fast can I get the RACO 189SM 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 RACO 189SM come with a warranty?
Absolutely. The RACO 189SM 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 RACO 189SM?
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