Tuesday, 2 June 2026
Mini Power Centers Explained: When Integrated Distribution Makes Sense
Most low-voltage distribution gets built up from discrete components. A transformer here, a ...
Specialty Products
Mini Power Centers
Rex Power Magnetics Mini Power Centers provide a compact, self-contained solution for distributing low-voltage power in industrial, commercial, and construction environments. Each unit combines a transformer, primary and secondary protection, and distribution panel in a single enclosure — simplifying installation, saving space, and reducing overall system cost.
Designed for durability and safety, Rex Mini Power Centers are ideal for applications where reliable power is required close to the point of use. Typical installations include plant floor machinery, lighting systems, portable power distribution, and maintenance or construction sites. The integrated design minimizes wiring complexity and ensures compliance with CSA and UL requirements for overcurrent protection and grounding.
Rex offers a range of standard configurations and ratings, with options for indoor or outdoor use. Enclosures are available in NEMA-rated designs to suit environmental conditions, and units can be custom-engineered for specific voltage combinations or load requirements.
Rugged, efficient, and easy to install, Rex Power Magnetics Mini Power Centers provide a dependable and convenient power distribution solution — backed by proven engineering quality and manufacturing excellence.
| Capacity |
|
| Voltage Class | 600V Max |
| Secondary Voltage |
|
| Cooling | Self Cooled (ANC) |
| Frequency | 60Hz (50/60Hz Optional) |
| Conductors | Copper (Cu) or Aluminum (Al) Windings |
| Temperature Rise | 130°C (115°C & 80°C Optional) |
| Insulation System | 200°C |
| Impregnation | N/A (Core & Coil Are Encapsulated In a Block of Polyurethane and Silica Sand) |
| Primary Taps | Typically +/-2 x 2.5% Taps (Refer to Catalog) |
| Sound Level | Meets NEMA ST-20 |
| Enclosure Type | Type 3R Indoor/Outdoor |
| Enclosure Finish | ANSI 61 Grey |
| Mounting | Wall Mountable |
| Primary Breaker | 14kAIC rated molded case circuit breaker (EATON) |
| Loadcenter | Aluminum Bus Load Center, Suitable For EATON Type BR Push-On Branch Breakers (Optional Copper Bus Load Center, Suitable For EATON Type BAB Bolt-On Branch Breakers) |
| Warranty | 12 Months (See Warranty and Limitations) |
| Quality System | ISO 9001:2015 Quality Management System |
| Certifications |
|
| Optional Features & Accessories |
|
Product Catalogs
Mini Power Center Catalog (English)
Mini Power Center Catalog (French)
Instruction Sheets & Manuals
Installation, Operation and Maintenance Manual (English)
Other Resources
Configure a Mini Power Center to build its Rex catalog part number. Codes follow the Rex catalog numbering system.
Options
Special Features / Accessories
Rex Part Number
—
This tool assembles a catalog part number from the options you select, following the Rex Power Magnetics catalog numbering system. Not every combination of options is necessarily a standard or available product, and some configurations may require review or a custom quote. For a voltage not listed, the code ‘X’ is used (600 V max) and the value specified separately. Rex Power Magnetics makes no representations as to the accuracy of the information generated by this tool; part numbers should be confirmed with Rex before ordering. Contact Rex Power Magnetics to verify availability, pricing, and specifications.
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- Single Phase: 5, 7.5, 10, 15, 25 & 30kVA
- Three Phase: 9, 15, 22.5, 30 & 45kVA
- Single Phase: 240/120V
- Three Phase: 208Y/120V
- CSA Certified
- UL Listed (Push on branch breaker loadcenters only)
- 50/60 Hz Frequency
- Electrostatic Shield Installed Between Primary and Secondary
- Copper Bus Load Center
- Bolt-On Breaker Load Center
- Branch Breakers Supplied (Per Request)
- Type 4 or 4X (304 Stainless Steel) Enclosure
- Eaton FD, HFD, and FDC Primary Main breaker With 18kA, 25kA, and 35 kA Interrupting Capacity.
- Secondary Main Breaker with Higher Than Standard Interrupting Rating
- Custom Specified Paint Color
Rex Power Magnetics Mini Power Centers provide a compact, self-contained solution for distributing low-voltage power in industrial, commercial, and construction environments. Each unit combines a transformer, primary and secondary protection, and distribution panel in a single enclosure — simplifying installation, saving space, and reducing overall system cost.
Designed for durability and safety, Rex Mini Power Centers are ideal for applications where reliable power is required close to the point of use. Typical installations include plant floor machinery, lighting systems, portable power distribution, and maintenance or construction sites. The integrated design minimizes wiring complexity and ensures compliance with CSA and UL requirements for overcurrent protection and grounding.
Rex offers a range of standard configurations and ratings, with options for indoor or outdoor use. Enclosures are available in NEMA-rated designs to suit environmental conditions, and units can be custom-engineered for specific voltage combinations or load requirements.
Rugged, efficient, and easy to install, Rex Power Magnetics Mini Power Centers provide a dependable and convenient power distribution solution — backed by proven engineering quality and manufacturing excellence.
| Capacity |
|
| Voltage Class | 600V Max |
| Secondary Voltage |
|
| Cooling | Self Cooled (ANC) |
| Frequency | 60Hz (50/60Hz Optional) |
| Conductors | Copper (Cu) or Aluminum (Al) Windings |
| Temperature Rise | 130°C (115°C & 80°C Optional) |
| Insulation System | 200°C |
| Impregnation | N/A (Core & Coil Are Encapsulated In a Block of Polyurethane and Silica Sand) |
| Primary Taps | Typically +/-2 x 2.5% Taps (Refer to Catalog) |
| Sound Level | Meets NEMA ST-20 |
| Enclosure Type | Type 3R Indoor/Outdoor |
| Enclosure Finish | ANSI 61 Grey |
| Mounting | Wall Mountable |
| Primary Breaker | 14kAIC rated molded case circuit breaker (EATON) |
| Loadcenter | Aluminum Bus Load Center, Suitable For EATON Type BR Push-On Branch Breakers (Optional Copper Bus Load Center, Suitable For EATON Type BAB Bolt-On Branch Breakers) |
| Warranty | 12 Months (See Warranty and Limitations) |
| Quality System | ISO 9001:2015 Quality Management System |
| Certifications |
|
| Optional Features & Accessories |
|
Product Catalogs
Mini Power Center Catalog (English)
Mini Power Center Catalog (French)
Instruction Sheets & Manuals
Installation, Operation and Maintenance Manual (English)
Other Resources
Configure a Mini Power Center to build its Rex catalog part number. Codes follow the Rex catalog numbering system.
Options
Special Features / Accessories
Rex Part Number
—
This tool assembles a catalog part number from the options you select, following the Rex Power Magnetics catalog numbering system. Not every combination of options is necessarily a standard or available product, and some configurations may require review or a custom quote. For a voltage not listed, the code ‘X’ is used (600 V max) and the value specified separately. Rex Power Magnetics makes no representations as to the accuracy of the information generated by this tool; part numbers should be confirmed with Rex before ordering. Contact Rex Power Magnetics to verify availability, pricing, and specifications.
Photos
Videos
Photos
Videos
Faqs
- General FAQs
- Technical Specification FAQs
- Installation & Application FAQs
- Performance & Product Selection FAQs
- Protection, Standards, Commissioning & Ordering FAQs
A mini power center is a compact, self-contained power distribution unit that combines a transformer, primary and secondary overcurrent protection, and a panelboard within a single enclosure. It steps down a facility’s main voltage (typically 480 V or 600 V) to a lower utilization voltage such as 208/120 V for lighting and receptacle loads. Rex Power Magnetics mini power centers are designed for simplicity, safety, and reliability, making them ideal for localized or temporary power distribution in industrial, commercial, and construction environments.
Mini power centers eliminate the need for separate transformer and panelboard installations, reducing space requirements and installation time. They arrive as pre-wired, factory-assembled units that can be quickly mounted and connected. This integrated design simplifies coordination between components, ensures proper short-circuit ratings, and improves electrical safety. Rex Power Magnetics mini power centers offer a clean, compact solution for distributing low-voltage power close to the point of use — perfect for retrofits, plant expansions, or modular construction projects.
Rex Mini Power Centers are used in commercial and industrial environments that require localized low-voltage power distribution. They are particularly useful where an existing electrical supply must be converted to a lower voltage and distributed to several electrical circuits.
Common applications include manufacturing facilities, commercial buildings, warehouses, construction sites, laboratories, maintenance areas, and temporary power installations.
In industrial facilities, Mini Power Centers can supply power to machinery controls, maintenance equipment, lighting, and receptacles. In commercial buildings, they provide localized distribution for offices, parking structures, and other areas requiring lower-voltage electrical circuits.
Rex Mini Power Centers are available in single-phase and three-phase configurations, with indoor and outdoor enclosure options to accommodate different installation environments.
Yes. A Rex Mini Power Center is designed to distribute electrical power to multiple branch circuits through its integrated distribution panel. This allows one unit to supply several electrical loads rather than requiring a separate transformer for each piece of equipment.
For example, a Mini Power Center can provide power for lighting, receptacles, control systems, and other compatible electrical equipment within a commercial or industrial facility.
The number of circuits it can support depends on the distribution panel configuration, available circuit breaker spaces, transformer kVA rating, and total connected load. Rex offers configurable load centers with optional branch circuit breakers to accommodate different distribution requirements.
When selecting a Mini Power Center, consider both existing electrical loads and potential future expansion to ensure that the transformer and distribution panel have sufficient capacity.
The standard mini power center loadcenter has an aluminum bus that accepts Eaton Type BR push-on (plug-in) branch breakers. The optional loadcenter has a copper bus for Eaton Type BAB bolt-on breakers. Both fit the same enclosure and connect to the same secondary main.
Push-on breakers clip onto the bus stab. They are quick to add or replace, which suits temporary and construction power where the panel schedule changes weekly. Bolt-on breakers are fastened to the bus with a screw, which gives a more secure connection under vibration, thermal cycling and repeated load switching; they are the usual specification for permanent industrial panels, for units on skids or mobile equipment, and where a plant standard calls for bolt-on devices.
Rex mini power centers use encapsulated transformers to protect windings and electrical components from dust, moisture, and vibration.
The sealed construction eliminates the need for ventilation openings, allowing compact, wall-mounted Type 3R, 4, or 4X enclosures suitable for outdoor and demanding industrial environments. It also improves mechanical durability, although the encapsulated windings cannot be rewound or re-varnished.
Each mini power center integrates an encapsulated dry-type transformer with primary and secondary circuit breakers, a distribution panelboard, and a NEMA-rated enclosure. The entire assembly is mounted within a ventilated steel or stainless steel enclosure designed for optimal cooling and accessibility. All internal wiring and protective devices are factory-tested to ensure reliable, code-compliant operation upon installation.
The interrupting capacity of the primary breaker must equal or exceed the available short-circuit current at the line terminals of the mini power center. That value comes from the project short-circuit study.
As an illustration, a 1,000 kVA, 5.75 percent impedance plant transformer at 600 V has a full-load current of 962 A and an infinite-bus fault current of 962 / 0.0575, about 16.7 kA. A mini power center fed directly from that switchboard, or through a short feeder, sees more than 14 kA and needs the 18 kA rated primary main breaker. The same unit at the end of a long feeder sees substantially less, and the standard 14 kAIC breaker may suffice; the study should confirm it. On a 480 V system the same plant transformer delivers about 20.9 kA at the bus, which pushes the selection to the 25 kA near the source.
Interrupting capacity is not a series rating: the primary breaker must stand on its own rating unless Rex has specifically evaluated a series combination. For a portable unit that may be connected at different points on a site, order the 35 kA option so the unit is acceptable anywhere it is plugged in. The Knowledge Hub article Transformer Impedance: Impact on Fault Current covers the calculation.
Rex mini power centers offer copper or aluminum windings with identical kVA ratings, voltages, insulation systems, and certifications.
Aluminum windings are lighter and more economical, while copper offers higher conductivity and may suit specific project requirements. Overall enclosure dimensions and field wiring typically remain unchanged, as connections are made through the breakers and loadcenter rather than directly to the windings.
Mini power centers are used wherever local low-voltage power distribution is required from a higher-voltage source. Common applications include industrial manufacturing lines, construction sites, temporary power setups, maintenance areas, and equipment rooms. They are also widely used in data centers, laboratories, and commercial buildings where isolated distribution zones are beneficial. Rex Power Magnetics designs each mini power center for durability and safety in both permanent and portable applications.
Yes. Outdoor-rated models are supplied with weatherproof NEMA 3R, 4 or 4X enclosures and are built to withstand temperature fluctuations, rain, dust, and humidity. For particularly harsh or corrosive locations, optional stainless steel can be specified. Proper installation, including grounding and ventilation clearances, ensures reliable operation in all environmental conditions.
A Rex mini power center uses encapsulated construction, allowing wall mounting without additional side or rear ventilation clearance. However, its integrated breakers require code-compliant working space in front of the enclosure, typically 1 m under the CEC or 3 ft under the NEC, along with adequate width, headroom, and breaker accessibility.
For outdoor installations, maintain proper mounting orientation, weather protection, and snow clearance. See the Rex Enclosure Drawings for installation dimensions.
Yes. A Rex mini power center can operate outdoors in cold conditions, provided its breakers and enclosure are suitable for the ambient temperature. At −30°C, breaker performance may be affected, while condensation and frost can damage internal components. Ensure adequate snow clearance, sealed conduit entries, and suitable cold-rated equipment. Contact Rex engineering to confirm low-temperature suitability and available enclosure or heating options.
Yes. A Rex mini power center can operate from a compatible 480 V or 600 V portable generator, provided generator capacity, transformer inrush, voltage stability, and fault protection are properly coordinated.
Two standard mini power centers should feed separate loadcenters rather than having their secondaries paralleled. For additional capacity, use separate units with independent circuits or consult Rex about a custom distribution arrangement.
Typical mining uses of the mini power center are 120 V and 208 V distribution on crusher and screening skids, conveyor drive houses, dewatering pump stations and camp infrastructure fed from a 600 V mine distribution. The encapsulated transformer is immune to dust and vibration, the enclosure is a single wall-mountable Type 3R box, and every protective device is already selected and certified, which shortens site time.
The options that matter on a skid are:
• Bolt-on breaker (copper bus) loadcenter, so branch breakers cannot vibrate loose from a push-on stab during transport.
• Type 4 or Type 4X (304 stainless) enclosure, for dust and washdown; 4X where the atmosphere is corrosive or the skid moves between sites.
• Eaton FD, HFD or FDC primary breaker at 18, 25 or 35 kA, because fault current at a mine substation is often above 14 kA.
• Branch breakers are factory supplied, so the loadcenter is complete and matched.
Both electrical load and circuit count determine the correct Rex mini power center rating. For example, a maintenance shop with twelve receptacle circuits, four lighting circuits, and a 3 hp compressor may require approximately 28 kVA after applicable demand factors, making a 30 kVA unit suitable. However, the loadcenter must also accommodate all required breaker poles and spare circuits. If the available spaces are insufficient, a larger unit or revised circuit layout may be necessary.
A Rex mini power center meets NEMA ST-20 sound level requirements. Its encapsulated construction reduces transformer hum, making it suitable for offices, laboratories, and camp buildings.
For quieter operation, mount the unit securely on a rigid surface, maintain proper input voltage, and avoid shared walls with noise-sensitive rooms. For projects with specific acoustic requirements, request sound test data from Rex.
Yes. Rex Power Magnetics offers fully customized mini power centers to meet specific electrical and mechanical requirements. Options include custom voltage ratios, kVA ratings, circuit configurations, panelboard layouts, and enclosure materials. Additional accessories such as branch breakers and surge suppression can be integrated upon request. Each customized unit is engineered, assembled, and tested to the same rigorous standards as standard models, ensuring consistent reliability and safety across all installations.
The Mini Power Center IOMM sets the procedure; these checks catch most problems.
• Inspect for shipping damage to the enclosure, breaker handles and the encapsulated block.
• Confirm the nameplate against the drawings: kVA, primary voltage, tap position and secondary voltage.
• Measure the supply voltage at the feeder and set the primary tap to match (for example the 585 V tap on a 585 V bus).
• Torque the field connections on the primary breaker lugs, ground bar and neutral bar to the IOMM values; factory connections need inspection, not re-torquing.
• Verify the bonding: grounding electrode conductor and equipment bonding conductor landed, neutral-to-ground bond present once at the factory location, no downstream neutral-ground connection.
• Insulation resistance test the transformer primary to ground and primary to secondary with the breakers open, and record the value as a baseline.
• Exercise every breaker open and closed, and confirm all branch breakers are the specified Eaton type.
• Energize with the secondary main open, check secondary voltage on all legs and line-to-line, then close the secondary main and the branch breakers in turn while checking phase rotation and voltage.
Record the no-load secondary voltage, the tap position and the insulation reading in the commissioning file; they are the reference for later troubleshooting. The Knowledge Hub article Transformer Commissioning: Critical Checks for Safe Energization expands on each step.
The encapsulated transformer in a Rex mini power center needs almost nothing: there is no varnish to inspect, no ventilation path to clean and no winding to re-torque. The maintenance that matters is on the breakers, bus and enclosure, so follow panelboard practice.
At an annual visit, or every six months for a portable unit or one in a dusty or corrosive site:
• De-energize, open and inspect the loadcenter for discolouration at breaker stabs and bus connections, which indicates a loose or overheated joint.
• Check torque on the field connections at the primary breaker, ground bar and neutral bar.
• Exercise the primary main, secondary main and branch breakers to keep the mechanisms free.
• Thermal-scan the bus and breaker terminals under load; log the hottest point and the load at the time.
• Clamp-meter each secondary phase and the neutral; rising neutral current signals growing harmonic load.
• Inspect the enclosure: gasket, drip shield, conduit seals and evidence of water entry.
• Repeat the insulation resistance test every few years and compare with the commissioning baseline.
Because the transformer cannot be repaired, a falling insulation reading or a rising surface temperature at constant load is a signal to plan replacement rather than a repair. The Knowledge Hub article Transformer Maintenance: Essential Checklist provides a fuller checklist, and the Documentation page holds the IOMM.
Rex publishes a Product Guide Specification for the mini power center, written in the three-part format used by consulting engineers so it can be placed in Division 26 of a project specification with minimal editing. It defines the product as an integrated assembly of an encapsulated dry-type transformer, primary and secondary molded-case breakers and a loadcenter in a single enclosure, and lists the ratings, materials and options a compliant product must provide.
To use it well, edit the bracketed choices rather than rewriting the text: kVA and phases from the catalogue range; primary voltage (480 or 600 V) and secondary (240/120 V or 208Y/120 V); temperature rise (130°C standard, 115°C or 80°C); winding conductor; enclosure type (3R, 4 or 4X stainless); loadcenter type (aluminum bus push-on or copper bus bolt-on); primary breaker interrupting rating (14 kAIC or 18, 25, 35 kA); electrostatic shield; 50/60 Hz; branch breakers supplied; and paint colour. State the certification required, remembering that a UL-listed assembly limits the choice to the push-on loadcenter.