UL 891 Switchboard BOM Example
Complete bill of materials examples for UL 891 switchboards, including single main, main-tie-main, and high-capacity configurations. Component specifications and selection guide.
Overview
A Bill of Materials (BOM) is a comprehensive list of all components, parts, and assemblies required to build a UL 891 switchboard. Understanding the BOM helps engineers and procurement teams verify component selection, estimate costs, and ensure proper specification for the project.
What's Included in a Switchboard BOM?
- • Main bus and bus connections
- • Main circuit breakers and feeder circuit breakers
- • Current transformers and potential transformers
- • Power meters and protective relays
- • Surge protective devices
- • Enclosure, doors, and covers
- • Wiring, terminals, and hardware
- • Nameplates, labels, and documentation
BOM Configuration Examples
Single Main, 2000A
Basic configuration with one main breaker and multiple feeders
| Item | Description | Qty | Unit |
|---|---|---|---|
| Main Bus | 2000A, copper, 3-phase, fully rated | 1 | set |
| Main Breaker | ACB, UL 1066, 2000A frame, 3-pole, adjustable trip | 1 | ea |
| Feeder Breaker 1 | MCCB, UL 489, 800A frame, 3-pole, thermal-magnetic | 4 | ea |
| Feeder Breaker 2 | MCCB, UL 489, 400A frame, 3-pole, thermal-magnetic | 8 | ea |
| Feeder Breaker 3 | MCCB, UL 489, 225A frame, 3-pole, thermal-magnetic | 12 | ea |
| Current Transformer | 2000:5A, 0.3 class, for main metering | 3 | ea |
| Power Meter | Digital, multifunction, Modbus communication | 1 | ea |
| Surge Protective Device | Type 2, 480V, 100kA SCCR | 1 | ea |
| Enclosure | NEMA 1, indoor, ANSI 61 gray paint | 1 | set |
Component Details
Circuit Breakers
Air Circuit Breaker (ACB)
Used for main breakers and large feeders. Adjustable long-time, short-time, instantaneous, and ground fault trip. Drawout or fixed-mounted.
Insulated-Case Circuit Breaker (ICCB)
Used for medium-sized feeders. Electronic trip units with adjustable settings. Higher interrupting capacity than MCCB.
Molded-Case Circuit Breaker (MCCB)
Used for smaller feeders and branch circuits. Thermal-magnetic or electronic trip units. Most cost-effective option.
Metering & Protection
Current Transformer (CT)
Provides current measurement for metering and protective relaying. Class 0.3 for metering, Class C for relaying.
Power Meter
Measures voltage, current, kW, kVA, kVAR, power factor, frequency, and energy. Communication via Modbus RTU/TCP or BACnet.
Surge Protective Device (SPD)
Protects against transient voltage surges. Type 1 for service entrance, Type 2 for downstream protection.
Enclosures
NEMA 1 Enclosure
For indoor electrical room installations. Prevents contact with live parts. Standard ANSI 61 gray paint.
NEMA 3R Enclosure
For outdoor installations. Rainproof construction with drip shields and conduit hubs. Prevents ice and rain entry.
NEMA 12 Enclosure
For indoor industrial environments with dust, lint, and fibers. Prevents dust entry and provides drip protection.
Custom BOM for Your Project
The BOM examples shown are typical configurations. Your actual BOM will be customized based on your single-line diagram, load requirements, and project specifications. Send us your SLD and requirements, and our engineering team will provide a detailed BOM with manufacturer part numbers and pricing.
Frequently Asked Questions
Need a Custom BOM for Your Project?
Send us your single-line diagram and project requirements. Our engineering team will provide a detailed BOM with manufacturer part numbers and pricing within 24 hours.
Request a Custom BOM