Switchgear is the traffic-control centre of any electrical system. Choose the wrong class and you risk blowing budgets, unwanted downtime and worst of all, safety incidents. Below is a buyer-focused snapshot that helps procurement and facilities teams decide when low-voltage (LV) gear is enough and when medium-voltage (MV) gear is mandatory.
First, What Is Switchgear?
Switchgear is a metal-enclosed assembly of disconnect switches, circuit breakers and fuses that controls, protects and isolates electrical circuits. Interrupting fault currents and isolating live sections shields personnel from arc-flash, limits equipment damage and lets crews re-energize unaffected loads quickly in low- or medium-voltage systems.
Know Your Voltage & Current Window
| Class | Typical Ratings | Core Applications | VCM Rental Range* |
| Low-Voltage (LV) | ≤ 600 V, up to 800 A | MCCs, data rooms, panelboards, temporary site power | Breakers 30–800 A in NEMA 3R |
| Medium-Voltage (MV) | 1–38 kV, up to 1,200 A | Utility feeders, genset tie-ins, substations | Switchgear 50–1 200 A, fuse-interchangeable, NEMA 3R |
*Pulled from VCM Solutions rental fleet specifications.
When Low-Voltage Gear Is the Smarter Buy
Choose LV switchgear when:
- Loads sit below 600 V. Most commercial panels, lighting, and small motors.
- Footprint is tight. LV enclosures are lighter and ship fully assembled, cutting install time.
- Project life is short. Temporary builds and shutdowns rarely justify MV capital.
- Arc-flash incident energy is manageable (<8 cal/cm²). PPE requirements stay modest.
LV breakers with draw-out racking let crews isolate a faulty feeder in minutes without killing the whole board.
When Medium-Voltage Is Necessary
Move up to MV switchgear when:
- Feed exceeds 600 V—utility mains, campus loops, mining camps, LNG plants.
- Long cable runs would incur prohibitive losses at LV.
- Generator paralleling requires synchronizing multiple 13.8 kV sets.
- Future expansion is likely; MV switchgear scales better and handles higher fault currents.
MV cabinets are metal-clad and arc-resistant by default. Look for C37.20-compliant arc-fault channels that vent energy safely upward—critical in occupied substations.
Safety Checklist
Every RFQ should demand these four features:
- Arc-flash containment tested to IEEE C37.20.7 for personnel protection.
- Mechanical interlocks that block racking a breaker under load.
- Remote racking or motor operators for high-incident-energy cells (>40 cal/cm²).
- Smart relays (SEL, ABB, Schneider) that log events and push diagnostics to SCADA.
Remember: Safety features affect lead time. Confirm stock status early if your outage window is firm.
Rent or Buy? Here are Three Fast Filters
Before you lock in a purchase order, pause and ask: Do we need permanent switchgear on the books, or will a short-term rental keep us lean and flexible? Most procurement teams reduce the decision to three quick factors: timeline, financial treatment, and the level of technical support required.
For example,
- Timeline: Outages under 18 months almost always favour rental.
- CapEx vs OpEx: Rental keeps balance sheets light and bypasses depreciation schedules.
- Support: VCM’s rental units arrive pre-tested and include 24/7 breaker swap-out—ideal when internal tech crews are stretched.
Final Sizing Steps
- Gather fault-current data from the utility—your AIC rating hinges on it.
- List feeder counts now and at end-of-life to avoid costly bus extensions.
- Specify enclosure rating (NEMA 3R/4X/7) to match the environment—corrosion hits TCO hard.
Need Equipment Now?
Need help deciding between low-voltage and medium-voltage switchgear? Connect with the experts at VCM Solutions today for a tailored rental or purchase solution. Contact us today for a fast quote and availability.