Introduction to Compact Substations
Compact substations (also called pad-mounted or prefabricated substations) combine MV switchgear, transformer, and LV distribution in one enclosure. They save space, reduce installation time, and deliver plug-and-play power. But with dozens of configurations available, choosing the right compact substation is challenging. Here are the top 10 compact substation selection tips.
What is a Compact Substation?
A compact substation integrates three sections into one enclosure:
- MV compartment – RMU or load break switch + fuse
- Transformer compartment – oil-immersed or dry-type transformer
- LV compartment – main breaker + feeders + metering
Top 10 Selection Tips
1. Choose the Right Transformer Capacity
Size the transformer for current load plus 20-30% future growth. Common ratings: 315 kVA, 500 kVA, 800 kVA, 1000 kVA, 1250 kVA, 1600 kVA, 2000 kVA.
| Application | Typical Capacity | Transformer Type |
|---|---|---|
| Residential Area | 315-630 kVA | Oil-immersed |
| Commercial Building | 800-1600 kVA | Dry type |
| Solar Farm | 1000-2500 kVA | Oil-immersed |
2. Pick Oil vs Dry Type Transformer
Oil-immersed transformers are cheaper, more efficient, and better for outdoor use. Dry-type transformers are fire-safe and required indoors or in densely populated areas.
3. Verify MV Switchgear Configuration
Choose between load break switch + fuse (economical) or VCB (higher reliability). For critical loads, specify circuit breaker type protection.
4. Count LV Feeders
Plan the LV distribution board carefully. How many outgoing feeders? Are they 3-phase or 1-phase? Do you need metering or surge protection on each?
5. Check Enclosure Protection Rating
Outdoor pad-mounted: IP44 minimum. Flood-prone areas: IP54 with raised plinth. Coastal installations: corrosion-resistant aluminum or stainless steel.
6. Evaluate Noise Requirements
Substations near bedrooms or hospitals need low-noise designs. Standard transformers emit 55-65 dB; silent versions get below 50 dB with acoustic enclosures.
7. Confirm Grid Code Compliance
Different countries require different protection relays, metering standards, and anti-islanding protection. Specify the destination country when ordering.
8. Think About Transportation
Large substations (over 2000 kVA) may need special transport permits. Confirm road access to site before finalizing dimensions.
9. Check Delivery Time
Standard compact substations ship in 4-6 weeks. Custom configurations may take 8-12 weeks. Plan procurement accordingly.
10. Evaluate After-Sales Support
Choose a manufacturer who provides commissioning support, spare parts, and a 2-year minimum warranty. Electric-GS offers 24/7 technical support worldwide.
Frequently Asked Questions
How much does a compact substation cost?
A 1000 kVA compact substation typically costs $15,000-$30,000 depending on configuration, transformer type, and switchgear brand.
What is the installation time?
A prefabricated compact substation arrives on site fully assembled. Installation typically takes 1-3 days including cable connection and commissioning.
Can compact substations be installed indoors?
Yes, but you must use dry-type transformers and ensure adequate ventilation. Indoor substations also require fire-rated walls.
What is the typical lifespan?
With regular maintenance, compact substations last 25-30 years. The transformer may need oil testing and filtering every 5-10 years.
About Electric-GS
Electric-GS designs and manufactures compact substations, RMU, and switchgear for global infrastructure projects. Our prefabricated substations are type-tested and shipped to 40+ countries.
Request a custom quote: info@electric-gs.com | WhatsApp: +86 135 8897 8050 | See our product range on the sister site.