Generator Installation
Install automatic transfer switch (ATS) backing generators using gas, LPG, or diesel.
Key Takeaways
- Load calculation performed before generator selection — right-size unit prevents both overload and fuel waste from oversizing
- Automatic transfer switch (ATS) prevents back-feed and provides 10-second automatic startup on grid failure
- Generators installed without proper sizing calculations run at overload during peak AC demand, causing premature engine wear
Table of Contents
Generator Sizing: The Calculation That Determines Everything
The single most important decision in generator installation is correct sizing. An undersized generator runs at overload during peak demand — particularly during AC startup surge current — causing engine overheating, shortened service life, and potential failure precisely when it is most needed. An oversized generator wastes fuel and runs inefficiently at low load percentages, which causes engine glazing over time. Correct sizing requires a formal load calculation that accounts for all connected loads and motor start surge requirements.
Transfer Switch Safety: Preventing Back-Feed to the CNFL Grid
An improperly wired transfer switch is one of the most dangerous electrical hazards in residential and commercial properties. When a generator is connected to a structure's electrical panel without a properly interlocked transfer switch, generator power can flow backward through the meter and onto the distribution line — creating a potentially lethal voltage on a line that CNFL workers may assume is de-energized. Costa Rica's CEI (Codigo Electrico Nacional) and CNFL interconnection requirements mandate specific transfer switch configurations. We install only CNFL-compliant ATS configurations.
Commissioning: Verifying Performance Before the First Real Outage
A generator that has been installed but never tested under full load may have any number of latent faults: a fuel system restriction that limits power under load, an ATS that fails to transfer after a specific delay period, an exhaust restriction that causes thermal shutdown, or a grounding fault that triggers the main breaker. Our commissioning process includes a full-capacity load test, an ATS transfer simulation test, and verification of automatic shutdown functions. Only after passing all commissioning tests is the system handed over to the owner.
Why Choose Us vs. Unlicensed Electricians
| Feature | Costa Rica Property Services | Common Alternatives |
|---|---|---|
| Compliance | 100% CFIA and NEC-compliant installations with permits | Informal wiring without permits or load calculations |
| Materials | Marine-grade breakers, anti-oxidant terminals, UV conduit | Standard hardware degrading within 1-2 rainy seasons |
| Inspection Sign-off | Completed CFIA inspection certificate provided | No official documentation after work |
Direct Answers (AEO)
What size generator do I need for a Costa Rica home or business?
Generator sizing requires a load calculation — not a rough estimate. We measure or calculate the total connected load in kVA, including motor start surge current for air conditioners and pumps (which can be 3-5x running current). A typical 3-bedroom home with 2 split AC units, water pump, refrigerator, and lighting requires 8-12 kVA. A commercial property with multiple AC units and equipment requires a site-specific calculation.
What is an automatic transfer switch and do I need one?
An automatic transfer switch (ATS) monitors grid voltage and automatically starts the generator and transfers load within 10-15 seconds of a grid failure — without any manual intervention. For vacation rentals, home offices, or any property where you may be absent during an outage, an ATS is essential. Manual transfer switches require someone present to physically switch the connection.
What are the CFIA requirements for generator installation in Costa Rica?
Generator installations in Costa Rica that modify the electrical panel or install a transfer switch must be designed and supervised by a CFIA-registered electrical engineer. The installation must comply with the Codigo Electrico Nacional (CEN), which requires proper bonding, grounding, over-current protection, and transfer switch wiring that prevents back-feed to the utility grid.
How often does a generator need maintenance in Costa Rica's climate?
We recommend quarterly maintenance for generators in Costa Rica: engine oil and filter change, air filter inspection, fuel system check (drain condensation from diesel tanks), battery electrolyte check, belt and coolant inspection, and a 30-minute load test. Coastal locations with salt air require more frequent inspection of electrical connections and fuel system components.