When PLN drops in Bali — and across much of the island it drops often — the difference between an automatic transfer switch (ATS) and a manual changeover is the difference between your power blinking back in 10 seconds and someone walking out to the genset in the rain at 2am. Both are valid choices. The right one depends on how the property is used, who is on site, and what a blackout actually costs you. This guide lays out the trade-offs honestly.
What Each One Actually Does
A manual changeover switch is a heavy-duty selector that physically connects your building to either PLN or the generator — never both. When the power fails, someone starts the genset, lets it warm up, and throws the switch. To go back, they reverse it and shut the genset down. It is simple, robust and cheap, and there is almost nothing to go wrong electronically.
An automatic transfer switch (ATS) is a controller plus contactors that senses the PLN outage, signals the genset to auto-start, waits for it to stabilise, then transfers the load — typically within 8–15 seconds, with no human involved. When PLN returns it transfers back and shuts the genset down after a cool-down. It is the standard for villas rented to guests, businesses and anyone who is not always on site. We cover the install in detail on our ATS installation page.
Side by Side
| Factor | Manual Changeover | Automatic (ATS) |
|---|---|---|
| Switchover time | 2–10 min (someone must act) | 8–15 seconds, hands-off |
| Needs a person on site | Yes | No |
| Works when you are away | No | Yes |
| Typical added cost (IDR) | Lower — included in basic installs | Add on top of the genset |
| Failure points | Very few | Controller, battery, contactors |
| Best for | Owner-occupied homes, workshops with staff | Rental villas, guesthouses, businesses, remote owners |
For exact figures on both options for your property, see our pricing guide or send us your setup on WhatsApp — ATS pricing depends on the genset size and whether the controller is already built into the unit.
When We Recommend an ATS
- Rental villas and guesthouses. Guests will not (and should not) operate a generator. A blackout that lingers because nobody knows how to switch over turns into a bad review. ATS makes the outage almost invisible.
- Properties you do not live at. If you manage from abroad or another part of the island, ATS plus a remote-monitoring option means power restores itself and you get notified.
- Businesses with cold chain or equipment. Restaurants, clinics and anyone with fridges, freezers or sensitive electronics cannot afford a 5-minute gap, let alone the hours one takes if the changeover is manual and nobody is there.
- Frequent, short outages. In areas where PLN flickers several times a week, manually switching back and forth becomes a chore; ATS handles it silently.
When a Manual Changeover Is the Smarter Choice
ATS is not always worth it. If you live at the property, are usually home, and outages are rare, a manual changeover saves money and removes electronic components that can fail. Workshops and small businesses with staff present during operating hours often do fine with manual — the person who would notice the blackout is already there. We have talked plenty of owners out of an ATS when the numbers did not justify it; the goal is the right setup, not the most expensive one.
Retrofitting an ATS to an Existing Generator
You do not need to replace your genset to add automatic transfer — in most cases we can retrofit an ATS to a unit that currently uses a manual switch, provided the engine has (or can be fitted with) an electric start and an auto-start controller. We assess the controller, battery, charging and panel space, then quote the upgrade. It is one of the most common installation jobs we do for owners who started manual and later began renting the place out.
Frequently Asked Questions
How fast does an ATS restore power after a blackout?
Can I add an ATS to my existing generator later?
Is a manual changeover safe?
Does an ATS need maintenance?
Not Sure Which You Need?
Tell us how the property is used and how often the power drops — we will recommend ATS or manual honestly, with the IDR figures for each. Free advice on WhatsApp, same day.
WhatsApp an Engineer