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BostonBackup Power
Residential electrical panel where a RoseWater HUB connects

Power quality explained How a RoseWater HUB Works

Why your house sees power problems every day, what they do to your equipment, and how a HUB stops them before they reach the panel.

The short answer

What does a RoseWater HUB do?

A RoseWater HUB takes power from the grid, solar or a generator, strips out surges, sags, spikes and noise, and rebuilds a clean 120 V, 60 Hz sine wave for your panel, with a battery on the same path that carries the house the moment the grid fails. Because the HUB is always supplying the house, there is no switchover and no gap.

Most backup equipment waits for an outage. A HUB works every second of the day, which is why RoseWater calls it a power foundation rather than a backup box.

Utility grid

Your normal supply from Eversource, National Grid or your local utility.

Solar (optional)

Up to 10 kW through RoseWater's SBX10 solar box.

Generator (optional)

One or more generators can feed the HUB during a long outage.

RoseWater HUB

Every source comes in through industrial surge and lightning protection. Double-conversion inverters rebuild a clean 120 V, 60 Hz sine wave. The battery sits on the same path, ready to fill any sag or outage instantly.

  • Protect
  • Rebuild
  • Store

Your electrical panel

The circuits the HUB serves, tied in by a licensed electrician.

Your home

Lighting, network, AV, controls, kitchen, HVAC controls and whatever else your plan covers.

The HUB stays between every power source and the circuits it serves, all day, every day. There is no transfer switch to throw when the grid fails.

Power quality

What power problems does a home see?

The five power problems homeowners run into most are surges, spikes, sags, electrical noise and outages, and the first four happen far more often than the last. RoseWater groups power disturbances into ten IEEE categories, and these five cover what most homes feel. U.S. customers averaged a little over seven hours without power in 2021, according to EIA figures that RoseWater cites, yet the small disturbances arrive every day.

The damage is usually gradual. Power supplies, LED drivers and control processors wear out early from thousands of small events rather than one big one.

Surge

Voltage rises above normal for a moment, often when large loads switch off or the utility switches lines.

Stresses power supplies and shortens the life of electronics and LED drivers.

Spike

A very fast, very high voltage burst, from lightning nearby or switching on the grid.

Can destroy equipment in one hit. Smaller spikes do damage a little at a time.

Sag or brownout

Voltage drops below normal, for a fraction of a second or for minutes.

Lights dim, displays flicker and equipment reboots. You cannot divert power that is missing, so only stored energy fixes a sag.

Electrical noise

Interference riding on the sine wave from motors, dimmers, chargers and other loads in the house.

Shows up as hum, buzz and odd behavior in audio, video and control systems.

Outage

The grid stops supplying power, for one second or for days.

Everything without backup shuts off. Many outages are short enough that a generator never starts.

What the HUB sends to your panel

A rebuilt 120 V, 60 Hz sine wave with under 3% distortion, whether the source is the grid, the battery, solar or a generator.

Sags versus surges

Why is a sag harder to fix than a surge?

A sag is harder to fix because it is missing energy, and you cannot divert power that is not there. A surge is extra energy that a protector can send to ground. Fixing a sag takes stored energy ready to fill the gap instantly, which is exactly what the HUB’s battery does.

This is the reason a whole house surge protector covers only part of the problem. It handles the spikes and leaves the sags, the brownouts and the noise alone.

Transfer time

What happens in the first seconds of an outage?

With a RoseWater HUB nothing happens at all, because the house is already running on the HUB. With a standby generator the house goes dark while the engine starts and the transfer switch moves, which installers typically put at about 10 to 30 seconds. A battery behind a transfer switch closes that gap to a brief switchover, but it is still a switchover.

Ten seconds is long enough for network switches, control processors and AV components to shut off and then reboot one by one once power returns.

The grid fails at 0 seconds. A dark bar means the house has no power.

RoseWater HUB

There is zero transfer time, because the house is already running on the HUB, so nothing changes when the grid drops.

Battery behind a transfer switch

Switches over automatically when it senses the outage. Usually quick, but it is a switchover, and the time varies by model.

Standby generator

The engine has to start and reach speed before the transfer switch moves. Dealers typically quote about 10 to 30 seconds.

Illustration, not to scale for any single product. Generator timing from installer guidance; battery switchover time depends on the make and model.

Inside the HUB

How does the HUB stay online all the time?

The HUB stays online because every inverter module is a double-conversion module with both an AC and a DC input, so the battery is already connected and steps in the instant voltage drops. There is no transfer switch, and RoseWater does not use an eco mode that bypasses conditioning to save energy.

  • Rectifiers are used only to charge the batteries
  • Output stays under 3% total harmonic distortion
  • Surge and lightning protection covers the grid, solar and generator inputs
  • Critical parts are hot-swappable and serviced from the front without bypassing the system
  • Built-in monitoring records outages and voltage events for you and for us
  • Advanced lead-acid (carbon) batteries, more than 90% recyclable

Storage versus conditioning

Is a HUB a UPS or a home battery?

A HUB is both: it conditions power continuously like a UPS and stores energy for long outages like a home battery. A typical home battery waits behind a transfer switch and does nothing for power quality while the grid is up. A typical rack UPS conditions power but holds minutes of runtime, not hours.

Panel-level protection also reaches further than a rack UPS. It covers lighting, appliances, HVAC controls and plumbing systems, not just the equipment in the AV closet.

See how a HUB would cover your home. The Power Plan takes a few minutes and gives us what we need to size it.

Build Your Power PlanBook a consultation

FAQ

Power quality questions

What does zero transfer time mean?

What does zero transfer time mean?

Zero transfer time means the house never switches from one power source to another when the grid fails. A RoseWater HUB is already supplying the circuits it serves, so an outage causes no gap at all and nothing blinks or reboots.

What is online double conversion?

What is online double conversion?

Online double conversion means incoming power is converted to DC and then rebuilt as a fresh AC sine wave before it reaches your panel. Because the output is rebuilt all the time, problems on the incoming line do not pass through. RoseWater HUBs run this way continuously and have no eco mode that bypasses it.

What is the difference between a surge and a sag?

What is the difference between a surge and a sag?

A surge is extra voltage and a sag is missing voltage. A surge protector can divert extra energy to ground, but nothing can divert power that is not there, so only stored energy such as a battery can fill a sag.

Does a whole house surge protector condition power?

Does a whole house surge protector condition power?

No. A whole house surge protector diverts voltage spikes, which is useful, but it does nothing for sags, brownouts, electrical noise or outages. A RoseWater HUB includes surge and lightning protection and handles those other problems too.

Do I need a HUB if my power seems fine?

Do I need a HUB if my power seems fine?

You may already be seeing the symptoms without connecting them to power. Lights that flicker or dim, displays that wake up on their own, equipment that needs a reboot and LED bulbs that fail early are common signs of poor power quality. Outages are only the part you notice.

Does the HUB clean generator power too?

Does the HUB clean generator power too?

Yes. A HUB conditions power from every source it is connected to, so generator power gets the same surge protection, regulation and filtering as grid power before it reaches your panel.

Where to go next

Build Your Power Plan

Choose what should stay on and get a first sizing for your home.

HUB vs generator vs battery

A side-by-side comparison of the main backup options.

The RoseWater lineup

HUB20, HUB40 and 3-phase systems, with full specs.

Whole House Power Conditioning

What dirty power is, why lights flicker and equipment reboots, and how conditioning at the panel fixes it.

Whole House Surge Protection Explained

What a panel surge protector stops, what it misses, and where power conditioning picks up.

What Is a Whole House UPS?

Transfer time, online double conversion, and how a whole-home UPS differs from a home battery.

Backup power FAQ

Straight answers on batteries, generators, solar and installation.

Talk to us

Call (781) 333-8003 or send a note and we will set up a consultation.

What Should Stay On When the Grid Goes Down?

Build a Power Plan for your home in a few minutes. We review it, confirm sizing on a site visit, and design a RoseWater system around the way you live.

Build Your Power Planor call (781) 333-8003Book a consultation