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Holt Systems

Power failure alarm for sheds: a text the minute the mains goes

We fit a mains sensor and gateway on their own batteries, so the alert still reaches your phone when the shed goes dark.

  • WatchesMains, each phase, generator run
  • You getA text to two or more people
  • Works withoutSite wifi and mobile coverage
Get a quote for a shed power alarm See the SMS alerts or call 07 2150 3666
Shed 2 alerts

  1. 2:03 am

    Shed 2 mains lost for 2 min. Phase 2 down. Fans off. Check supply.

  2. 2:08 am

    Shed 2 no generator run signal after 5 min. Sent to all nominated people.

  3. 2:41 am

    Shed 2 mains restored after 41 min. All 3 phases present. Fan current normal.

Example alerts from this system

about 179,000

Broilers died at a Helensville farm in 2019 after a second power cut and a generator relay fault.

Source: NZ Herald

about 500

Pigs were reported dead at Grong Grong NSW after the shed lost ventilation.

Source: Farm Online

36 hours

Without milking, udder cells begin to shut down, according to Dairy Australia.

Source: Dairy Australia

The power drops at 2 am and the shed turns into a sealed box

A power failure alarm for a shed has to work when the power doesn't. A tunnel shed without fans heats up fast, with heat stress reported within about 10 minutes (University of Delaware).

At Helensville in 2019 the generator relay failed and the alarm router had no battery backup, so nobody got a call. At Grong Grong, a security company saw the fault but couldn't reach anyone on call.

  • A router alarm dies with the mains unless it has a battery backup.
  • The power company's text tells you about the network, not your tripped breaker.
  • One dropped phase keeps the lights on while motors overheat.

The same outage, with and without a text

Without monitoring

  1. 2:00 amMains fails. Fans stop. The generator doesn't start.
  2. 2:10 amHeat stress can start in the shed.
  3. 5:30 amYou find the shed dark on your rounds.

With monitoring

  1. 2:00 amMains fails. The sensor keeps sending on its battery.
  2. 2:03 amYour phone buzzes. Your second person's too.
  3. 2:08 amNo generator signal, so everyone listed gets a text.

How a battery-backed power failure alarm works

Power failure alarm: shed plan and outage time strip Plan of a 150 metre tunnel ventilated broiler shed. Mains arrives at a switchboard with a changeover to a standby generator. The end-wall fans, the shed controller and the shed router are drawn dashed grey because they lose power in an outage. A mains sensor with its own battery, a gateway battery box and a Starlink dish on 12 volt DC are drawn orange because they keep running, and they send an SMS to phones. Air inlets are at the far end of the shed. Below the plan is a time strip in minutes after the mains is lost. Top lane: the generator starts, an SMS is sent at about 3 minutes, and the generator is carrying load by 15 minutes, the restoration target in guideline GA 7.7. Bottom lane, the Helensville New Zealand case of 2019: the generator relay fails and the alert path is lost, so no SMS gets out and only the site silent alert fires, at 50 minutes. Plan of a 150 m tunnel shed Mains in Switchboard and changeover Standby generator Loses power Keeps running Power feed Mains sensor own battery Gateway battery box Starlink 12 V DC SMS to phones End-wall fans Shed controller Inlets Shed router Air flow 150 m Minutes after mains is lost Mains lost at 0, generator starts Mains out Generator carrying load SMS, about 3 min (target) GA 7.7: power or emergency ventilation back in 15 min Helensville case, NZ, 2019 Generator relay fails, alert path lost No SMS gets out, so the cloud can only see the site go silent Site silent alert at 50 min
Plan of a 150 m tunnel ventilated broiler shed showing what loses power in an outage and what keeps running, with timings for a generator that starts and for the Helensville case, where the relay fails and the alert path is lost.
  1. 1

    A sensor watches the mains

    A battery-backed sensor on the incomer side of the switchboard keeps sending after the mains drops.

  2. 2

    Radio to the gateway

    LoRaWAN (long range wide area network) radio carries each reading to a gateway on its own battery box.

  3. 3

    Starlink or 4G sends the text

    Starlink runs at 12 V DC from the same battery. Where 4G signal is good, we use that instead.

  4. 4

    Silence is an alert too

    If the gateway stops reporting, the cloud raises a site silent alert after 50 minutes.

What we fit in the shed and at the gateway

  • Mains loss sensor

    Watches the supply at the switchboard and keeps sending when it drops.

    Own battery

  • Phase and generator inputs

    Reads a phase relay and the generator run contact, so one lost phase or a failed start gets reported.

    Alert in 1 to 2 min

  • Fan feeder clamp

    Shows whether the fans are pulling current, even when the mains is healthy.

    Alert after 2 min low

  • Gateway battery box

    Collects every sensor by radio and runs through the outage.

    Heartbeat every 20 min

  • Starlink backhaul

    Sends the text out with no site wifi or mobile signal needed.

    12 V DC, 4G if signal's good

What lands on your phone when the mains goes

Shed 2 mains and fan current

Dashboard view

Mains
Lost
Generator run
Not running
Fan feeder
0 A
Gateway battery
OK
0 19 38 Fan current alert level 1:302:002:102:303:00 A
Example fan feeder current for a shed. We set the levels for your fans.

Today versus with a power failure alarm

TopicTodayWith monitoring
Finding outRounds, a siren nobody hears, or a neighbour's callA text to your phone within minutes
Router alarmsDies with the mains unless it has a batterySensor, gateway and Starlink run on their own batteries
One lost phaseLights stay on, motors overheatA phase relay triggers the alert

On a poultry, pig or dairy site

We walk your switchboard, supply type and generator changeover.

Queensland's pig code (sections 12 and 13) asks for an effective backup ventilation system, or twice daily checks on naturally ventilated sheds. This alarm sits beside the backup. A dairy's generator call has to come before the next milking.

Running a generator? Add a poultry shed generator alarm. Worried about a tripped breaker? See shed breaker trip alert.

Broiler chickens filling the floor of a long tunnel-ventilated shed
Illustrative photo. Photo: Pexels

What it costs

We set a fixed price after a short scoping call or a site visit. It depends on how many supplies and sensors, how far the gateway is from them, and how it gets out. After handover you can add an ongoing support plan.

Get a quote for a shed power alarm

The fixed price covers

  • Sensors on each supply you want watched
  • Gateway, battery box and Starlink or 4G backhaul
  • Installation and electrical work under QLD Electrical Contractor Licence 1513082
  • Alert set-up, who gets the text and in what order
  • Commissioning and training
  • Ongoing support plan: batteries, faults, alert tuning and extra sensors

What this alarm won't do

  • It doesn't replace your back-up power, controller alarm or response system. It's a second path, not a control or certified safety system.
  • LoRaWAN sends small readings, not a live feed, and stops outside gateway range.
  • The gateway battery isn't endless. On an assumed 12.8 V, 100 Ah battery, a 4G gateway at 8 W runs about 5 days and Starlink at 30 to 45 W about 23 to 34 hours.
  • Texts only reach phones with coverage. Your nominated people act on the alert.

With you every step

How the five stages go on a shed power alarm, from the switchboard walk to proving the text on battery alone.

  1. 1

    Discovery

    We walk the switchboard, supply type and generator changeover, then test radio coverage and the Starlink or 4G signal.

  2. 2

    Design

    You get a written scope: what's watched, the delays, who gets texts, the backhaul and the weekly test.

  3. 3

    Build and test

    We build the sensors, battery box and alert rules off site and run the gateway on battery alone.

  4. 4

    Install and commission

    We do the electrical work under Licence 1513082, then simulate a mains loss and time the text on your phones.

  5. 5

    Ongoing support

    You get the alert list and test log, the dashboard goes live, and we support it from there.

Why Holt Systems

We design, install and commission every system ourselves, then look after it with an ongoing support plan. Monitoring supplements the site's own control, protection, fire and safety systems; it does not replace them.

Alerts
SMS to any phone, no app
Based in
Brisbane, QLD
Electrical licence
QLD 1513082
After install
Ongoing support plans
Call
07 2150 3666

Power failure alarm questions

Will a power failure alarm still work when the power is off?

Only if every link has its own supply. The mains sensor has its own battery, the gateway runs from a battery box and Starlink runs at 12 V DC from it. The battery is finite, so the cloud raises a site silent alert if the gateway stops reporting.

Can it tell me when only one of three phases has failed?

Yes, where a phase monitoring relay is fitted at the incomer and wired to the sensor's dry-contact input. We fit it under QLD Electrical Contractor Licence 1513082. Guideline GA 7.7 asks for detection of a failure in any phase.

Can I be told the generator did not start?

Yes. A dry contact from the generator controller or changeover gives a run signal. If the mains is lost for 3 to 5 minutes with no run signal, every nominated person is texted. Changeover work and testing stay with a licensed electrician.

How do I know the alarm itself is still working?

A test SMS goes out at a fixed weekly or monthly time and is logged. The sensor also sends a heartbeat, and silence for 2.5 times its interval raises a site silent alert.

Does it replace the controller alarm or the generator?

No. Your existing back-up power, controller alarm and response system stay in place, and this is an independent second path. It isn't a control system or a certified safety system. Your nominated people respond, and we support the system behind them.

Does my old GSM alarm still work after the 3G shutdown?

Only if it uses 4G. Telstra and Optus switched 3G off on 28 October 2024, according to business.gov.au, so a 3G-only unit no longer connects. Check its network generation and what it does when one phase fails before you rely on it.

Sources

  1. New requirements for chicken meat producers, Agriculture Victoria
  2. Australian Animal Welfare Standards and Guidelines for Poultry (2022), Department of Agriculture, Fisheries and Forestry
  3. Poultry welfare code, Business Queensland
  4. Animal Care and Protection Regulation 2023, Schedule 2 (pigs), Queensland Government, Office of the Queensland Parliamentary Counsel
  5. Alarm failure contributed to 179,000 chicken deaths at West Auckland broiler farm, NZ Herald
  6. 500 pigs baked to death, Farm Online
  7. Developing a Catastrophic Mortality Plan for Broiler Farms (2015), University of Delaware Cooperative Extension
  8. Preparing for power outages (dairy fact sheet, 2015), Dairy Australia (hosted copy)
  9. Submission to QCA: Review of Guaranteed Service Levels (26 March 2018), Queensland Farmers' Federation
  10. The 3G network is closing down, business.gov.au
  11. Permanently connected generators, Queensland Electrical Safety Office

Get a quote for a shed power alarm

Tell us what you need to watch and where. We confirm the sensors, gateway location and alert recipients, then give you a fixed price.

Or email hello@holtsystems.com.au

Your details are handled in accordance with our privacy policy.

  1. 1

    Tell us about the site

    A few lines on the assets, distances and what you need to know about.

  2. 2

    A call to scope it

    We confirm the sensors, gateway location and alert recipients, and whether a site visit is needed.

  3. 3

    Fixed price

    You receive a defined scope and a fixed price before any work starts.

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