The Switchboard And Backup Power
In a dwelling where a hoist, a bed or a ventilator is in use, a power outage is not an inconvenience. The question is which circuits have to stay on and what keeps them on.
Does supported accommodation need backup power?
It depends on what the residents rely on. Where a ceiling hoist, an adjustable bed, refrigerated medication or clinical equipment is in use, the loss of supply has a consequence, so those circuits are identified and a backup arrangement is specified for them rather than for the whole dwelling.
A switchboard is the least discussed element in a dwelling and the one that limits what can be added later.
In supported accommodation it carries more than a house does, and some of what it carries cannot stop.
Size it for what comes later
The equipment a resident uses changes, usually by increasing. A hoist is installed, a second one is added, an air conditioner goes into a bedroom, a bed is replaced with a powered one.
Each of those is a circuit. A switchboard with no spare capacity means every change is a board upgrade, which is expensive and disruptive in an occupied dwelling.
So the board is sized with spare ways and spare capacity from the start, which costs very little at build and is the difference between a change taking a day and taking a week. That is the same reasoning as [designing for changing resident needs](/blog/designing-for-changing-resident-needs).
Separate the circuits properly
More circuits rather than fewer, which matters for two reasons.
**Fault isolation.** A failure on one circuit does not take out the whole dwelling. In a shared dwelling that means one resident's room rather than everybody.
**Leakage headroom.** Safety switches detect current leaking to earth, and small leakages across many devices accumulate. A heavily loaded circuit with a lot on it sits closer to the trip threshold, so a single new fault takes it out.
Which argues for the hoist on its own circuit, the medical equipment on its own, and the bedrooms separated rather than looped.
Identify what cannot stop
This is the design conversation, and it is had with the accommodation provider rather than assumed.
**A ceiling hoist,** where a resident is being transferred when the supply fails. Most hoists carry a battery and an emergency lowering function, and whether that is sufficient depends on the resident. The structural and power provision for them is in [ceiling hoists and structural provision](/blog/ceiling-hoists-and-structural-provision).
**A powered bed,** where position affects breathing or pressure care.
**Refrigerated medication.**
**Clinical equipment,** including anything respiratory, which is the clearest case for a backup supply.
**Communication and call systems,** so a resident can still call for assistance. The rest of that layer is in [assistive technology in supported accommodation](/blog/assistive-technology-in-supported-accommodation).
**Emergency and egress lighting,** which has its own requirement under the building code regardless of the resident profile.
What provides the backup
**Equipment batteries,** which cover minutes to hours and are the first line for hoists and beds.
**A battery system with an essential circuits arrangement,** where a defined set of circuits is supported and the rest are shed. The practical answer on most sites with solar already specified, and it sits with [solar, batteries and all-electric dwellings](/blog/solar-batteries-and-all-electric-dwellings).
**A generator connection,** where the outage risk is long rather than short, which is the regional and remote case described in [modular for regional and remote sites](/blog/modular-for-regional-and-remote-sites).
**An uninterruptible supply** for specific equipment that cannot tolerate even a brief interruption.
Which one applies depends on the resident and the location, and the decision is specified rather than defaulted.
Position and access
The board has to be reachable for isolation in an emergency and for a resident or support worker to reset a tripped circuit.
Which means it is not in a locked plant room on the far side of the site, and it is not at a height nobody in the dwelling can reach. Labelled clearly, in plain language rather than only in trade shorthand, so somebody who does not work in the building can find the right switch.
It is built in the factory
The board, the circuits and the provisions are installed when the module is built, which means the capacity conversation happens in design documentation.
Adding capacity later means a board change in an occupied dwelling. Allowing for it at build is a line item. The sequence that forces that decision early is set out in [the eight design stages explained](/blog/the-eight-design-stages-explained).
MADEmodular / MADEbetter.
MADEmodular / MADEbetter.