Prepare
- Document essential functions, operating periods, resources and applicable component limits before work starts.
- Isolate energy sources, verify protective devices and identify work reserved for qualified trades.
A · Foundations of self-reliant living · 12–18 MIN
Define which services must work independently and for how long
In this lesson, you determine what “Define which services must work independently and for how long” must deliver in practice. You check the site conditions and the limits of the equipment, then record the result, the available reserve and a safe alternative.
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Lesson guide
Procedure
Prepare, complete each step and verify the result.
Apply
- Complete “Step 1” and record each value together with its unit and operating condition.
- Before continuing, decide which warning signs require you to stop and which safe alternative remains available.
Verify
- Purpose, operating period and limits for define which services must work independently and for how long recorded
- Relevant input and output values measured with units
- Connection order and polarity checked against the data sheets
If the plan does not work
Adapt safely
- Reduce demand or test a smaller isolated system before increasing capacity.
- Use a documented safe fallback when a component, resource or measurement is uncertain.
Detect and correct errors
- A value without unit or operating condition must be measured again and recorded.
- On heat, smell, vibration, leakage or unstable readings: stop, isolate and identify the cause before restart.
Learning objectives
- For power, water, heat and food, write down what must keep working and for how many days.
- Record the required supplies, resupply options, maintenance work and the person able to operate each system.
- Measure the result and compare it with the permitted limits
What to check
For power, water, heat and food, write down what must keep working and for how many days. Record the required supplies, resupply options, maintenance work and the person able to operate each system.
TECHNICAL DRAWING 1/1
Physical system boundary
For power, water, heat and food, write down what must keep working and for how many days. Record the required supplies, resupply options, maintenance work and the person able to operate each system.
Dependencies and limits
Start with a written inventory of people, essential functions, resources and the longest tolerable interruption. Separate comfort from health and safety.
Plan in the right order
Work in layers: reduce demand first, size stocks and generation second, then test an independent fallback. Record every figure with date, measurement method and assumptions.
Check and safeguard operation
Judge each solution by capacity, duration, resupply and operability. A system is only as resilient as its scarcest resource and the person operating it under pressure.
Worked calculation or decision
“Seven days of drinking water and lighting” can be tested. “Indefinitely self-reliant” is not a useful plan without winter figures, resupply and spare parts.
PROCEDURE
Carry out the lesson step by step
- 01 · Step 1
For power, water, heat and food, write down what must keep working and for how many days.
- 02 · Step 2
Record the required supplies, resupply options, maintenance work and the person able to operate each system.
- 03 · Check the result
Measure the result, record its unit and operating condition, and compare it with the permitted limit for the component before continuing.
Materials and tools
- Demand and risk log
- Meter or manufacturer data
- Calendar and maintenance list
- Labelled reserve containers
Safety and stop conditions
- Never make essential medical equipment depend on one DIY solution.
- On gas smell, smoke, abnormal heat or damaged wiring, shut down, keep clear and call qualified help.
Typical mistakes
- Using a stated value for “Define which services must work independently and for how long” without checking its unit and the conditions under which it applies
- Buying or connecting components before confirming that they are compatible and adequately protected
- Assuming nominal capacity, peak output or one favourable measurement will be available continuously
- Continuing to operate despite unusual heat, smell, vibration, leakage, contamination or unstable readings
Final checklist
- Purpose, operating period and limits for define which services must work independently and for how long recorded
- Relevant input and output values measured with units
- Connection order and polarity checked against the data sheets
- Losses, temperature, seasonal effects and reserve included
- Safe shutdown and isolation tested before full load
- Result, unusual observations and next inspection recorded
DECISION CHECK
A measured value for “Define which services must work independently and for how long” differs from the plan and a warning sign appears. What should you do?
- Average it with the best earlier reading
- Stop the system, secure the affected section, find the cause and repeat the test under controlled conditions
- Increase the fuse rating or alarm threshold
Show answer
Correct answer: Stop the system, secure the affected section, find the cause and repeat the test under controlled conditions
Use this example for comparison: “Seven days of drinking water and lighting” can be tested. “Indefinitely self-reliant” is not a useful plan without winter figures, resupply and spare parts. Do not resume operation until the cause of the warning and the relevant limit have been clarified.