A standby generator that never runs still needs exercise under load, fluid checks and battery care. Follow the engine OEM hour intervals for oil, filters and coolant, and keep a written log. Missed services are the main reason “new” sets fail on the first long outage night.
Why this decision matters
A standby generator that never runs still needs exercise under load, fluid checks and battery care. Follow the engine OEM hour intervals for oil, filters and coolant, and keep a written log. Missed services are the main reason “new” sets fail on the first long outage night. Buyers who skip structured sizing or compliance checks pay twice: once for the wrong unit, and again for downtime, fuel waste or a failed insurance claim.
AGP Generators engineers treat every enquiry as a load and site problem first, a product second. The notes below are the same framework we use on commercial RFQs across South Africa and SADC.
Practical method
Step-by-step
Start with a written load list: running watts, starting watts, duty cycle and which loads are truly critical. Convert watts to kVA using power factor (0.8 is the commercial default unless you know otherwise).
Apply site factors next — altitude derate, ambient temperature, fuel quality and whether the set will see prime hours or true standby. Only then shortlist engine brands and canopy types.
Validate with our Fuel consumption calculator and a specialist review before you issue a purchase order. Catalogue pages for the 100 kVA Perkins silent and 250 kVA Perkins silent show real price bands excl. VAT to sanity-check budgets.
- Record running and starting loads separately for motors and compressors.
- Separate essential vs shedable circuits so you do not oversize the set.
- Confirm phase (single vs three) against the DB and utility supply.
- Document who owns installation, CoC and first service.
Reference data
Use the table as an indicative planning aid, not a substitute for a site assessment. Prices and fuel figures move with diesel wholesale rates and exchange rates — we re-verify commercial quotes at order stage. Last updated 2026-05-20.
Common mistakes
Copying the kVA of a failed set without measuring today’s load. Ignoring motor starting. Buying open-frame units for estate boundaries. Skipping changeover and earthing design. Assuming “silent” means inaudible indoors.
How AGP helps
We size, supply, install and maintain diesel and petrol generators from 2.2 kVA to 1000+ kVA. Request a quote with your load list, or call +27 41 007 0618. For hybrid and long-hour sites, ask about diesel-solar controllers that keep engines in an efficient band.
Data table
Typical service rhythm (confirm with OEM)
| Interval | Actions | Notes |
|---|---|---|
| Weekly | Visual, battery, exercise run | Load bank if light site load |
| 250 h / 6 mo | Oil & filters | Earlier in dusty sites |
| 500 h | Fuel filters, belts, coolant check | Water-in-fuel bowl |
| 1000 h | Major inspection | Valve/injector per OEM |
| Annually | Full function test + log review | Update CoC if altered |
Figures are indicative. Last updated 20 May 2026.
Frequently asked questions
How often should a standby set run?
Weekly exercise under load is a common best practice.
Can I skip oil changes if hours are low?
Time-based intervals still apply — oil ages even at rest.
Battery failures?
Leading cause of no-start; test and replace on schedule.
Wet stacking?
From chronic light load — use load banks or combine loads.
Do you offer contracts?
Yes — ask Service about scheduled maintenance and 24/7 call-out tiers.
Related tools: Fuel consumption calculator · All insights
Related sizes, categories and services: 100 kVA generators, 250 kVA generators and petrol generators.
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