20kVA UPS in Kenya: Price, Backup Time and Which SIEL to Choose

A 20kVA UPS in Kenya suits sites that need to protect up to about 20 kW of equipment, such as a small server room, a bank branch or a clinic. At Encom, the two 20kVA options are the SIEL Safepower S 20K and the SIEL Safepower Evo HF 20K. Both are online double conversion units, and we quote them per project because the battery backup you need sets most of the price.

Prices and specs checked on 19 October 2026.

Key takeaways

• Both SIEL 20kVA models deliver a full 20 kW, because their output power factor is 1.
• At full load, a 20kVA UPS carries about 29 A per phase when the supply is 400 V three-phase.
• The Safepower S 20K reaches up to 96.5% efficiency online, while the Evo HF 20K reaches up to 96.6%.
• Kenyan electricity users face about 8.39 hours of blackouts a month, according to EPRA data.
• Encom supplies SIEL units on order, so every 20kVA UPS quote includes the battery bank sized for your runtime.

How much does a 20kVA UPS cost in Kenya?

There is no single shelf price, because the batteries change the total so much. For example, a 20kVA UPS with 10 minutes of backup needs a far smaller battery bank than one that must run for an hour. So we price each SIEL unit after we know your load and runtime. Also, all our prices exclude VAT.

In particular, four things set the final figure:

• The model. Safepower S or Safepower Evo HF, since the Evo HF scales further.
• The battery bank. Standard VRLA batteries, or lithium (LiFePO4) when you choose the Evo HF.
• The output. Three-phase output, or single-phase output (3/1) when your loads are single-phase.
• Installation. Cabling and breakers, as well as any bypass switch your site needs.

What can a 20kVA UPS run?

Because its power factor is 1, a 20kVA SIEL UPS can carry up to 20 kW of running load. For example, that covers a small server room, a network core with its cooling controls, a bank branch, a clinic’s critical circuits or a small production line’s control systems.

For context, average server racks still draw below 8 kW, according to the Uptime Institute’s 2024 survey. So one 20kVA unit can protect about two average racks and still leave headroom. However, always size from your real load, not from averages.

20kVA UPS to kW: why power factor matters

Note that a 20kVA UPS only gives you 20 kW when its power factor is 1. Schneider Electric puts it simply: “Watts is the real power drawn by the equipment, while volt-amps are called the apparent power.” The ratio between them is the power factor.

Many UPS makers rate their units at 0.8 or 0.9, so a 20kVA model of that kind delivers only 16 or 18 kW. In contrast, SIEL rates both the Safepower S and Evo HF at an output power factor of 1. That is, 20 kVA equals 20 kW, which you can check on the product pages.

What is the full load current of a 20kVA UPS?

At 400 V three-phase, a 20kVA UPS draws about 29 A per phase at full output. The standard formula is I = kVA × 1000 / (√3 × V), so 20,000 / (1.732 × 400) gives 28.9 A.

• Similarly, at 380 V it is about 30 A per phase.
• Likewise, at 415 V it drops to about 28 A per phase.
• With a single-phase 230 V output (the 3/1 version), the output current rises to about 87 A, because one phase carries all the load.

These numbers help you plan breakers and cables before installation day. Still, cable size also depends on run length and installation method, so have a licensed electrician confirm it. In Kenya, electrical installation work falls under EPRA’s Electrical Installation Work Rules, which also cover licensing for electricians and contractors.

SIEL Safepower S 20K vs Evo HF 20K

When to choose the Safepower S 20K

Pick the Safepower S 20K when floor space is tight. Its cabinet is just 250 mm wide, yet it still has room for internal batteries. It also adds a 7 inch touchscreen, plus LAN, Modbus, dry contacts and a diesel mode input for sites with a generator.

When to choose the Evo HF 20K

Pick the Safepower Evo HF 20K when you plan to grow or want lithium batteries. Up to eight units can run in parallel, so you can add capacity later or run two units as N+1. In SIEL’s words, the range is “capable of providing clean energy to the connected load, without interruption, regardless of the conditions of the supply network.”

How many batteries does a 20kVA UPS need?

A SIEL 20kVA UPS uses a string of 12 V battery blocks split around a centre point. The Evo HF 20K takes 40 blocks per string (20 + 20), and it has internal space for up to three strings of 9Ah batteries. Meanwhile, the Safepower S 20K takes an adjustable string of 32 to 40 blocks.

For longer runtimes, we then add external battery cabinets with bigger blocks or more strings. As a result, the battery count in your quote depends on the minutes you need, not just on the UPS size.

How long will a 20kVA UPS run on battery?

Runtime depends on your load and your battery bank, so there is no fixed figure. For instance, a 20kVA UPS at half load runs much longer than one at full load on the same batteries.

Battery maths is also not linear. A Vertiv paper for the Battcon conference notes that “a lead-acid battery will deliver less capacity in amp-hours at a higher rate, than it will at a lower rate.” That is why we size batteries from the maker’s discharge tables instead of simple division.

Here is how to choose your target:

• With a generator: UPS batteries have traditionally been sized for 15 minutes, since the UPS only bridges the gap until the generator takes over.
• Without a generator: plan instead for your longest likely outage. Kenyans face about 8.39 hours of blackouts a month, according to EPRA data reported by People Daily, and some single outages run for hours.

20kVA UPS size, weight and placement

Both SIEL 20kVA units are floor-standing towers, so plan a cool, dry spot near your distribution board. The Safepower S 20K weighs 171 kg with internal batteries, but only 64 kg without. In comparison, the Evo HF 20K weighs 265 kg with batteries and 105 kg without.

SIEL rates both for 0 to 40 °C and up to 95% humidity, as long as there is no condensation. Since the cabinets are IP20, keep them indoors and away from dust. Finally, check the floor and the access route before delivery day.

Getting a 20kVA UPS quote from Encom

In order to quote quickly, we need your load in kW (or an equipment list), your supply type, the runtime you want and whether you have a generator. Then we come back with the right model and battery setup. Request a quote on WhatsApp on +254 714 962 072, or Email us.

However, if your load is smaller, see our guide to the 10kVA online UPS. On the other hand, if it is bigger, the Safepower S 30K and Evo HF 30K are the next step up. In addition, for the wider picture, read how to choose a three phase UPS or browse our SIEL UPS range.

Frequently asked questions

20kVA UPS price and buying

Sizing and power

Batteries and backup time