40kVA UPS in Kenya: Price, Full Load Current and Which SIEL to Choose

A 40kVA UPS in Kenya protects up to 40 kW of critical load, such as a full server room, a hospital’s critical circuits or a bank head office. At Encom, the two options are the SIEL Safepower S 40K and the SIEL Safepower Evo HF 40K, and both need a three-phase supply. We quote each one per project, because the battery bank for your backup time sets most of the price.

Prices and specs checked on 21 October 2026.

Key takeaways

• Both SIEL 40kVA models deliver the full 40 kW, because their output power factor is 1.
• At 400 V three-phase, a 40kVA UPS draws about 58 A per phase at full load.
• The Safepower S 40K weighs 73 kg in a 250 mm wide cabinet, while the Evo HF 40K weighs 272 kg with its internal batteries.
• Kenyan consumers averaged 8.39 hours of outages a month, against an EPRA target of 1.5 hours.
• Power caused 54% of impactful data centre outages in the Uptime Institute’s 2025 analysis.

How much does a 40kVA UPS cost in Kenya?

There is no fixed shelf price for a 40kVA UPS in Kenya, because the batteries change the total so much. For example, 10 minutes of backup needs far fewer battery blocks than two hours does. So we quote each SIEL unit once 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 runs more units in parallel.
• The battery bank. VRLA blocks in external cabinets, or lithium (LiFePO4) when you choose the Evo HF.
• Installation. Cabling and breakers, as well as a maintenance bypass switch if your site wants one.
• Monitoring. SNMP or relay cards when you want the UPS on your network or building system.

Since SIEL units come on order, your quote also covers the lead time. Encom is the only SIEL retailer in Kenya and East Africa, so the quote comes straight from us.

What can a 40kVA UPS run?

A SIEL 40kVA UPS can carry up to 40 kW of running load, because its power factor is 1. In practice, that covers a server room, a call centre floor, a bank head office, a hospital’s theatre and ICU circuits, or the control systems of a production line.

For context, average server racks still draw below 8 kW, according to the Uptime Institute’s 2024 survey. So one 40kVA unit can protect about four average racks and still leave headroom. However, always size from your measured load, not from averages. We usually suggest you run the UPS at about 70 to 80% of its rating, so you have room to grow.

Air conditioners, water heaters and big motors belong on the generator instead. Their start-up surges eat UPS capacity fast, and they rarely need clean power.

Why do Kenyan sites need a 40kVA online UPS?

Kenyan sites need one because the grid still drops out often, and a site of this size loses real money each time. Kenyan consumers averaged 8.39 hours of outages a month, against EPRA’s target of 1.5 hours, according to People Daily’s report on EPRA’s latest statistics. At the same time, demand rose 8.25% in the second half of 2025.

Downtime is costly too. In the Uptime Institute’s 2025 outage analysis, power caused 54% of impactful outages. Also, 54% of operators said their latest serious outage cost over $100,000, while 20% put it above $1 million. As Uptime’s CTO Chris Brown said, power is “pretty unforgiving.”

So when stima imeenda, an online UPS keeps the load running with no switchover gap at all. That is why both SIEL models use online double conversion.

40kVA UPS to kW: why power factor matters

A 40kVA UPS only gives you 40 kW when its output 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 40kVA model of that kind gives only 32 or 36 kW. In contrast, SIEL gives both the Safepower S 40K and the Evo HF 40K an output power factor of 1. That is, 40 kVA equals 40 kW, which you can check on each product page.

What is the full load current of a 40kVA UPS?

At 400 V three-phase, a 40kVA UPS draws about 58 A per phase at full output. The standard three-phase formula is I = kVA x 1000 / (1.732 x V), so 40,000 / (1.732 x 400) gives 57.7 A.

• Similarly, at 380 V it rises to about 61 A per phase.
• Likewise, at 415 V it drops to about 56 A per phase.
• The input side draws a little more while the batteries recharge, so allow a margin on the input breaker.

Unlike the 10K and 20K models, SIEL lists no single-phase version of its 40K units. As a result, you need a three-phase supply from KPLC before you order one.

What cable size does a 40kVA UPS need?

Cable size depends on run length, the installation method and the breaker, so a licensed electrician should confirm it on site. Still, the 58 A per phase figure gives them the starting point. In Kenya, this work falls under EPRA’s Electrical Installation Work Rules, which also cover licensing for electricians and contractors.

SIEL Safepower S 40K vs Evo HF 40K

Both are online double conversion units (VFI-SS-111 under IEC EN 62040-3). However, they suit different rooms.

When to choose the Safepower S 40K

Pick the Safepower S 40K when floor space is tight or you already plan a battery room. Its cabinet is only 250 mm wide, so it fits a narrow comms room. It also brings a 7 inch touchscreen, LAN, Modbus, dry contacts, remote emergency power off and a diesel mode input. In addition, its charger gives up to 20 A, which helps refill a large battery bank after a long outage.

When to choose the Evo HF 40K

Pick the Safepower Evo HF 40K when you want batteries inside the cabinet, lithium, or room to grow. Up to eight units can run in parallel, so you can add a second 40K later for N+1 redundancy. 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.” Also, it carries 103% load with no time limit.

How many batteries does a 40kVA UPS need?

A SIEL 40kVA UPS runs on a string of 12 V battery blocks split around a centre point. The Evo HF 40K takes 40 blocks per string (20 + 20), and it has room inside for up to three strings of 9Ah blocks. Meanwhile, the Safepower S 40K takes an adjustable string of 32 to 40 blocks, all in external cabinets.

For longer backup, we then add more strings or bigger blocks. As a result, the battery count in your quote follows the minutes you need, not just the UPS size.

How long will a 40kVA UPS run on battery?

Backup time depends on your real load and your battery bank, so there is no single figure. For instance, a 40kVA UPS at half load runs far longer than one at full load on the same batteries. Lead-acid blocks also give less capacity when you drain them fast, so we work from the battery maker’s discharge tables.

• With a generator: you only need enough time for the generator to start and take the load, plus a margin. We usually suggest 10 to 15 minutes.
• Without a generator: plan instead for your longest likely outage, which in parts of Kenya can run for hours.

Kenya Power also posts planned maintenance outages almost daily on its official X account. So check how long those usually last in your area before you choose a runtime.

Does a 40kVA UPS work with a generator?

Yes, and both SIEL 40K models suit generator sites well. Their input power factor is 0.99, with current distortion (THDi) of 3% or less, which means less stress on the generator. The Safepower S also accepts 208 to 478 V and 40 to 70 Hz at its input, so it rides through generator swings.

Still, size the generator from a proper report. Nicholas Paolo of MTU Onsite Energy put it plainly: “we do not recommend using the 1.5 times the UPS load rule of thumb to assign a generator capacity.” Instead, give your generator supplier the UPS load, its rectifier type and its recharge rate.

Where should you install a 40kVA UPS?

Put it in a cool, dry, clean room near your distribution board. SIEL rates both models 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.

Batteries age faster in heat, so air conditioning in the battery room pays off, especially in Mombasa or Kisumu. Finally, check the floor and the access route before delivery day, because the Evo HF 40K weighs 272 kg with its batteries.

Getting a 40kVA UPS quote in Kenya

To quote a 40kVA UPS in Kenya quickly, we need your load in kW (or an equipment list), 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 20kVA SIEL units or the Safepower S 30K. On the other hand, if it is bigger, the Safepower S 60K and Evo HF 60K are the next step up. For the wider picture, read our SIEL range explained, learn how to choose a three phase UPS, or see redundancy and batteries for data centres. You can also browse our full critical and industrial UPS range.

Frequently asked questions

Prices and buying

Sizing and power

Batteries and backup time