Testing Our Backup Infrastructure

kraftech backup generator
The Kraftech KT6500W generator

In any backup system, it is necessary to test backups, and infrastructure.  We do this at least once a month.

Backup Infrastructure Testing for Resilience

Today, we are performing wider tests, we are simulating an extended power failure to our rack, and as I write this we are running on our Kraftech KT6500W backup generator.  We chose this 6hp four stroke generator carefully for it’s quiet running, around 68dB at 7meters, extended run time of 11 hours, and that it has three 2.5KVA sockets.  We can simply plug each of our APC SmartUPS 2200 rack mounted UPS into each of the power outputs, albeit with their sensitivities set to low.  Each UPS is only 30% loaded for resilience and longer run times.

Kraftech KT6500W Test Results

Each time we start our generator, for the first few minutes, our generator appears to generate power at 234volts AC and a 54Hz.  We notice that the rack containing the RKive.IT vaults continues to run on their UPS batteries until the generator warms up and slows down slightly.  As this happens, the voltage frequency stabilises at 51Hz, close enough for the UPS to switch from battery to the power fed from the generator.  This seems to happen each time we start the generator, and we have to note that there must be a few minutes left in the UPS batteries to be able to switch over without needing an outage.  Once warm, the Kraftech KT6500W generates 230volts at 51Hz quite well and is stable.  More importantly, the UPS’s like the power that is being generated.

Extended Power Outage Run Time

We plan to run on generator for two hours today, simulating that our power has failed.  The fuel tank is full, and when we shut the backup generator down, we will be able to take a reading of how much fuel it has used.  This test will allow us to monitor fuel usage and additionally allow us to estimate how much fuel we would require for a 24 hour outage.  As the power company will most likely restore a loss of power within 4 hours, we are looking to cater for a continuous run time of 24 hours, ie six times longer.  The probability of needing to run longer would be very slim indeed.  Our worse case scenario would be needing to go out to get fuel to refuel.  We are running on unleaded fuel.

It is really good to know that all of our systems and procedures are working just fine.  Should a failure occur, we are confident a customer would not notice a change of power supply, so that customers can continue backing up their data to our off-site data storage vaults.

We do not sell these generators, but, if you need advise on the use of the Kraftech KT6500W generator with an APC SmartUPS’s, please feel free to call me to chat.


Following the test, our fuel requirements was calculated that a full tank would last just 10 hours, not the 11 hours as advertised.  The difference could be the quality of fuel and electrical load.  We would therefore, require enough fuel to fill the tank 2.4 times to cater for our requirement to run for 24 hours.  As a fuel tank holds 15litres, we would require a fuel store of 30litres in addition to a 15litre full generator tank.  This overall 45litres would give us a maximum run time of 30hours nicely exceeding our 24hour requirement in case of varying fuel, temperature, electrical load.

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