Keeping your UPS running

  • First time fix rate of 95%
  • Comprehensive spares held all over the UK
  • 16 fully trained technicians

Remedial Repairs

Having a service agreement means that any remedial works which may be required are picked up early, allowing you time to schedule the work into your financial planning. This will cause minimal disruption to your business and will prevent unnecessary downtime in the future.

If you do not have a service agreement, that is not a problem. Constant Power Services can offer a one-time repair for your UPS or a HealthCheck if you are not able to identify if you have a problem.

UPS alarms

As part of the building management systems and IT rooms, your Riello UPS will identify and raise an alarm to notify you, if and when something is wrong.

However identifying whether your UPS requires immediate repairs can be difficult and trying to locate the service records or user manual is not always easy.

Constant Power Services have provided some of the more common alarm codes for your information.

Need help identifying your UPS alarm code?

Alarm Code


The Fix



Load powered from bypass line



Battery operation



UPS locked: load not powered



UPS locked: load powered by bypass line



BOOST stage or battery charger locked - load not powered



Manual bypass active



Command active to power the load by the bypass line (from the panel)



End of discharge pre-alarm



Maintenance of the UPS must be performed



Maintenance of the batteries must be performed

Further Faults and Causes

Constant Power Services are always on hand to discuss any potential problems or queries you may have with both existing installations and new. Below we have described some common or possible faults that may occur and the reason for these.


Possible Causes

Mains Failure or Input Switch Open

The UPS is supplying the load from the battery

1. There is a power cut and the UPS operating correctly

2. If the UPS displays the input voltage & frequency, check to see whether they are present and correct. If the voltage or frequency is too low or high the UPS will operate on battery.

3. A Breaker has tripped upstream from the UPS. Check why the breaker has tripped, and if safe to do so reset the switch.

The UPS is alarming bypass fault

The bypass voltage or frequency is out of limits to be able to feed the load:

1. Check the Bypass voltage & frequency. It is likely either the mains voltage is low or high

The UPS is operating from a generator with unstable frequency or poor quality waveform.

3. There is a power cut on the bypass supply and the UPS operating correctly.

4. A Breaker has tripped upstream from the UPS. Check why the breaker has tripped, and if safe to do so reset the switch.

The UPS has Asynchronous alarm

The bypass frequency is out of limits or rapidly changing:

1. It is likely the UPS is operating from a generator with unstable frequency or poor quality waveform.

Battery not present or fault

The UPS has tested the battery and found some issue so that full autonomy is not available:

1. There are low battery blocks within the battery.

2. The battery has been disconnected from the system by the opening or a fuse or switch.

3. The battery is low following an extended

High Temperature or fan fail

There is a high temperature within the UPS system:

1. Check the ambient temperature is within the UPS specification.

2. Check that all the fans are operating correctly

3. On older UPS systems a excessive temperature can indicate leading power factor outside the UPSs limits (effectively an overload).

4. There is excess heat being generated by a fault battery, Check the battery and Isolate is necessary


There is an overload on one or more phases of the UPS output:

1. TCheck for fan heaters, kettles or other high power items on the UPS output

2. For three phase UPS Check if the load is balanced evenly across the phases, it may be necessary to move some load to another phase

Request a User Manual

To request a UPS user manual please fill in the form below and we will send it to you as soon as possible.

Signs that your UPS may need attention

Like anything in life, ageing is a natural process. The UPS is continually working to provid support to your business and infrastructure and has consumable parts which through usage will require changing.

If an alarm code has sounded you can contact Constant Power Services and we will advise you on the next course of action. If you have been advised when a service visit has been carried out, that some of your components have reached the end of life, we can provide a quotation to replace them.

Alternatively, if your UPS is displaying any of the below symptoms please give us a call.

Batteries are integral to the operation of your UPS.

Battery Failing

A UPS system is heavily reliant on the health and running of the batteries. Signs that would indicate a potential problem would be:

  • Smelling sulphur (rotten eggs)
  • Spotting deformation of the batteries
  • Traces of leaking acid and terminal corrosion.

If your installation is showing any of these signs, please get in touch.

Alarm sounding

There could be many reasons why an alarm is sounding:

  • To inform you that a service is due
  • Unit is on bypass
  • Battery failure
  • From a mains failure

If the alarm code you see on your UPS is not listed on our above alarm code help, please get in touch with us.

Contact Constant Power Services to help identify and resolve why your alarm is sounding.

Like a car, your UPS requires maintaining and servicing.

Consumable failure

All consumable parts come with a recommended life span, without routine yearly maintenance it is quite possible for things to fail.

You can stop this happening by simply keeping up with your maintenance visits.

Signs that your UPS may need attention

Now that your UPS is fully operational, why not take a look at our service contracts and find the package that suits your business needs. With guaranteed 4-hour call outs and a whole range of other benefits, Constant Power Services ensures the maintenance of your UPS system for the future.

Find out more

If you would like further information on any of our services or have a question for our expert Sales and Project team please get in touch

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