Power supply: The need for voltage regulators, transformers and adaptors

Another key consideration for any medical equipment that requires electricity is power supply. Because the need of different voltage on equipment may require additional supplies to be sent with the equipment to enable it to work.

The two most common issues to be aware of are:

• Erratic power supply

• Different voltage levels for power supply

Issue 1: Erratic power supply

Health facilities in low-resource settings are often affected by erratic power supply and problems, caused by a number of factors:

• Scheduled blackouts – The health facility’s mains power may only be available for certain periods of the day.
• Unplanned blackouts – Health facilities experiencing unpredicted main power cuts at random during the day and night.
• Brownouts – When the voltage (or the amount of power available) at a health facility drops below a suitable range. For example, Bradley et al 2011’s study of power interruptions on paediatric wards in Gambian health facilities found that the facility with the worst power supply had 56 brownouts per day.¹
• Surges – When the voltage at a health facility surges above a suitable range. This often happens when power resumes after a blackout

Each of these can damage electrical equipment (including medical equipment) and, as a result, put patients at risk.

Possible solutions to combat erratic power supplies:

• Installing voltage regulators – Also known as surge protectors, these control the amount of power supplied to the facility, and in turn, the medical equipment.
• Uninterruptible power supplies (UPSes) – These function like a voltage regulator and a battery. They regulate the voltage and have an in-built battery that charges while power is being supplied and turns on automatically to run the equipment when power is out.

Issue 2: Different voltage levels for power supply

Different countries, even developed countries, have different voltage levels for their power supply. For example: in the UK single-phase mains power is supplied at 220 volts/50 Hertz, while in the USA it is provided at 110 Volts/60 Hertz.

Supplying equipment that uses the ‘wrong’ voltage can, as a result, be very problematic.

Check both the situation in the country you are buying the equipment from, and the country that you are providing the equipment to. If they have different voltage levels, or different plug shapes, you will likely need to supply the additional resources:

• Transformers – to convert the voltage to the appropriate level.
• Adaptors – to convert the plug and pins of the equipment to the correct configuration. Glue these on to make sure they stay attached!

If you need to include voltage regulators, UPSes or transformers, it’s best to look at the local market (in the country receiving the equipment) first. They are usually relatively inexpensive in local markets because they are often widely available.

Of course, all of this will depend on the particular circumstances of the healthcare facility you are donating to, and the type of equipment you are donating.

Ask local electricians and biomedical engineers for help and advice. Ask the manufacturer about specific power requirements for the equipment.

_{Reference
¹ Bradley B et al, ‘Assessment of Power Availability and Development of a Low-cost Battery-Powered Medical Oxygen Delivery System: For use in low-resource health facilities in developing countries’, 2011 IEEE Global Humanitarian Technology Conference (GHTC). Seattle, USA: IEEE; 2011. pp. 148–53.}