Medical UPS System
Medical online UPS
If there is a requirement for a UPS system that is to be used in the vicinity of a patient then that UPS should be compliant with the requirements of the standard EN60601-1, or equivalents IEC60601-1, UL2601-1. These standards define the requirements for electrical safety and the main difference between this and the traditional UPS standards is the very strict limits on earth leakage.
Standard UPS limits under 3KVA can have earth leakage of no more than 3mA, and with EMC filters employed you will normally find pluggable UPS systems to have earth leakage in the 1 to 2mA region, whereas the medical standard calls for earth leakage to be no more than 300?A, a factor of 10 more stringent. (EN60601 goes into a lot more detail, but the rest of it is pretty much the requirement for medical devices, and a UPS is not a medical device).
As a result there is niche for UPS systems that fall into this category for patient vicinity applications. So when is a UPS in the vicinity of a patient? Well, this used to be well defined by drawing an arbitary box around the patient and figuring out where the UPS can go, however, now the method employs a risk assessment method, so basically you work out the liklihood of the patient touching the UPS and potentially interfering with any equipment he has attached to him at the time. Typical applications for this include patient monitors, ultrasound systems, PC’s etc, however the manufacturers of these UPS systems put a big disclaimer that under no circumstances should they be used on life support applications. I guess this is just because of the risk of being sued if something goes wrong with the system.
Powervar and Oneac manufacture a range of systems to fulfill this requirement. Powervar has a wider range and are true sine wave VI (Line Interactive) products. Oneac’s (part of Chloride) have extended run capabilities and are slightly cheaper as they have a pseudo-sine inverter (OK – a square wave). [Aside: Come on Oneac - why not make this product sine wave when you're known for great power quality products???].
Medical offline UPS
Widely used in Small and Medium offices, Shopes and Home applications our interactively designed offline UPS of Low power is controlled by fully digitized microprocessor. Based on advanced ABM technology offline UPS has surge protection as well as Short circuit and overload protection. Its modern energy saving function and automatic charging make it extremely reliable.
• MOSFET Based PWM Technology
• Wide Range in built Automatic Voltage Regulator
• Intelligent CVCC Charger for prolonged battery life
• Option of heavy-duty charger for high capacity batteries
• User friendly indications for mode of operation & fault status
• Generator Compatible
On line UPS connection to the user is automqatically, so
there is an electical interlock between it and power
network . The logic of this inter lock is when power
network is on the UPS is diconnecterd from the user and
when power network is off, the UPS become connecterd to the
In addition, on line UPS are used supply some important
equipment in some applications permanently such as process
computer, Medical equipment,PLC or realys in industrial plants.
Off line UPS connection to the user is manually. So when
the power network is off, somebody has to connect the UPS
to the user by closing a breaker or contactor.