Guidelines for Uninterruptible Power Supplies

The design, selection, installation and use of UPSs and DC power supplies for marine applications come under the spotlight in ‘Guidance on the Design, Selection Installation and Use of Uninterruptible Power Supplies Onboard Vessels’ (IMCA M 196), a new publication from the International Marine Contractors Association (IMCA).

There is a wide variation in the cost, quality and capability of UPSs and purchasers should carefully consider and understand the required application and the electrical and environmental conditions in which the UPSD or DC power supply will be expected to operate. It is far from being a case of ‘one size fits all’. Features and levels of performance cannot be taken for granted and standards for UPS design assume that much of the specification for performance will be agreed between the purchasers and the supplier. Simply making reference to a particular standard in a specification document does not necessarily guarantee the unit will be fit for purpose.

In addition to poor choice of equipment for particular applications, the investigation undertaken by those involved in the preparation of our new guidance revealed that premature battery failure is a key issue in UPS reliability and maintainability. Thus the guidance concentrates heavily on the maintenance and testing of batteries and on the advantages and disadvantages of different battery types.