ELECTRICAL SYSTEMS


large acute hospital site. With many years’ experience of designing UPS systems, the duty Authorising Engineer arrived on site expecting to find the usual battery issue of a failed block, with a resultant thermal runaway issue. However, on arrival things were not as expected, and the situation quickly escalated to an intensive investigation, which revealed several electrical risk issues, including: n Equipment service and maintenance issues left unresolved.


n Uncontrolled third-party contractors.


n Dangerous contractor working practices.


n No authorisation for live working issued (with UPS batteries).


n No Live Functional Testing (LF.1) form in place (UPS systems /batteries).


n No limitation of access (air-conditioning unit service engineer).


n Uncontrolled release of dangerous Hydrogen sulphide.


n Fire detector did not activate. n No record in site logbook. n No ventilation/extract system in UPS/ battery room.


Incidents involving UPS systems We are seeing an increasing number of electrical incidents related to UPS systems, and believe a major incident is inevitable. UPS systems are critical to life safety, and should be placed high in any organisation’s safety plan. It is thus essential that management personnel take responsibility for their UPS systems, and ensure that they have robust operational and management structures in place. Otherwise, they may be exposed to legal action at some time in the future.


Emerging AE concerns


With the current drive for decarbonisation under the UK Government commitment (COP21), there is increased emphasis on removing/eliminating gas-fire heating plant and moving to electricity-based systems. This is resulting in a significant increase in the electrical demand on the local District Network Operators’ (DNO) already overstretched supplies. In addition, the new loads are generally ‘air to heat source’ pumps and frequency drives motors on ventilation plant. These introduce significant harmonics, which are reflected onto the DNO network. We are seeing an increase in harmonic distortion on hospital electrical infrastructures which are introducing failures, especially in relation to power factor correction units. It should be highlighted that power factor (PF) correction is no longer relevant,


Design n Maintain five-year reporting on your HV/LV Infrastructure.


n Peer design review should be undertaken on all complex designs.


n Undertake capacity and resilience audits on your DNO supplies to site.


n Ensure that UPS batteries are housed in a cladded rack, with the facility for emergency isolation.


n Battery isolation on the UPS module. n Use of IP2X panels at all times. n Check the integrity & resilience of cooling in UPS rooms.


Operational n Appoint an Authorising Engineer (AE). n Ensure that robust electrical safety policy is both in place and used in practice.


Non-insulated tools for separating a fused battery block – with the use of non-compliant Voltage indicators and a risk of flashover, as some battery blocks may still be charged.


especially in healthcare buildings, and that active Harmonic Distortion (HD) filtration is more appropriate. Therefore, designers need to be challenged in their designs. This is picked up through the AE peer design reviews. In extreme cases, where PF equipment is installed in conjunction with frequency drives, the PF equipment can ignite, causing a fire. This may lead to a HSE reportable incident.


Key focuses of an HSE inspection


Should an electrical incident occur on your site that results in a HSE inspection, among the key areas the


body may focus on are: n Fixed wire testing (Mandatory). n AE report and Executive Summary. n System design and its appropriateness for its function.


n Correct operation against design philosophy.


n An appropriate application of Safe Systems of Work.


n Presence and issue of appropriate electrical safety test equipment.


n Operational management (In practice and with supporting evidence.


Recommendations


In summary, the role and responsibilities of the Authorising Engineer are both extensive and rewarding. The appointment of an AE plays a key part in ensuring that the management team is complying with current regulations and statutory requirements. An appropriately qualified AE can ensure that the design and operation of your premises are effective. We recommend, as a minimum, the following steps:


Bill Reeves


Bill Reeves, BEng, MSc, CEng, MIET, MIHEEM, is an experienced Authorising and Power Systems engineer with detailed knowledge of DNO LV/HV/EHV electricity distribution networks operation. He is extremely conversant with Safe Systems of Work and power systems engineering, and brings extensive District Network Operator (DNO – UKPN) experience, supported by a background in electrical engineering in the water and renewable generation and power quality industries. An Authorising Engineer, and Authorised Person for both HV and LV operations, he holds an IOSH General Certificate, and is CDM trained. A Chartered Engineer with many years’ experience in a wide range of industries – including utilities and flood defence, he holds an MSc in Sustainable Electrical Power Engineering, and an HND in Mechanical Engineering, and sits on the IET Chartership accreditation panel. He joined Eta Projects in March 2020.


January 2022 Health Estate Journal 43


n Formally appoint Authorised Persons (APs).


n Ensure that an electrical Safe System of Work (SSoW) is in place and in operation.


n Ensure the presence of appropriate safety documents for working on UPS systems.


n Ensure Authorisation for Live working issued for those working on UPS / battery systems.


n Introduce ‘Live Functional Testing’ forms (LF.1) when testing /working on UPS systems.


n Ensure ‘Control’ of contractors working on site.


n Ensure that mandatory Inspection and Testing is completed (within five years).


n Ensure regular reviews of report equipment defects (ENA).


n Maintain a ‘Site electrical logbook’. hej


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68