SAFETY ACTION NOTICE
ESTATES AND FACILITIES EQUIPMENT
SAN(SC)09/01
14 APR 2009
Facilities
Page 1 of 2 Pages
Theatre operating lamps:
precautions against electrical supply failure
SUMMARY
Operating theatre lamps should continue to function on battery if the normal electrical supply fails.
Consideration should also be given to battery back-up in case the operating lamp control unit fails.
BACKGROUND
1. A number of incidents have occurred in which theatre operating lamps ceased to function due to a
component failure in the lamp control unit (the control unit is separate from the lamp). Although
the theatre’s essential electrical supplies, including the operating lamps, were supported by an
Uninterruptible Power Supply (UPS) there was no dedicated battery backup supply to maintain the
operation of lamps in the event of a fault on the control unit (or anywhere between the UPS and the
lamps).
2. The system involved in these incidents was the WPS 362 Energix supplied by Maquet Ltd to
control the electrical supply to main operating and satellite lamps. However, the issues highlighted
in this notice are not confined to this make and are relevant to all theatre operating lamps and
control systems.
3. In collaboration with Scottish Healthcare Supplies, a Customer Notification Letter was sent on 17
February 2006 to all hospitals with Maquet WPS 362 Energix units indicating that a battery backup
facility was required to maintain power to the lamps in the event of a control unit failure. At the
time of purchase of the operating lamps involved in the incidents, a battery back-up system was
available as an accessory. However, this was not requested. As the UPS system was not connected
directly to the operating lamps, it could not provide power when the operating lamp control system
failed.
4. SHTM 2011 Emergency electrical services 1, Part 2 Design considerations states:3.20 Provision of a 24V low capacity battery of at least one hour duration is required as an
emergency alternative supply for main and satellite operating theatre table luminaires used in all
forms of acute surgery. Figure 4 shows a typical circuit. Fully charged battery powered hand
torches should always be available.
5. IEE Guidance Note 7: Special Locations 2 (as interpreted by the Annex to MEIGaN 3) states:In the event of a voltage failure of one or more line conductors at the distribution board, a special
safety power supply source shall maintain luminaires of operating theatre tables and other essential
luminaires, e.g. endoscopes, for a minimum period of 3 h. It shall restore the supply within a
changeover period not exceeding 0.5 s.
Suggested Distribution
Capital Planning & Design
Risk Management
Accident & Emergency
Estates/Facilities
Authorised Persons (LV)
Health & Safety
Authorising Engineers (LV)
Operating Departments
HEALTH FACILITIES SCOTLAND
Gyle Square Edinburgh EH12 9EB
A Division of the National Service Scotland for NHSScotland
CONTACT EMAIL: iric@shs.csa.scot.nhs.uk
WEBSITE: http://www.hfs.scot.nhs.uk/
FAX: 0131 314 0722
N:\WORD\HAZ\IRIC PUBLICATIONS\FINAL SAN\SAN0901.DOC
SAFETY ACTION NOTICE
ESTATES AND FACILITIES EQUIPMENT
SAN(SC)09/01
14 APR 2009
Facilities
Page 2 of 2 Pages
Theatre operating lamps:
precautions against electrical supply failure
6. BS EN 60601-2-41 also refers 4.
ACTION
7.
This notice should be brought to the attention of all appropriate managers and staff.
8.
The electrical power supply to newer theatre operating lamps (i.e. theatres designed from June
2005 onwards) should be backed up by a battery system that will function for a minimum of 3
hours in the event of failure of the normal electrical supply. Older theatre operating lamps (i.e.
theatres designed before June 2005) should have a battery system that will function for a
minimum of 1 hour in the event of a mains failure or failure of the theatre lamp control unit.
9.
Consideration should be given to providing a dedicated battery support unit wired directly to the
lamp heads and which will maintain their function in the event of failure of the electrical supply
at any point (including the lamp control unit). This may require existing battery back-up (or
UPS) systems to be upgraded or supplemented.
10.
The need for additional battery back-up, its position relative to any operating lamp control unit,
and the time required to maintain lamp function, should be decided following a risk assessment
which takes account of:
a)
b)
c)
d)
11.
the likelihood of failure of the normal electrical supply,
the likelihood of failure of any control unit,
the expected use of the operating theatre,
the consequences to patients should the operating lamp fail during surgery.
Tests should be carried out to confirm that operating theatre lamps will function as intended in
the event of a loss of normal electrical supply or failure of any operating lamp control unit, i.e.
for at least three hours for theatres designed after June 2005 or 1 hour for earlier theatre designs.
REFERENCES
1
Scottish Health Technical Memorandum SHTM 2011 Emergency electrical services, Part 2 Design
considerations, Property and Environment Forum Executive, June 2001
2
IEE Guidance Note 7: Special Locations 2nd edition [IEE], 2003, ISBN: 0852969953
(see section 10.12)
3
Healthcare interpretation of IEE Guidance Note 7 (Chapter 10) and IEC 60364-7-710 for Electrical
Installations in Medical Locations, Annex to MEIGaN, June 2005 revised September 2007
4
BS EN 60601-2-41: 2000 Medical electrical equipment. Particular requirements for the safety of
surgical luminaires and luminaires for diagnosis (see Clause 49).
HEALTH FACILITIES SCOTLAND
Gyle Square Edinburgh EH12 9EB
A Division of the National Service Scotland for NHSScotland
CONTACT EMAIL: iric@shs.csa.scot.nhs.uk
WEBSITE: http://www.hfs.scot.nhs.uk/
FAX: 0131 314 0722
N:\WORD\HAZ\IRIC PUBLICATIONS\FINAL SAN\SAN0901.DOC