Preparation for Use
MOBILE WORKSTATION WM-NP2
54
(ii) The total earth leakage current from a combination of medical equipment is above
0.5mA (0.3mA in North America). The separation transformer must be used to supply
sufficient of the medical electrical equipment to reduce the total system earth leakage
current to below the above limit, as long as the maximum transformer rating is not
exceeded. High intensity light sources use arc lamps, which require a high start-up
current. It is not recommended for these to be supplied from the transformer, otherwise
its maximum rating may be exceeded. The transformer may also be used to supply
ancillary equipment forming part of the system as long as the maximum transformer
rating is not exceeded.
Some system installations, for instance those using two mobile workstations, may require two
separation transformers to be fitted. Extension cords and additional multiple socket-outlets must
not be connected to the system.
NOTE
• The total impedance of the protective earth path for a system may be up
to 0.4
or higher if the conditions of clause 8.6.4b) of EN 60601-1 / 18g)
of IEC/UL 60601-1 are satisfied.
• The power outlets should only be used for powering equipment which
forms part of the endoscopy imaging system.
• All equipment forming part of the system should be powered from the
transformer, unless appropriate isolation is employed as described in
Annex I of EN IEC 60601-1:2006 / Annex EEE of IEC 60601-1-1:2000.
This particularly applies where ancillary equipment (as described in (i)
above) forming part of the system is remotely situated, or where signal
input and signal output parts are coupled between the medical electrical
system and a facility’s data network.
• Standards applicable to medical electrical equipment:
EN 60601-1:2006, IEC 60601-1:1988, UL 60601-1:2003, CAN/CSA
C22.2 601.1 M90
• Standards applicable to medical electrical systems:
Clause 16 of EN 60601-1:2006, IEC 60601-1-1:2000
CAUTION
Failure to observe the above mentioned points could result in the
isolation of the entire system being compromised, defeating the
protection provided by the transformer in a single fault condition.
