The electrical isolation protecting against shock limits the currents through it to the allowable values, which apply in any combination of operating temperature after humidity preconditioning, after any required sterilisation, in normal condition and in each 8.7.2 single fault condition, in stand-by and full operation with any mains switch in any position, at the highest rated frequency and at 110 percent of the highest rated mains voltage. Single fault conditions are those of 8.1 except that insulation backed by a protective earth is shorted only where 8.6.4 allows higher earth impedance, for earth leakage current, the only fault applied is breaking the supply conductors one by one, currents are not measured with one part of double insulation shorted, and faults are not combined with the special test conditions of mains voltage on applied parts or on unearthed enclosure parts. Allowable values, measured through the frequency-weighted measuring device (about 1,000 ohms, characteristics of Figure 12) for a.c., d.c. and composite waveforms: patient leakage and patient auxiliary currents per Tables 3 and 4 by applied part type (a.c. from 0.1 Hz), touch current 100 microamps normal and 500 microamps single fault, earth leakage 5 mA normal and 10 mA single fault (higher permitted for permanently installed equipment on its own circuit), functional earth conductor current of non-permanently installed equipment 5 mA and 10 mA, and no leakage current above 10 mA r.m.s. unweighted in any condition. Measurements are made at operating temperature, reducible where circuit examination shows no possibility of the hazardous situations of 13.1; single-phase equipment is tested at both supply polarities and internally powered equipment without a supply connection; equipment is connected by its own cord, by a 3 m or specified detachable cord, or by the shortest connection for permanently installed equipment, with applied parts and patient cables on an insulating surface about 200 mm above earthed metal in the worst position; the measuring instrument has at least 1 megohm input, no more than 150 pF, true r.m.s. from 0.1 Hz to 1 MHz within 5 percent, with a 1 kilohm non-inductive resistor for currents above 1 kHz that could exceed 10 mA. Earth leakage is measured for class I (and class II with a functional earth per 8.6.9) as the aggregate into the installation earth, with a manufacturer-specified procedure for fixed equipment earthed through the building; touch current between earth and each unearthed enclosure part, between unearthed parts, and from normally earthed parts with the earth interrupted, using 20 by 10 cm foil on insulating enclosures moved for the worst value and enlarged to the contact area, plus 110 percent of maximum mains voltage on signal input and output parts at the worst pin configuration; patient leakage from the patient connection to earth with insulating enclosures on an earthed plate, additionally with 110 percent of maximum mains voltage on the patient connections of F-type parts (other unearthed metal parts and other patient connections earthed), on signal input and output parts, and on unearthed metal accessible parts for unearthed type B and BF connections unless separation is shown adequate, insulating applied parts covered with foil or immersed in 0.9 percent saline, fluid patient connections replaced by saline with an electrode, measured from all connections of a function together for type B and BF and from every connection in turn for type CF, using whichever specified detachable part gives the worst result, and the total patient leakage measured with all connections of all applied parts of one type joined; patient auxiliary current between each patient connection and all the remaining ones; and where equipment has several patient connections it is examined with connections disconnected, and disconnected and earthed, where circuit examination shows the currents could rise.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.