Maximum Mains Voltage (clause 8.5.3)
- Thread starter phase90
- Start date
From the IEC 60601-1 ed. 3.1, Clause 8.5.3:
The MAXIMUM MAINS VOLTAGE shall be determined as follows:
-for single-phase or d.c. SUPPLY MAINS powered ME EQUIPMENT, including INTERNALLY POWERED ME EQUIPMENT that also has a means of connection to a SUPPLY MAINS, the MAXIMUM MAINS VOLTAGE is the highest RATED supply voltage; unless this is less than 100V, in which case the MAXIMUM MAINS VOLTAGE is 250 V;
-for polyphase ME EQUIPMENT, the MAXIMUM MAINS VOLTAGE is the highest RATED phase to neutral supply voltage;
-for other INTERNALLY POWERED ME EQUIPMENT, the MAXIMUM MAINS VOLTAGE is 250 V.
The clause talks about both single phase (AC) and DC type (including battery) sources. Does one interpret the voltage as AC for AC type and DC for DC types? Or for VAC regardless of the the source?
The MAXIMUM MAINS VOLTAGE shall be determined as follows:
-for single-phase or d.c. SUPPLY MAINS powered ME EQUIPMENT, including INTERNALLY POWERED ME EQUIPMENT that also has a means of connection to a SUPPLY MAINS, the MAXIMUM MAINS VOLTAGE is the highest RATED supply voltage; unless this is less than 100V, in which case the MAXIMUM MAINS VOLTAGE is 250 V;
-for polyphase ME EQUIPMENT, the MAXIMUM MAINS VOLTAGE is the highest RATED phase to neutral supply voltage;
-for other INTERNALLY POWERED ME EQUIPMENT, the MAXIMUM MAINS VOLTAGE is 250 V.
The clause talks about both single phase (AC) and DC type (including battery) sources. Does one interpret the voltage as AC for AC type and DC for DC types? Or for VAC regardless of the the source?
Seems pretty clear (I am not in medical)...
If it is DC, it is the highest rated voltage unless that is <100 100VDC, in which case it is 250VDC.
If it is polyphase, it is the highest rated voltage.
If neither of these, it is 250V...of either.
Ain't nothing in there that allows cool math to get up to 353...
...but again, I'm not in medical. others here are, and they may chime in.
If it is DC, it is the highest rated voltage unless that is <100 100VDC, in which case it is 250VDC.
If it is polyphase, it is the highest rated voltage.
If neither of these, it is 250V...of either.
Ain't nothing in there that allows cool math to get up to 353...
...but again, I'm not in medical. others here are, and they may chime in.
The reference to 250V is really about some of the special tests in IEC 60601-1 which are based on mains voltages is coming from other sources in the room, not the device itself.
There are (I think) only two related tests: mains on applied part (for BF and CF parts only), and mains on a signal part (if there are no controls from Clause 16, ME systems).
Both of these tests are based on hypothetical mains voltage from the environment, as such it's necessary to establish what mains voltage should be used. If the device is mains powered, then use the rated mains voltage. If not, use 250V. But, if you do end up with this 250V, keep in mind it's just for these tests, and only these tests. Careful reading of the standard is needed as to when it uses "maximum mains voltage".
The voltage is clearly ac, since it is intended to represent mains voltage in the environment. Note that the actual test (mains on applied part/signal part) uses rated mains +10% so the actual test is 275Vrms (389Vp). But if it is applicable, it should only be applied in places where there is adequate insulation (e.g. 1.5kV/4mm for F type applied parts, or an isolation barrier in signal I/O part). You would not apply it just to see what happens.
In Amendment 2 this has been dropped to 240V. This makes sense although it does add to the confusion, since a working voltage of 250V clearly identified that it's just for the special tests; a working voltage of 240V could be misinterpreted as indicating the device has mains
There are (I think) only two related tests: mains on applied part (for BF and CF parts only), and mains on a signal part (if there are no controls from Clause 16, ME systems).
Both of these tests are based on hypothetical mains voltage from the environment, as such it's necessary to establish what mains voltage should be used. If the device is mains powered, then use the rated mains voltage. If not, use 250V. But, if you do end up with this 250V, keep in mind it's just for these tests, and only these tests. Careful reading of the standard is needed as to when it uses "maximum mains voltage".
The voltage is clearly ac, since it is intended to represent mains voltage in the environment. Note that the actual test (mains on applied part/signal part) uses rated mains +10% so the actual test is 275Vrms (389Vp). But if it is applicable, it should only be applied in places where there is adequate insulation (e.g. 1.5kV/4mm for F type applied parts, or an isolation barrier in signal I/O part). You would not apply it just to see what happens.
In Amendment 2 this has been dropped to 240V. This makes sense although it does add to the confusion, since a working voltage of 250V clearly identified that it's just for the special tests; a working voltage of 240V could be misinterpreted as indicating the device has mains
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