H
HenryC
I hope this can be useful to others too:
According to 60601-1 applied parts are considered defibrillator protected if, upon testing with a 5KV defib-like pulse on the part, no transient above 1V appears on the enclosure and other accessible parts of the instrument. Obviously the instrument should also withstand this pulse, i.e. should work properly and safely after the pulse, to be considered defib protected.
BUT, 60601-1 also states in 8.9.1.15 that defib protected applied parts require >4mm clearance/creepage.
Here come the 2 questions:
1. >4mm is needed according to 60601-1, but between the applied part and what? which parts/elements of the front-end circuit should be separated by at least 4mm to achieve defib protection? what is the rational for this in the context of defib protection?
2. I am assuming that often a front-end (for example for an ECG) is designed with components such as GDTs, resistors, capacitors, TVS, etc. so that the defib transient is shunted very close to the input port where the electrode is connected. why 4mm then? and again where? only if physical separation is deliverately/by-design used as a MOPP/MOOP in the defib circuit?
Thanks in advance
According to 60601-1 applied parts are considered defibrillator protected if, upon testing with a 5KV defib-like pulse on the part, no transient above 1V appears on the enclosure and other accessible parts of the instrument. Obviously the instrument should also withstand this pulse, i.e. should work properly and safely after the pulse, to be considered defib protected.
BUT, 60601-1 also states in 8.9.1.15 that defib protected applied parts require >4mm clearance/creepage.
Here come the 2 questions:
1. >4mm is needed according to 60601-1, but between the applied part and what? which parts/elements of the front-end circuit should be separated by at least 4mm to achieve defib protection? what is the rational for this in the context of defib protection?
2. I am assuming that often a front-end (for example for an ECG) is designed with components such as GDTs, resistors, capacitors, TVS, etc. so that the defib transient is shunted very close to the input port where the electrode is connected. why 4mm then? and again where? only if physical separation is deliverately/by-design used as a MOPP/MOOP in the defib circuit?
Thanks in advance