Re: Lightning & Surge protection

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As you can see below, coordination between SPD and MCB(F2 in the text) is given by the manufacturer’SPD instructions

extract from IEC 60364-5-534:
“534.2.4 Protection against overcurrent and consequences of an SPD failure
Protection against SPD’s short-circuits is provided by the overcurrent protective devices F2
(see figures in the annexes A to D) which are to be selected according to the maximum
recommended rating for the overcurrent protective device given in the manufacturer’s SPD

moreover the product standard IEC 61643-11 refers to disconnector (overcurrent protective devices) as you can show below:

extract from IEC 61643-11/2005:
” 6.2.7 SPD disconnector
The SPD may have SPD disconnectors (which can be either internal, external or both). Their
operation shall be indicated.
NOTE Installation requirements not related to the SPDs may require additional and/or lower rated overcurrent protective devices.
SPD disconnectors shall be tested with the SPD during the sequence of type tests of 7.7 and
7.8.3, except for RCDs, which are not tested during the operating duty test according to

My advice is to contact manuifacturer’s SPDs and ask to them this coordination table