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AC Surge Protection Need Help...

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hussain_kiet

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Hi

We are working on a metering project in which we take 3 phase AC input..
we have used LVM2P-015R10431 protection device...
http://www.konkurel.ru/raychem/2Pro/LVM2P.pdf

the protection is working fine the circuits remains safe when surge comes in but it doesn't reset automatically until done manually by removing power...
 

FvM

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Current and voltage sense circuits can be designed with sufficient surge capability, so only the internal power supply would need explicite surge protection. But it's rather low power and should work with a combination of current limiting resistors and MOV.
 

klystron

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The hold current specification is 0.15 A. Is your steady state load current more than 0.15 A?
 

hussain_kiet

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Thanks for the reply guys...

The hold current specification is 0.15 A. Is your steady state load current more than 0.15 A?

our steady state current is below 0.1 A so i don't thinks thats the problem....

Current and voltage sense circuits can be designed with sufficient surge capability, so only the internal power supply would need explicite surge protection. But it's rather low power and should work with a combination of current limiting resistors and MOV.

can you give a diagram to depict the topology...

the current topology we are using is..
 

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our steady state current is below 0.1 A so i don't thinks thats the problem....
Your result seems to suggest the opposite. Apparently the power supply startup current is holding the PTC fused in tripped state. I thought about replacing the PTC fuse with a fixed resistor of sufficient power rating, but it may be easier to modify the power supply, adding soft start with sufficient delay.
 

hussain_kiet

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We have multiple meters installed on different locations, if that would have been the problem then it should be appearing in all meters but we are facing this trouble in some specific areas where the environment seems to be very noisy in electrical terms....

Now we are thinking to remove the LVM and use a Varistor with high energy rating do you think thats a good idea..?
 

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