Re: Whole house surge protectors

In article <LJgqf.20479$U06.8447@xxxxxxxxxxxxxxxxxxxxx>, Ignoramus32515 <ignoramus32515@xxxxxxxxxxxxxxxxxxxx> wrote:
>On 21 Dec 2005 09:38:07 -0800, Tim Shoppa <shoppa@xxxxxxxxxxxxxxxxx> wrote:
>> Ignoramus wrote:
>>
>>> Is a WHSP something that is much more than
>>> a (hopefully) beefy MOV in a steel box?
>>
>> They are typically two beefy MOV's (hot1-to-ground and hot2-to-ground)
>> or three beefy MOV's (above plus hot1-to-hot2) in a sand-filled metal
>> box. Most also have a little LED telling you that you're "protected" (I
>> think this works on a few mA leakage current through the MOV when the
>> MOV has not yet failed open.)
>>
>> These are typically installed behind 15 or 20A breakers (at least the
>> smaller ones designed for say 200A panels).
>>
>>> 2. Can I, instead of buying a WHSP, just
>>> buy properly rated MOVs and install them at the
>>> service panel? (from each power leg to ground,
>>> I suppose).
>>
>> You could, but you'd then face the never-ending battle of getting your
>> local electrical inspector to approve something that isn't UL listed.
>> MOV's hit with a big surge really do explode into tiny little pieces,
>> having those pieces flying about inside your panel isn't the most
>> desirable thing. Sometimes they fail shorted, other times they fail
>> open.
>>
>>> Any thoughts?
>>
>> Putting the protection at the service panel (where presumably you've
>> got a nice good low-impedance path to ground) is generally a better
>> idea than installing it far away from ground.
>
>Thanks. I read some articles suggesting that WHSP are rated for higher
>voltage and are not effective for protecting electronics, only motor
>loads (see, for example, howstuffworks.com, I can provide a reference).

My electric company charges for their device on a monthly rate of
$5. Imk pretty sure some kind of protection insurance is provided, but
at least the intention is to protect your stuff.

greg

>I also want some clarification regarding path to ground and such.
>
>If an electrical surge comes through the electrical line, and a surge
>protector shunts it to ground/neutral (both wired to the same point on
>the panel), and the device that's being protected is insulated from
>ground (say, it is in a wooden cabinet), then would it be beneficial
>for this circuit to also have WHSP?
>
>Also, would a decent UPS such as a APC 2200 (I got four for $60
>yesterday) be sufficient? We just bought an expensive electronic
>consumer appliance and I want to protect it. Hence my question.
>
>i
>
.

Quantcast