On Apr 18, 9:35*pm, "HeyBub" wrote:
wrote:
On Apr 17, 3:50 pm, "HeyBub" wrote:
Robert11 wrote:
Hello,

Having a new service box installed in a residence.

Electrician has never used these before, so thought I'd ask here.

Was thinking of purchasing, and having him install, an Intermatic
Whole House Surge Suppressor
Model 4870 in the new box. Have had several large lightning storms
in the past, and one nearby strike fried the control board on our
furnace ! The Intermatic unit isn't all that expensive, about $80
or so.
Any of you folks ever used this model ?

Worth doing ? Thoughts on ?

BTW: If they do ever take a big hit, do they (usually) fail open or
closed ?

e.g., would the MOV's be shorting the hot to neutral/ground after a
big hit, such that the unit would have to be removed prior to
re-initiating service ?

Intermatic surge protectors do not use MOVs - they are electronic.

What is this claim based on? * *If they don't use MOV's what exactly
do they use? * Also, this would seem to imply that MOV's are not
considered electronic components, but I believe by any reasonable
definition, they are electronic components.

You're right, of course. MOV are classified as "electronic" components. But
metallic-oxide-varistors work like reverse fuses: they short their terminals
together. And, like fuses, they (usually) only work once with no indication
(other than sometimes smoke) that they won't work again.

Sophisticated electronic circuitry can bleed off surges to ground and
continue to function indefinitely. It is the existence of this circuitry
that's the difference between a $3.00 "surge-suppression" outlet strip and a
$50.00 one.- Hide quoted text -

- Show quoted text -


I think I've answered the question myself. Below is an excerpt from
Intermatics datasheets from both a residential and also a commercial/
industrial unit that clearly say both do in fact use MOV's and say
nothing about any alternate "sophisticated electronic circuitry." I
don;t know of any such alternate components that can handle the huge
currents that MOV's can which is why they are used in all the surge
protectors that I've seen.

If you have any alternate reference, we'd like to see it.


Residential:
Features and Applications:
The IG1240RC features six modes of protection and is recommended for
residential and light commercial applications.
It is intended for installation on 120/240 volt AC panels. The
IG1240RC incorporates the newest developments in MOV
technology and provides individual component thermal protection and
monitoring.

Commercial:
For installation in Category "C & B" locations
! Service Entrance, Distribution Panels and Sub-panels
! Parallel installation
! 125k Amps Peak Surge Capacity per mode
! All mode suppression for systems with a neutral
! Line-to-Line, Line-to-Neutral, Line-to-Ground, Neutral-to-Ground
! 6 mode suppression for systems with no neutral
! Line-to-Line, Line-to-Ground
! Integral Disconnect Switch with safety interlock
! Easily replaceable master surge module
! 40k Amp MOVs
! 200k AIC Surge Rated Fuses