Probably the ones I've had the most luck with are the Islatrol series from
Control Concepts. I think they have been bought out by Emerson or Liebert
or one of the other companies that have power divisions. Anyway, they call
these "active tracking filters". They not only are TVSS's but also filter
noise, low-amplitude spikes, etc. Right now I'm typing from a mountaintop
site (broadcast) that we re-built a few years ago. We put in an Islator
I-2100 (120/240V single-phase). The old equipment shelter which had been
here since 1990 had the same model unit. In the 15+ years we've been
managing and maintaining the site, we've had zero surge-related failures,
and this site sticks out like a sore thumb as far as lightning goes. In the
last few years I've used the same series of arrestors for new site builds at
a dozen sites or so and have had no power-related problems.
Others that make comparable-quality products include Joslyn, Transtector,
and Innovative Technologies.
There is one big difference (to me anyway) between TVSS's, that being
whether they are the series or parallel type. Series type takes the utility
service (or transfer switch output if there's a generator too) as its input,
and provides a protected output to feed the panel(s). Parallel type is
typically connected to a breaker in the panel, which puts it in parallel
with all of the loads. I much prefer series. Parallel type can be less
effective because a) there will always be some inductance and resistance in
the wiring between the panel and the protector, b) if the TVSS conducts,
there's a good chance it will trip the breaker in the panel, resulting in no
protection until the breaker is reset, and c) they are much less effective
as a noise filter. The upside to parallel type is they can easily be added
at any time just by popping breakers in the panel and feeding the arrestor.
Series, on the other hand, are in-line with the service conductors, so if
you want to add one (or repair one), you have to take the service down.
Series tends to also be more expensive, especially for three-phase and
unlike parallel type, the price goes up as the current rating goes up for
obvious reasons.
A good 200A single-phase arrestor of the ilk I'm talking about starts at
about $1000 and goes up quite a ways from there. I think these single-phase
I-2100's were in the $2000 range. I recently spec'ed a 120/208 3-phase
Transtector (parallel type) for another site where I'm much less concerned
about power-wise, and that was about $1800. No cheap, but where you're
protecting equipment in the 6 and 7 figure range, it's a no-brainer. If
you're repeater is a Micor mobile and an Astron, it might be hard to
justify... :-)
--- Jeff
> -----Original Message-----
> From: Repeater-Builder@yahoogroups.com
> [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Chuck Kelsey
> Sent: Tuesday, June 08, 2010 11:34 AM
> To: Repeater-Builder@yahoogroups.com
> Subject: Re: [Repeater-Builder] MOVs for power supply primary
>
>
>
> Jeff -
>
> Could you suggest some makes and models and maybe explain why
> they are
> superior to others?
>
> Chuck
> WB2EDV
>
> ----- Original Message ----- >
> > Good surge arrestors/TVSS's are expensive, and like most
> things in life,
> > you
> > get what you pay for. If your site has a good surge arrestor at the
> > service
> > entrance, you really shouldn't need anything extra.
> >
> > --- Jeff WN3A
>
>
>
>
>
