Hmmm. That's a tougher one. Mostly I use the Polyphasers (PLDO-120US-15A
or -20A) at sites that don't have facility-wide protection. The TrippLite
Isobar Ultra series is another (ISOBAR8ULTRA et al). The Isobars also have
a $50,000 equipment warranty (can't say I've ever had to use it, don't know
how much red tape there is to go through). I like the Polyphasers because
it's designed to mount to a ground panel/bus bar, so I mount it to the bus
bar that has all of my other arrestors (coax, telco, etc.) on it to provide
a common-point ground. The Isobar doesn't have provisions for direct
grounding - it relies only on the equipment grounding conductor in the AC
cord, but the TrippLite has arguably better EMI/RFI filtering than the
Polyphaser.
--- Jeff WN3A
> -----Original Message-----
> From: Repeater-Builder@yahoogroups.com
> [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Chuck Kelsey
> Sent: Tuesday, June 08, 2010 4:48 PM
> To: Repeater-Builder@yahoogroups.com
> Subject: Re: [Repeater-Builder] MOVs for power supply primary
>
>
>
> OK, I should have been more specific. What would be a
> reasonable unit for a
> repeater site that may have only a couple thousand dollars worth of
> equipment inside?
>
> Chuck
> WB2EDV
>
> ----- Original Message -----
> From: "Jeff DePolo" <j...@broadsci.com <mailto:jd0%40broadsci.com> >
> To: <Repeater-Builder@yahoogroups.com
> <mailto:Repeater-Builder%40yahoogroups.com> >
> Sent: Tuesday, June 08, 2010 4:22 PM
> Subject: RE: [Repeater-Builder] MOVs for power supply primary
>
> >
> > 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
>
>
>
>
>
